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American Standard UV05 User's Manual

1. Table 2 Protocol specific communication card installation literature and protocol data Description Manual Unit Ventilator Unit Controller LonWorks IM 729 Communications Module Unit Ventilator Unit Controller JCI N2 Open IM 730 Communications Module Unit Ventilator Unit Controller BACnet IM 731 Communications Module Protocol Data Packet ED 15065 Table 3 Accessory specific installation literature Description Manual MTII Unit Ventilator Controls Installation IM 747 Room Temperature Sensors Installation IM 629 1 ATS Service Cable Installation for Unit Ventilators IM 762 0 McQuay OM 751 Introduction Table 4 Software program literature Description Manual Air Source Heat Pump with Electric Heat Software Model 00 OM 748 Water Source Heat Pump with Electric Heat Software Model 02 OM 749 Water Source Heat Pump without Electric Heat Software Model 03 DX Cooling with Electric Heat Software Model 04 OM 750 DX Cooling Only Software Model 05 OM 751 Electric Heat Only Software Model 06 OM 752 DX Cooling with Hydronic Heat Valve Control Software Model 07 OM 753 DX Cooling with Hydronic Heat F amp BP Damper Control Software Model 08 2 Pipe Hydronic Heat Only Valve Control Software Model 09 OM 754 2 Pipe Hydronic Heat Only F amp BP Damper Control Software Model 1
2. Display Keypad menu item list Abr Description bay Do Default Exhaust Interlock OAD Adjust OA damper position above which the exhaust fan output will be energized a o5 Min Position set point FOAD There is a fixed 5 differential associated with this set point BA o Energize Exhaust Fan Adjust OA damper minimum position when the exhaust interlock input is 5 ob OAD Set point OADE energized RUBI 2 12 ol ad Max Position Set Gamx Adjust OA damper maximum position Rw x 99 Set OA damper lockout feature status 0 disable 1 enable This variable is of OAD Lockout Enable factory set to 1 when the unit is ordered as a recirc unit with no OAD RAGI 9 Adjust OA temperature below which the OA damper closes if the OA damper 35 6 F og OAD Lockout Set point OALS lockout is enabled This variable is factory set to 99 C when the unit is ordered RW x 2 C as a recirc unit with no OAD F l Economizer Enable Set economizer status 0 disable 1 enable RW x 1 EA Economizer OA Temp ETS Adjust economizer OA temperature set point DO NOT lower this set point below Rw x 68 F Set point CCLO or you risk creating a deadband where no cooling occurs 20 C gJ Economizer IA OA Temp ETD adjust economizer IA OA temperature differential RW x 1 8 F 1 C Differential Economizer OA Enthalpy 2 3 25 Btu lb ES Set point EES Adjust economizer OA enthalpy set point RW x 58 kJ kg Econom
3. Air Fan AF Auxiliary Heat End Differential AHED Auxiliary Heat Start Differential AHSD American Standard Code for Information Interchange ASCII American Society of Heating Refrigerating and Air ASHRAE Conditioning Engineers Inc Compressorized Cooling Lockout CCLO Space CO Setpoint COS Chilled Water CW Chilled Water Valve Position CWVP Discharge Air DA Discharge Air High Limit DAHL Discharge Air Temperature DAT Discharge Air Temperature Setpoint DATS Demand Controlled Ventilation DCV DX Cooling Discharge Air Low Limit DXLL Economizer Compare Differential ECD Economizer IA OA Enthalpy Differential EED Economizer OA Enthalpy Setpoint EES Emergency Heat Setpoint EHS Exhaust Interlock OAD Min Position Setpoint EOAD Outdoor Air Temperature Setpoint EOAT End of Cycle EOC EOC OAT Low Setpoint EOCS Outdoor Air Humidity Output EORH Space Humidity Setpoint ERH Economizer IA OA Temp Differential ETD Economizer OA Temp Setpoint ETS Source water in Temperature EWIT Face and Bypass Damper Position FBDP Federal Communications Commission FCC Face and Bypass F amp BP Heating Ventilating Air Conditioning Refrigeration HVACR Heating EOC Valve Setpoint HEOC Hot Water HW Indoor Air IA Indoor Air Fan IAF Indoor Air Temperature IAT Light Emitting Diode LED Local User Interface LUI Mixed Air Low Limit MALL Mechanical Cooling Low Limit Setpoint MCLL National Electric Code NEC Outside Air OA Outside Air Da
4. 0000000 e eee eee 37 External Binary Input 3 0000s 37 External Binary Outputs 0 00 0000s 38 External Binary Output1 ana aaan 38 External Binary Output2 eens 38 External Binary Output 3 20 eee 38 UVC Input and Output Table 40 Diagnostics and Service 41 Alarm and Fault Monitoring eee eee 41 Space Temp Sensor Failure F2 a 42 DX Pressure Fault F 0 0 0 0 ccc eee eee 42 Compressor Envelope Fault F2 A a 42 Discharge Air DX Cooling Low Limit Indication F3 42 Condensate Overflow Indication optional F4 43 Space Coil DX Temp Sensor Failure F5 43 Outdoor Temp Sensor Failure F5 43 Discharge Air Temp Sensor Failure F1 43 Outdoor Coil DX Temp Sensor Failure F8 43 Space Humidity Sensor Failure optional FA 44 Outdoor Humidity Sensor Failure optional Fb 44 Space CO2 Sensor Failure optional FC 44 Change Filter Indication FF aa 44 EPROM Memory Indicator EE a a nananana 44 Configuration Display 00000 eee ee eeee 44 Troubleshooting Temperature Sensors 44 Troubleshooting Humidity Sensors aa a 45 Troubleshooting Carbon Dioxide CO Sensors 46 UVC Configuration Parameters 47
5. Figure 13 Econ state operation occupied mode and auto fan OA Damper at 100 Open IA Fan Low Speed Osan T i i i N i PS OF i PO ES i O i g i i i i i Primary OA Damper at 35 Open H amper at 30 Speed nunakgkinaiFaranababarong gt Cooling 3 So Satisfied 6 gt Warmer Econ Mech State State 1 The Econ Mech state is a normal state during Cool mode The Econ Mech state typically is active in the Cool mode when primary cooling economizer alone is not adequate to meet the cooling requirements and both primary cooling and secondary cooling compressor are available When the Econ Mech state becomes active the OA damper is set to 100 open and the UVC uses the units mechanical cooling capabilities as needed to maintain the effective cooling set point see Space Temperature Set Points on page 26 The UVC monitors the DAT to ensure it does not fall below MCLL Figure 14 Econ mech state operation occupied mode and auto fan OA Damper 100 Open O IA Fan High Speed P Staging Compressor On p Up 4 4 OA Damper 100 Open Pat IA Fan Medium Speed f Osawi Compressor On P TA N d 4 1 s y Staging Down OA Damper 100 Open IA Fan Low Speed Compressor On 22 7 I 7 OA Damper 100 Open vy Secondary IA Fan Low Speed Siiami 5 gt Cooling ir o o o o o 5 5 SR amp ES N AR a
6. Operation Maintenance Manual OM 751 1 Group Applied Systems Part Number OM 751 Date November 2006 MicroTech II Unit Ventilator Controls for AAF HermanNelson Classroom Unit Ventilators MicroTech II ER ravomy Hon ny com veo e HEAT e Low g Na KO DX Cooling Only Software Model UV05 Used with AAF HermanNelson Classroom Unit Ventilator Model AVV Floor Mounted Model AHV Ceiling Mounted Model AZV AZU Floor Mounted Self Contained Air Conditioner IMPORTANT Before unit commissioning please read this publication in its entirety Develop a thorough understanding before starting the commissioning procedure This manual is to be used by the commissioner as a guide Each installation is unique only general topics are covered The order in which topics are covered may not be those required for the actual commissioning 2006 McQuay International AAF HermanNeson Introduction aa NAG Pe an Cae 3 Acronyms Abbreviations 00000 ccc eee e eee ee 5 Getting Started aaa 7 Using the Keypad Display 00 eee eee eee eee 7 Display Format iy alan nee es hee eee Se A pe 7 Keypad Functions 0 00 eee eee 7 Using the Keypad Display cece eae 9 Menu Reference ie dreri dare ieee cea raed ete 9 Description of Operation 12 State Programming 0c cece eee eee 12 UVC UNE MO CS Ta oscar teal UG
7. 27 Proportional Integral PI Control Loops 29 Discharge Air Temperature Control 29 PI Control Parameters cee eee ee 30 Proportional Band 000 c eee eee 30 Integral Times 221 ses Rete ae Oe oe ed a 31 Indoor Air Fan Operation 0000 0c eee eee 31 Auto MODE a cic Na NG eee NGA TANG NAIDAGDAG 31 Occupied Standby and Bypass Operation 31 Unoccupied Operation cee eee 32 Cycle Fan AA 32 GL AA AA Meee 32 Outdoor Air Damper Operation 000000 ee eee 32 Minimum Position 0 00 00 e ee eee eee 32 Economizer Operation cece eee eee 32 Networked Space Humidity Sensor Capability 34 Networked Outdoor Humidity Sensor Capability 34 CO Demand Controlled Ventilation optional 34 Networked Space CO Sensor Capability 34 ASHRAE Cycle Il 35 Compressor Operation ccc eee eee eee 35 Compressor Envelope nananana cece eee eeee 35 Compressor Cooling Lockout 00 00005 35 Compressor Minimum On and Off Timers 36 Compressor Start Delay 0 0000 e eens 36 Outdoor Air Fan Operation 00000 00 ee ee 36 Floating Point Actuator Auto Zero Overdrive and Sync 36 External Binary Inputs 0000 c eee eee eee 37 External Binary Input1 0000 0 eee eee 37 External Binary Input 2
8. Description of Operation PI Control Parameters Associated with each PI loop is a set of two adjustable parameters Proportional Band and Integral Time When the unit ventilator is properly sized for the space the factory settings for these parameters provides the best and most robust control action see Figure 20 If field problems arise first ensure these parameters are set back to the factory default settings If adjustment is required only make small adjustments to one parameter at a time After each adjustment allow enough time for the system to stabilize before making further adjustments If you do not have the means to graph the space performance record the actual measured value and set point for several minutes and then plot the results using a spreadsheet to determine the correct action to change the PI parameter VAN CAUTION Adjusting PI parameters can cause erratic unit operation and potentially damage the equipment PI control parameters should only be adjusted by trained personnel having a complete understanding of how these parameters affect system operation Generally these parameters do not need to be adjusted from the factory default settings Figure 20 Optimized PI loop control Actual Setpoint Proportional Band The proportional band or proportional action causes the controlled output to changes in proportion to the magnitude of the difference between the sensor value and set p
9. External Input Option 1 Unoccupied default BI 7 BI 8 BI 9 BI 10 BI 11 BI 12 DX Press Switch NC Al 1_ IA Temp Sensor T O Al 2 Remote Setpt Adjust Pot Al 3 TOA Coil DX Temp Sensor Al 4 OA Temp Sensor AI 5 JIA Coil DX Temp Sensor Al 6 DA Temp Sensor BI 4 Expansion board xBO 1 External Output Option 1 Lights On Off External Output Option 3 Exhaust Fan On Off default or Auxiliary Heat 1 xBO 3 OA Damper Open xBO 4 OA Damper Close xBO 5 xBO 6 xBO 7 Outdoor Fan xBO 8 Inside Fan Low XAI 1 IA Humidity Sensor xAl 2 OA Humidity Sensor xAl 3 Indoor CO Sensor xAl 4 Field selectable external output options all possible options are shown This is the condensing unit on off signal on split systems Field selectable external input options all possible options are shown DX pressures switch not installed on split systems this input is then wired for constant no fault condition Not installed or wired on split systems Optional xBO 2 PDE om 40 McQuay OM 751 Diagnostics and Service Diagnostics and Service The most important aspect of troubleshooting unit ventilator controls is to isolate the source of the problem into one of two categories 1 The problem resides within the UVC 2 The problem is external to the UVC Under most circumstances the problem is external to th
10. Standby and Bypass Operation During occupied standby and bypass modes the IA fan by default remains On McQuay OM 751 31 Description of Operation Unoccupied Operation During unoccupied mode the IA fan typically remains off and cycles with calls for heating and cooling Cycle Fan The UVC is provided with a Fan Cycling Configuration variable that can be used to force the IA fan to cycle with calls for heating and cooling during the occupied standby and bypass occupancy modes When the fan is off the OA damper is closed McQuay recommends using this feature only when it is acceptable that normal ventilation is not required When the IA fan is set to cycle the UVC is configured to continue fan operation for a time period after heating or cooling is complete Off Delay When the UVC is placed into off mode or shutdown mode the UVC is configured to continue fan operation for a short time period and then shutdown Outdoor Air Damper Operation The UVC is configured for an OA damper operated by a floating point actuator The OA damper actuator contains a spring that ensures the OA damper is closed upon loss of power The floating point actuator is driven by the UVC using two binary Triac outputs The OA damper typically is open to the current minimum position during the occupied and bypass occupancy modes and closed during the unoccupied and standby occupancy modes A Triac output is best tested under load using a 24
11. continuous 3 cycle Space Fan Speed Changes Per Hour example 6 60min 10min maximum of 1 fan speed change every 6 10min when fan in auto Space Fan Run Time Reset reset total run time 1 reset you must return the variable back to 0 0 after reset Compressor Run Time Reset reset total run time 1 reset you must return the variable back to 0 0 after reset Compressor Enable 0 disable 1 enable 1 LI Compressor Minimum On Time 180 sec Compressor Minimum Off Time 300 sec Compressor Cooling Lockout Setpoint CCLO OA temperature below which compressor cooling is not allowed 63 5 F 17 5 C Compressor Envelope Cool Max In 120 F 48 89 C Compressor Envelope Cool Min In 28 F 2 22 C Compressor Envelope Cool Max Out 160 F 71 11 C Compressor Envelope Cool Min Out 40 F 4 44 C Compressor Envelope Cool Max Ratio 0 00 Compressor Envelope Cool Max Offset 88 F 48 89 C Compressor Envelope Cool Min Ratio 0 0 Compressor Envelope Cool Min Offset 4 F 2 22 C Auxiliary Heat Start Differential AHSD degrees above auxiliary heat start point where auxiliary heat ends 2 F 1 C AI Auxiliary Heat End Differential AHED degrees above auxiliary heat start point where auxiliary heat ends 2 F 1 C Ad Auxiliary Heat Configuration 0 normally open heat device hot water valve etc 0 AI 1 normally closed heat device electric heat etc Space Humidity Sensor Enable 0 disable 1 enable this variable will be factory set to 1 when
12. cooling are not available or they are disabled or when an IAT DAT or OAT sensor failure occurs When the Cant Cool state becomes active no cooling is available Special Purpose Unit Modes There are some additional UVC modes that are considered special purpose unit modes These special purpose modes include Pressurize Depressurize Purge Shutdown and Energy Hold Off These modes force the UVC to perform very specific and limited functions Use these with caution and only for short periods as needed McQuay OM 751 21 Description of Operation In each of these special purpose UVC modes if the space temperature drops below EHS and the Emergency Heat function is enabled the UVC is forced into the Emergency Heat mode see Emergency Heat Mode Super State on page 16 and then return once the Emergency Heat function is satisfied Table 9 Actions during special purpose unit modes Acton Indoor air fan Outdoor air Exhaust fan IAF damper OAD output Pressurize High 100 Open off Depressurize Off Closed On Purge High 100 Open On Shutdown Off Closed Off Energy hold off Off Closed Off Pressurize Mode When in Pressurize mode the UVC uses the IAF OAD and exhaust output as needed to pressurize the space The UVC stops all normal heating and cooling but does allow emergency heat if required The pressurize mode can only be accessed via a network connection Depressurize Mode W
13. m Actual Actual Area under ue the curve Setpoint Setpoint The smaller the integral time the faster the output ramps up or down with small changes in the space The smaller the integral time the quicker the system reacts to small changes in the space If the Integral Time is set too small long oscillations occur see Figure 22 In general it is best to start with a relatively large integral time setting the factory default setting is best and adjust to smaller values If you want the system respond strongly to small changes in the space lower the integral time If you want the system to react weakly to small changes in the space adjust the integral time to a higher setting Indoor Air Fan Operation The UVC supports a three speed indoor air IA fan low medium and high The UVC calculates the effective fan speed and operation based on the unit mode the occupancy mode and the values of several network variables Auto Mode The UVC is provided with a user selectable auto fan mode feature When in auto fan mode the UVC uses the space temperature PI loop to automatically adjust the fan speed as needed to maintain space temperature This ensures that the UVC maintains the lowest and quietest fan speeds whenever possible When in auto fan mode a maximum of six fan speed changes per hour is allowed by default This prevents frequent automatic fan speed changes from disturbing room occupants Occupied
14. or other odor generating operations occur within the space Night Purge mode consists of a single UVC state Night Purge 8 Night Purge is a full ventilation with exhaust mode during which room comfort is likely to be compromised Therefore McQuay strongly recommends using Night Purge only when the space is unoccupied When Night Purge mode becomes active the UVC stops all normal heating and cooling Since any new energy used to treat the incoming air would be wasted in the purge process In the Night Purge mode the space fan is set to high speed the OA damper is set to 100 open and the Exhaust Fan binary output see External Binary Outputs on page 38 is set to ON If the UVC is not set to another mode within 1 hour fixed the UVC automatically switches to the Fan Only mode see Fan Only Mode State A on page 15 While in Purge mode the UVC does not maintain DA temperatures If the space temperature drops below the EHS the UVC is forced into the Emergency Heat mode see Emergency Heat Mode Super State on page 16 Figure 8 Night purge state diagram Night Purge UVC Mode Night purge UVC Mode Night purge NA Transition point Fan Only Mode State A The Fan Only mode is provided so that the UVC can be forced into a Fan Only operation via a keypad display or a network connection Fan Only mode consists of a single UVC state Fan Only A When Fan Only mode becomes active the UVC stop
15. Interlock Input Signal This input allows a single set of dry contacts to be used to signal the UVC that an exhaust fan within the space is energized The UVC repositions the OA damper to a user adjustable minimum position Exhaust Interlock OA Damper Min Position Setpoint When the contacts close exhaust fan on signal the UVC uses the value defined by the Exhaust Interlock OA Damper Min Position Setpoint as the new minimum OA damper position regardless of IA fan speed When the contacts open the UVC returns to normal OA damper operation External Binary Outputs The UVC is provided with three binary outputs that provide the functions described below Figure 25 Binary outputs Binary Outputs 3 relay type outputs w signal voltage Output 1 Relay output for light signal Output 2 Fault signal Output 3 Exhaust fan operation default gt or Auxiliary heat device These outputs are relay type outputs that are intended to be used with signal level voltages 24 VAC maximum only For wiring examples see MicroTech II Unit Ventilator Controller IM 747 Note Not all of the functions listed can be used at the same time The UVC is provided with configuration parameters that can be adjusted to select which function will be used for these outputs when multiple functions are indicated below External Binary Output 1 This output can only be used as a signal for space lights Lights On Off Signal This
16. MAGAAN NATAL arcane 13 OFF Mode State 9 uuaa eee eee eee 14 Night Purge Mode State 8 a 15 Fan Only Mode State A a 15 Emergency Heat Mode Super State 16 Auto Modessa cde ea ated hos KAKA bene bok a oy bere AA 17 Cool Mode Super State 2 200020 2 eae 18 Special Purpose Unit Modes 0 00 005 21 Unit Mode Priority o raa eee 23 Occupancy Modes 0000 e eee eee 24 Occupied Mode 2 2 2 2 24 Unoccupied Mode 00 cee eee eee eee 24 Standby Mode 000 0c e eee eee 24 Bypass Mode a a anG Baan BAN e 25 Additional Occupancy Features a 25 Networked Occupancy Sensor Capability 25 Unit Mounted Time Clock a 25 Unit Mounted Tenant Override Switch 25 Remote Wall Mounted Sensor Tenant Override Switch 25 Remote Wall Mounted Sensor Status LED 25 Space Temperature Set Points a 26 Networked Set Point Capability 26 Networked Set Point Offset Capability 26 Networked Set Point Shift Capability 26 Networked Space Temperature Sensor Capability 26 Remote Wall Mounted Sensor with 3 F Adjustment optional eae 27 Remote Wall Mounted Sensor with 55 F to 85 F Adjustment optional eae 27 Effective Set Point Calculations
17. Override Input if there is reason to ensure tenant override does not occur Remote Wall Mounted Sensor Tenant Override Switch The optional remote wall mounted sensors include a tenant override switch This switch provides a momentary contact closure that can be used by room occupants to temporarily force the UVC into the bypass occupancy mode from unoccupied mode Note The Occupancy Override Input can override the tenant override feature For example if the network uses the Occupancy Override Input to force the unit into unoccupied mode then the wall sensor tenant override switch does not operate as expected Therefore McQuay strongly recommends using the Occupancy Sensor Input to control occupancy modes over a network and only using the Occupancy Override Input if there is reason to ensure tenant override does not occur Remote Wall Mounted Sensor Status LED The optional remote wall mounted sensors each include a UVC status LED This status LED aids diagnostics by indicating the UVC occupancy mode and fault condition Table 13 Remote wall mounted sensor status LED Indication LED operation Occupied On continually Unoccupied On 1 second off 9 seconds Bypass On continually Standby On 9 seconds off 1 second Fault On 5 seconds off 5 seconds McQuay OM 751 25 Description of Operation Space Temperature Set Points The UVC uses the six occupancy based temperature set points as the basis to determin
18. deviates substantially more than 10 from the expected voltage replace the sensor In the unlikely event that the CO sensor requires calibration consult the factory for information on obtaining calibration equipment and instructions Table 25 CO versus voltage table CO PPM VDC V CO PPM VDC V 300 1 5 1200 6 0 400 2 0 1300 6 5 500 2 5 1400 7 0 600 3 0 1500 75 700 3 5 1600 8 0 800 40 1700 8 5 900 45 1800 9 0 1000 5 0 1900 9 5 46 McQuay OM 751 UVC Configuration Parameters UVC Configuration Parameters The UVC is been provided with a number of configuration variables as listed in the following table These configuration variables are stored in UVC non volatile memory For a description of supported network variables for each protocol refer to Protocol Data Packet bulletin ED 15065 Table 26 UVC configuration parameters OM 751 Occupied Cooling Setpoint ocs 73 F 23 C Co Standby Cooling Setpoint Scs 77 F 25 C rs Unoccupied Cooling Setpoint UCS 82 F 28 C CU Occupied Heating Setpoint OHS 70 F 21 C Ho Standby Heating Setpoint SHS 66 F 19 C HS Unoccupied Heating Setpoint UHS 61 F 16 C HU Local Bypass Time Tenant override 120 min Space CO Setpoint CO S 1200 PPM Space Humidity Setpoint used with both active reheat and passive dehu
19. keypad display remains at that security level until the next time it is changed Why can t use the MODE or FAN key or adjust Set Point Offset Most likely this is due to the security feature being used If the security feature is set higher than level 0 then some keypad display functionality is locked out To ensure this is not the problem enter the level 0 password then try to use the keypad display again McQuay OM 751 Getting Started Table 6 Keypad display security levels Level Display What is restricted Password 0 ug Default level access all 10 Does not allow set point offset changes 1 ul also locks out keypad display menu 21 access Does not allow set point offset changes 2 uc nor MODE key changes also locks out 32 keypad display menu access Does not allow set point offset changes 3 uz nor MODE and FAN key changes also 43 locks out keypad display menu access Figure 2 Changing keypad display security levels 10 gt 00 gt OPAPP wv gt G Effective Press both Security Scroll Security Select set point 10 sec level O level 2 D3 PH 3 HOH 0 Paseword Scroll Enter Password digit 1 digit 2 NG 2 BOB ue 10 Scroll Enter Effective sat point ON STOP Key and LED Use the ON STOP key to toggle the UVC between OFF mode and running Application Mode Input The ON STOP LED is off when the UVC is in the OFF mode Note When the UVC is in th
20. measure the actual resistance across the two sensor leads 5 Compare the expected resistance to the actual resistance 6 Ifthe actual resistance value deviates substantially more than 10 from the expected resistance replace the sensor Table 23 Temperature versus resistance F C Resistance inohms F C Resistance in ohms 40 40 613 113 45 1195 31 35 640 122 50 1237 22 30 668 131 55 1279 13 25 697 140 60 1323 4 20 727 149 65 1368 5 15 758 158 70 1413 14 10 789 167 75 1459 23 5 822 176 80 1506 32 0 855 185 85 1554 41 5 889 194 90 1602 50 10 924 203 95 1652 59 15 960 212 100 1702 68 20 997 221 105 1753 77 25 1035 230 110 1804 86 30 1074 239 115 1856 95 35 1113 248 120 1908 104 40 1153 Troubleshooting Humidity Sensors The UVC is configured to use a 0 100 RH 0 5 VDC capacitive humidity sensor Each sensor is calibrated according to the table shown VAN CAUTION The humidity sensor is not protected against reversed polarity Check carefully when connecting the device or damage can result Use the following procedure to troubleshoot a suspect sensor 1 Disconnect the sensors output voltage lead from the UVC analog input 2 Using some other calibrated humidity sensing device take a humidity reading at the sensor location 3 Use the humidity reading from
21. or 0 respectively 12 McQuay OM 751 Figure 6 Complete UVC state diagram Description of Operation 9 P Emer gencyHeat Modes uperState FullHeat D HeatMode SuperState ge B I ic E a Ey NightPurge CoolMode SuperState a Econ LM yo B UVC Unit Modes The UVC provides several normal modes of unit operation These include Off Night Purge Fan Only Cool Emergency Heat Auto Heat and Cool Normal UVC modes can contain a single state or several states depending upon the functionality required for each particular mode Each UVC state is assigned a number which can be very helpful when trying to understand which state is currently active within the UVC To view the current UVC state number use the keypad display McQuay OM 751 13 Description of Operation Table 8 UVC state names and numbers State numbers Normal UVC modes State names Decimal ASCII Hay OFF OFF 9 9 57 Night purge Night Purge 8 8 56 Fan only Fan Only 10 A 65 Emergency heat Full Heat 7 7 55 Cant Heat 13 D 68 Heat 5 5 53 Heat Cant Heat 11 B 66 Low Limit 14 E 69 EconMech 1 1 49 Auto Mech 2 2 50 Cool Econ 3 3 51 DA Heat 4 4 52 Cant Cool 12 C 67 Low Limit 15 F 70 VAN WARNING Off mode is a stop state for the unit ventilator It is not a power off state Power may still be pr
22. states are used as a means to group two or more related states into a single control function such as cooling or heating etc States are where all the actual work takes place within each state the UVC enables PI loops and other logic sequences required to control unit ventilator operation within that particular state while other functions and PI loops not needed during that state may be disabled Conditional jumps or transitions are the logic paths used by the UVC to determine which state should be made active these are the questions the UVC continually considers The transition point is simply a point through which a number of conditional jumps meet Think of it as a point where a number of questions must be considered from which the UVC then determines which path is followed and which state is then made active The UVC states and super states are used to define the normal unit modes such as Off Night Purge Fan Only Emergency Heat Auto Cool and Heat The UVC also supports several special purpose unit modes such as Purge Pressurize De pressurize and Shutdown which can be forced via a network connection and override typical UVC operation Note Not all states or modes are available for all UV configurations and some states such as Active Dehum are optional In the state descriptions below the terms saturated high and saturated low indicate that the heating or cooling function being described has reached 100
23. 0 2 Pipe Chilled Water Cooling and Hot Water Heat Valve Control Software Model 11 OM 755 2 Pipe Chilled Water Cooling and Hot Water Heat F4BP Damper Control Software Model 12 4 Pipe Chilled Water Cooling and Hydronic Heat Valve Control Software Model 13 OM 756 4 Pipe Chilled Water Cooling and Hydronic Heat F4BP Damper Control Software Model 14 2 Pipe Chilled Water Cooling Only Valve Control Software Model 15 OM 757 2 Pipe Chilled Water Cooling Only F amp BP Damper Control Software Model 16 2 Pipe Chilled Water Cooling with Electric Heat Valve Control Software Model 17 8 OM 758 2 Pipe Chilled Water Cooling with Electric Heat F amp BP Damper Control Software Model 18 NOTICE This equipment generates uses and can radiate radio frequency energy and if not installed and used in accordance with this instruction manual may cause interference to radio communications It has been tested and found to comply with the limits for a Class A digital device pursuant to part 15 of the FCC rules These limits are designed to provide reasonable protection against detrimental interference when the equipment is operated in a commercial environment Operation of this equipment in a residential area is likely to cause detrimental interference in which case users are required to correct the interference at their own expense McQuay International disclaims any liability resulting from any interference or
24. 0 the unit is ordered with optional humidity sensor Outdoor Humidity Sensor Enable 0 disable 1 enable this variable will be factory set to 1 when 0 the unit is ordered with optional humidity sensor 48 McQuay OM 751 UVC Configuration Parameters OAD Stroke Time 90 sec Split System OA DX Coil Temp used on split system units only to partially disable the compressor envelope by setting the outside DX coil temperature to a fixed valid 327 76 value enter 122 F 50 C on split systems use 327 67 for self contained units 327 67 invalid Application Name and Version Label Compressor Start Delay adjust the compressor delay used to prevent multiple compressor units from starting simultaneously each unit or group of units 0 sec should have a different delay setting Outdoor Fan Delay 10 sec 1 Indicates parameters accessible through the keypad display 2 Requires optional equipment McQuay OM 751 49 McQuay Training and Development Now that you have made an investment in modern efficient McQuay equipment its care should be a high priority For training information on all McQuay HVAC products please visit us at www mcquay com and click on training or call 540 248 9646 and ask for the Training Department Warranty All McQuay equipment is sold pursuant to its standard terms and conditions of sale including Limited Product Warranty Consult your local M
25. Don t care Unoccupied Occupied Don t care Occupied Unoccupied Don t care Bypass Bypass 7 Null default Contacts open Occupied Occupied Contacts Closed Unoccupied Bypass Standby Don t care Don t care Standby Occupied Don t care Occupied 7 7 iad Null default Unoccupied Don t care l Unoccupied Null default Contacts open Occupied Occupied ull ut Contacts closed Unoccupied Unoccupied The occupied mode is the normal day time mode of UVC operation During occupied mode the UVC uses the occupied heating and cooling set points the OAD operates normally and by default the IAF remains on Unoccupied Mode The unoccupied occupancy mode is the normal night time mode of UVC operation During unoccupied mode the UVC uses the unoccupied heating and cooling set points the OAD remains closed and the IAF cycles as needed for heating or cooling The IAF remains off when there is no need for heating or cooling Standby Mode The standby mode is a special purpose daytime mode of UVC operation During standby mode the UVC uses the standby heating and cooling set points the OAD remains closed and by default the IAF remains on 24 McQuay OM 751 Description of Operation Bypass Mode The bypass mode also called Tenant Override is the equivalent of a temporary occupied mode Once the bypass mode is initiated it remains in effect for a set period of time 120 minutes default During the bypass mode the UVC uses the occ
26. EconPl SatHi AND MechCool Available MechPl SatLow 3min AND EconMechTimer Expired MechCool Available Space HighCO2 5 OR lt DATSVCLL DAHeat Space HighCO2 P AND ye 4 HeatPl SatLow 7 A AND 4 PATVELL HeatPI SatHi 2min N AND DAT lt VCLL LLPIESatLow 2min AND 3 minutes OR DAT gt VCLL 1 8F 7 LowLimit Econ Available Econ Available N es 4 NU gt N MechCool Available N Econ Available N N MechCool Available Na Econ State State 3 The Econ state is a normal state during Cool mode The Econ state typically is active in the Cool mode when primary cooling economizer is available and adequate to meet the cooling requirements When the Econ state becomes active the UVC uses economizer cooling see Economizer Operation on page 32 as needed to maintain the effective cooling set point see Space Temperature Set Points on page 26 If cooling is not required while in the Econ state the UVC can idle in the Econ state until cooling is required or until there is a call to switch to another mode or state The UVC monitors the DAT to ensure it does not fall below VCLL The CO demand controlled ventilation function optional will be active see CO2 Demand Controlled Ventilation optional on page 34 and the OA damper is adjusted as needed to maintain the CO set point McQuay OM 751 19 Description of Operation
27. Economizer Strategy 1 e Leading Edge optional Temperature Comparison with Enthalpy Comparison Economizer Strategy 2 Temperature Comparison Economizer default If the default Basic economizer function is selected the unit ventilator is provided from the factory without the optional IA and OA humidity sensors In this case the UVC is factory set for Economizer Strategy 1 the UVC automatically detects that no OA humidity sensor is present and adjusts to use the Temperature Comparison Economizer function Temperature Comparison with OA Enthalpy Setpoint Economizer optional If the optional Expanded economizer function is selected the unit ventilator is provided from the factory with the optional OA humidity sensor which is used along with the OA temperature sensor to calculate OA enthalpy In this case the UVC is factory set for Economizer Strategy 1 and uses the Temperature Comparison with OA Enthalpy Setpoint Economizer function Note Temperature Comparison with OA Enthalpy Setpoint Economizer requires an optional OA humidity sensor Temperature Comparison with Enthalpy Comparison Economizer optional If the optional Leading Edge economizer function is selected the unit ventilator is provided from the factory with both the IA humidity and OA humidity sensors which are used along with the IA temperature and OA temperature sensors to calculate IA enthalpy and OA enthalpy In this case the UVC is factory set for Economize
28. FE 16 Change Filter Indication Manual FF 17 EPROM Memory Indicator Replace conroller board EE 18 Configuration Display Download file ta Rev 1_27 has auto reset McQuay OM 751 41 Diagnostics and Service Space Temp Sensor Failure FQ The Space Temp Sensor Failure fault occurs when the UVC detects open or short conditions from the sensor Effect e Space fan de energizes unless in emergency heat mode e Compressor immediately de energizes e Outdoor fan if present de energizes e Outside air damper is forced closed e Electric heat stages are de energized e Fault is indicated DX Pressure Fault F The DX Pressure Fault occurs when the UVC detects a switch open condition from the refrigerant pressure switch Effect e Compressor immediately de energizes e Outdoor fan if present de energizes e Fault is indicated Compressor Envelope Fault Fc The UVC monitors refrigerant temperatures The Compressor Envelope Fault occurs when the UVC detects compressor operation that exceeded the allowed operating parameters Effect e Compressor immediately de energizes e Outdoor fan if present de energizes e Fault is indicated Cause e Poor air or water flow through the refrigerant coils Check fans for proper rpm Check air filters e If the unit has a three phase scroll compressor check for proper electrical phasing e Refrigerant circuit component failure or improper adjustment Check re
29. Introduction Introduction This manual provides information on the MicroTech II control system used in the AAF HermanNelson Unit Ventilator product line It describes the MicroTech II components input output configurations field wiring options and requirements and service procedures For installation and general information on the MicroTech II Unit Ventilator Controller refer to IM 747 MicroTech II Unit Ventilator Controller For installation commissioning instructions and general information on a particular unit ventilator model refer to the appropriate manual Table 1 as well as accompanying software operating instruction manual Table 4 and possible accessory manuals that may pertain to the unit Table 3 For installation and maintenance instructions on a plug in communications card refer to the appropriate protocol specific installation and maintenance manual Table 2 For a description of supported network variables for each protocol refer to Protocol Data Packet bulletin ED 15065 Table 1 Model specific unit ventilator installation literature Description Manual B52 55555525859898ZZ Air Source Heat Pump IM 502 X DDC Control Components AED Q MTII 811 X Self Contained IM 503 X X X X X X Self Contained DDC AZS QVURMII X X X X X Control Components 810 Vertical Split system IM 817 1 X X X X Horizontal Split system IM 830 X X X X X X X X Ceiling Vent AH IM 830 X X X X
30. OccupancyMode Occupied or BypassHeat CoolMode Heat SpaceTempSetpoint 71 0 F SetpointOffset 1 0 F occupant adjustment on remote wall sensor or LUI SetpointShift not used 0 0 F OCS 73 4 F OHS 69 8F Effective set point calculations AbsoluteOffset OCS OHS 2 73 4 F 69 8 F 2 1 8 F EffectiveSetpoint SpaceTempSetpoint AbsoluteOffset SetpointOffset SetpointShift 71 0 1 0 1 0 0 0 68 2 F Example A Example B 28 McQuay OM 751 Description of Operation Proportional Integral PI Control Loops The MicroTech II UVC uses PI loop control for heating cooling and ventilation processes within the unit ventilator Numerous PI algorithms can be used depending upon the unit ventilator configuration The UVC uses single and cascading PI loops where needed Table 16 PI loop list Feedback PI loops PI loop type Set point controlled Output variable Effective Heating or Cooling Calculated Discharge Air EP Space Temperature Temperature Setpoint Space lemperat re Temperature Setpoint Output PI 2 Primary Cooling Economizer Calculated Discharge Alr Temperature Discharge Air Position the OA Damper ai Setpoint Output Temperature f ascading Calculated Discharge Air Temperature Discharge Air PI 3 Secondary Cooling Setpoint Output Temperature Operate the Compressor PI 4 Braman Heatin Calculated Discha
31. Point Calculations The UVC calculates the effective set point Effective Set Point Output based on several factors These factors include the six occupancy set points for heating and cooling Occupancy Temperature Set Point occupancy mode the value of the network variables Space Temp Set Point Input Set Point Offset Input and the Set Point Shift Input as well as the optional wall mounted sensor s set point adjustment knob As always network inputs have priority over hardwired connections The UVC determines if heating or cooling is required based on the current unit mode Heat Cool Mode Output and then calculates the required set point for heating or cooling After calculating the Effective Set Point Output network variable is set equal to the calculated set point The Effective Set Point Output is the temperature set point that the UVC maintains which normally appears on the keypad display McQuay OM 751 27 Description of Operation Figure 16 Effective set point calculations Occupancy Temperature Setpoints network configuration variables Effective Set Point Calculations for each Occupancy Mode Occupied Cooling Set Point OCS Standby Cooling Set Point SCS Unoccupied Cooling Set Point UCS AbsOffsetOccupied Setpoint OCS OHS 2 Occupied Heating Set Point OHS AbsOfisetStandby Setpoint SCS SHS 2 Standby Heating Set Point SHS Unoccupied Heating Set Point UHS Occupied and Bypass Modes Eff
32. Step 2 determine the expected sensor voltage from Table 24 4 Using a calibrated multi meter measure the actual voltage across the yellow and white sensor leads Wire color definitions White ground Yellow output VDC Blue supply VDC 5 Compare the expected voltage to the actual voltage 6 Ifthe actual voltage value deviates substantially more than 10 from the expected voltage replace the sensor McQuay OM 751 45 Diagnostics and Service Table 24 Humidity versus voltage RH VDC mV RH VDC mV 10 1330 55 2480 15 1475 60 2600 20 1610 65 2730 25 1740 70 2860 30 1870 75 2980 35 1995 80 3115 40 2120 85 3250 45 2235 90 3390 50 2360 95 3530 Troubleshooting Carbon Dioxide CO Sensors The UVC is configured to use a 0 2000 PPM 0 10 VDC single beam absorption infrared gas sensor Each sensor is calibrated according to the table shown Use the following procedure to troubleshoot a suspect sensor Disconnect the sensors output voltage lead from the UVC analog input xAI 3 Using some other calibrated CO sensing device take a CO reading at the sensor location 1 2 3 Use the CO reading from Step 2 to determine the expected sensor voltage from Table 25 4 Using a calibrated multi meter measure the actual voltage across the lead removed from xAI 3 and ground a Compare the expected voltage to the actual voltage 6 Ifthe actual voltage value
33. V relay for verification To verify 1 Puta relay across the Triac outputs 2 Cycle the power 3 Verify the relay s closed contacts during calibration Minimum Position The UVC ss configured to maintain three OA damper minimum positions based on the operation of the IAF fan This allows each unit to be field configured to provide the amount of fresh air required to the space at each of the three IA fan speeds Table 17 Default OA damper minimum positions IAF speed Without CO With CO High 20 5 Medium 25 5 Low 30 5 Note If the CO Demand Controlled Ventilation DCV option is used the UVC only uses the IA fan high speed OA damper minimum position regardless of fan speed The DCV function adjusts the OA damper above this minimum as needed to maintain CO set point Economizer Operation The economizer function is used by the UVC to determine if the OA is adequate for economizer primary cooling When both the economizer and mechanical cooling are available the economizer is used as primary cooling and the UVC adds mechanical cooling only if the economizer is not adequate to meet the current cooling load e g the OA damper reaches 100 and cooling is still required The UVC supports three economizer functions e Basic default Temperature Comparison Economizer 32 McQuay OM 751 Description of Operation e Expanded optional Temperature Comparison with OA Enthalpy Setpoint
34. ailure fault occurs when the UVC detects open or short conditions from the sensor Emergency heat mode is available during this fault condition Effect e Space fan is immediately de energized unless in emergency heat mode e Outside air damper is forced closed e Electric heat stages are de energized e Compressor immediately de energizes e Outdoor fan if present immediately de energizes e Fault is indicated Outdoor Coil DX Temp Sensor Failure FB The Outdoor Coil DX Temp Sensor Failure fault occurs when the UVC detects open or short conditions from the sensor Effect e Compressor immediately de energizes e Outdoor fan if present de energizes e Fault is indicated McQuay OM 751 43 Diagnostics and Service Space Humidity Sensor Failure optional FA The Space Humidity Sensor Failure fault occurs when the UVC detects open or short conditions from the sensor Effect e IA OA Enthalpy comparison economizer if used is disabled e Dehumidification function optional is disabled e Fault is indicated Outdoor Humidity Sensor Failure optional Fb The Outdoor Humidity Sensor Failure fault occurs when the UVC detects open or short conditions from the sensor Effect e IA OA Enthalpy comparison or OA Enthalpy economizer if used is disabled e Fault is indicated Space CO Sensor Failure optional FC The Space CO Sensor Failure fault occurs when the UVC detects open or short condition
35. ao Satisfied e _______ Warmer Mech State State 2 The Mech state is a normal state during Cool mode The Mech state typically is active in the Cool mode when primary cooling economizer is not available and secondary cooling compressor is available When the Mech state becomes active the UVC uses the unit s mechanical cooling capabilities as needed to maintain the effective cooling set point see Space Temperature Set Points on page 26 If cooling is not required while in the Mech state the UVC can idle in the Mech state until cooling is required or until there is a call to switch to another mode or state The UVC monitors the DAT to ensure it does not fall below MCLL 20 McQuay OM 751 Description of Operation The CO demand controlled ventilation function optional is active see CO2 Demand Controlled Ventilation optional on page 34 and the OA damper is adjusted as needed to maintain the CO set point Figure 15 Mech state operation occupied mode and auto fan OA Damper 20 Open O IA Fan High Speed P Staging Compressor On p Up 4 OA Damper 30 Open A IA Fan Medium Speed 4 Osawi Compressor On PP 7 7 i vy Staging Down OA Damper 35 Open IA Fan Low Speed lt q gt Compressor On r EAE i OA Damper 35 Open Yv Secondary IA Fan Low Speed 7 Coolin Copmressor Off gm a EE gt g 32 o s g ggg S 5 HR a
36. ay local user interface The following sections describe how to use the keypad display Note Many UVC parameters are accessible both through the keypad display and the network interface The shared keypad display and the network interface variables have a last change wins relationship Using the Keypad Display The keypad display shown in Figure 1 is provided with all MicroTech II Applied Unit Ventilator unit controllers With the keypad display operating conditions system alarms and control parameters can be monitored Set points and other parameters also can be modified Figure 1 Keypad display MicroTech II FAN ONLY HIGH A v COOL MED HEAT Low FUNC AUTO AUTO ON Display Format The keypad display s 2 digit 7 segment display normally shows the effective heating or cooling temperature set point Effective Set Point Output The display also is used to view and modify UVC parameters as explained in the following sections Note When the UVC is in the OFF mode the effective heating set point appears in the display All other LEDs are switched off Keypad Functions Security Levels The keypad display provides a 4 level password security feature that can be used to restrict access The available security levels are shown in Table 6 Note All unit ventilator controllers ship with the lowest security level 0 enabled To change security levels see Figure 2 Once a security level is changed the
37. cQuay Representative for warranty details Refer to Form 933 43285Y To find your local McQuay Representative go to www mcquay com This document contains the most current product information as of this printing For the most up to date product information please go to www mcquay com McQuay Air Conditioning 2006 McQuay International e www mcquay com 800 432 1342
38. ccupancy levels This type of fixed damper control for ventilation is energy wasteful since you are treating OA not actually needed for ventilation during low occupancy levels People produce CO when they breath the CO level within the space has a direct relationship with the number of people within that space The UVC can optionally be factory configured to provide CO based Demand Controlled Ventilation DCV The CO DCV function is useful in saving the energy typically wasted in treating OA not actually needed for ventilation within a space during occupancy levels below maximum design The CO DCV function uses a PI loop control to adjust the OA damper above the minimum position as needed to maintain the Space CO Setpoint 1200 PPM default The minimum damper position used with CO DCV typically can be set at 20 of the minimum position that would be used without CO DCV For example if the minimum OA damper position typically is 20 then when using CO DCV you could set the new minimum OA damper position as low as 4 e g 20 x 0 20 4 This new smaller minimum OA damper position then should provide enough ventilation to keep odors in check within the space for most applications Note The CO DCV function can increase the OA damper position past that required by the economizer and vice versa If odors within the space become a problem increase the OA damper minimum position as needed to eliminate these odors It may be ne
39. cessary with new construction or after renovation to raise the minimum position for some time period to help reduce odor build up due to the out gassing of new construction material and then return the minimum OA damper position at a later date If the CO Demand Controlled Ventilation DCV option is used the UVC only uses the IA fan high speed OA damper minimum position regardless of fan speed The DCV function adjusts the OA damper above this minimum as needed In this case the IA fan high speed OA damper minimum position is factory set at 5 Networked Space CO Sensor Capability A networked space CO sensor can be network interfaced with the Space CO Input variable When the Space CO Input variable is used valid value it automatically overrides the hard wired space CO sensor if present 34 McQuay OM 751 Description of Operation ASHRAE Cycle Il The UVC supports ASHRAE Cycle II operation The basis of ASHRAE Cycle II is to maintain the required minimum amount of ventilation whenever possible which can be increased during normal operation for economizer cooling or CO DCV control or reduced to prevent excessively cold discharge air temperatures A discharge air temperature sensor is installed in all unit ventilators If necessary the ASHRAE II control algorithm overrides room control and modifies the heating ventilating and cooling functions as available to prevent the discharge air temperature from falling bel
40. ctive ra rak Heat PI Sat Hi 5 N 4 2 minutes AND DAT lt VCLL LLP Sat Lo Cant Heat 2 minutes AND B NG DATS VCLL 1 8F N 1 ra Heat Available Heat Available Low Limit Inactive jp Heat State State 5 The Heat state is the normal state during Heat mode When the Heat state becomes active the UVC will within State continually calculate the DATS Discharge Air Temperature Control on page 29 required to maintain the effective heat setpoint see Space Temperature Set Points on page 26 The calculated DATS will not be allowed to go above DAHL The UVC will use auxiliary heat if field provided and field connected to the unit as needed to maintain the current DATS The auxiliary heat binary output will be used as needed The Heat Timer 3 minutes fixed will begin counting The CO demand controlled ventilation function will be active if the unit is equipped for CO control see CO2 Demand Controlled Ventilation optional on page 34 and the OA damper will be adjusted as needed to maintain the CO setpoint The UVC will remain in this state until one of the transition out conditions become true or until one of the super state transition out conditions becomes true McQuay OM 751 17 Description of Operation Note The OAD is considered to be in alarm when the OAD is forced below the active minimum position in the Low Limit state This is not an act
41. d affects IAF operation and affects OAD operation The Manual Adjust Occupancy and Networked Occupancy Sensor network variables along with the Unoccupied and Tenant Override binary inputs are used to determine the Effective Occupancy The term Don t care in Table 12 implies that another network variable or binary input to the left has a higher priority Note The Occupancy Override Input is provided as a way for a network connection to manually force the UVC into a particular occupancy mode The Occupancy Override Input can override the tenant override feature For example if the network uses the Occupancy Override Input to force the unit into unoccupied mode then the tenant override switch does not operate as expected Therefore McQuay strongly recommends using the Occupancy Sensor Input to control occupancy modes over a network and only using the Occupancy Override Input if there is reason to ensure tenant override does not occur Table 12 Occupancy mode priority Priority result Network input Network output WN into bypass Occupied Mode Typical operation is defined in this row of the table The tenant override switch unit or wall sensor mounted can be used here to force the UVC Effective Occupancy Occupancy BR E 4 Unoccupied binary input occupancy Override input sensor input 2 output Occupied Don t care Don t care Occupied Unoccupied Don t care
42. e OFF mode the effective heating set point appears in the display All other LEDs are switched off The UVC archives each change to the keypad display FAN and MODE keys When the ON STOP key is used to bring the unit out of OFF mode the UVC implements the last active fan and unit modes Each time the UVC power cycles the UVC is in the auto fan and auto unit modes when power is returned VAN WARNING Off mode is a stop state for the unit ventilator It is not a power off state Power may still be provided to the unit FAN Key Use the FAN key to toggle through each of the fan speeds Fan Speed Command Input Auto Low Medium and High MODE Key Use the MODE key to toggle through the keypad display accessible unit modes Heat Cool Mode Input Auto Heat Cool and Fan Only Arrow Keys Use the arrow keys to scroll between parameters and to adjust parameters FUNC Key Use the Func key to view the actual space temperature or to confirm selection and changes to user adjustable parameters McQuay OM 751 Getting Started Using the Keypad Display Viewing Actual Indoor Air Temperature IAT Normally the effective set point temperature appears on the keypad display You also can use the keypad display to view the indoor air temperature IAT See Figure 3 Note When the actual indoor air temperature Effective Space Temp Output equals the effective set point temperature Effective Set Point Out
43. e UVC Alarm and Fault Monitoring The UVC is programmed to monitor the unit for specific alarm conditions If an alarm condition exists a fault occurs When a fault exists the following occurs e The UVC indicates the fault condition by displaying the fault code on the keypad display e The remote wall mounted sensor optional LED flashes a pattern indicating that a fault condition exists e The fault signal binary output energizes e The fault performs the appropriate control actions as described for each fault Manual reset faults can be reset in one of three ways e By cycling the unit power e Via the keypad display menu e Via the network interface Table 22 Alarm and fault code summary Keypad Priority Fault description Reset display fault codes 1 Space Temp Sensor Failure Auto FO 2 DX Pressure Fault 2 Auto in 7 days then Manual Fi 3 Compressor Envelope Fault 2 Auto in 7 days then Fa Manual 4 Discharge Air DX Cooling Low Limit Indication Auto FA 5 Condensate Overflow Indication Auto FY 6 Space Coil DX Temp Sensor Failure Auto FS 7 Outdoor Temp Sensor Failure Auto F6 8 Discharge Air Temp Sensor Failure Auto Fi 9 Water Coil DX Temp Sensor Failure Auto FB 10 Water out Temp Sensor Failure Auto FQ 11 Space Humidity Sensor Failure Auto FA 12 Outdoor Humidity Sensor Failure Auto Fb 13 Space CO Sensor Failure Auto E 14 Not used Fd 15 Not used
44. e the Effective Set point Output The effective set point is calculated based on the unit mode the occupancy mode and the values of several network variables The effective set point then is used as the temperature set point that the UVC maintains Table 14 Default occupancy based temperature set points Temperature set point Abbreviation Defaults Unoccupied cool UCS 82 4 F 28 0 C Standby cool SCS 77 0 F 25 0 C Occupied cool OCS 73 4 F 23 0 C Occupied heat OHS 69 8 F 21 0 C Standby heat SHS 66 2 F 19 0 C Unoccupied heat UHS 60 8 F 16 0 C Networked Set Point Capability The Space Temp Setpoint Input variable is used to allow the temperature set points for the occupied and standby modes to be changed via the network the unoccupied set points are not affected by this variable Networked Set Point Offset Capability The Networked Set Point Offset Input variable is used to shift the effective occupied and standby temperature set points by adding the value of the Setpoint Offset Input variable to the current set points the unoccupied points are not affected by this variable This variable is typically set bound to a supervisory network controller or to a networked wall module having a relative set point knob Use the keypad display to make adjustments to the value of the Setpoint Offset Input variable See Changing Set Points on page 9 Note The keypad display and the net
45. economizer cooling is available McQuay OM 751 35 Description of Operation Compressor Minimum On and Off Timers The UVC is provided with minimum On 3 minute default and minimum Off 5 minute default timers to prevent adverse compressor cycling Compressor Start Delay The UVC is provided with a Compressor Start Delay configuration variable which is intended to be adjusted as part of the start up procedure for each unit This variable is used to delay compressor operation each time the compressor is required Note To prevent strain on a building s electrical supply system from multiple unit compressors all starting at the same time after a power failure or after an unoccupied to occupied changeover McQuay strongly recommends configuring each unit or groups of units at start up with different start delays Outdoor Air Fan Operation The UVC is configured with a fan on delay that delays OA fan operation for a time period 10 seconds default after the compressor starts The OA fan stops with the compressor Floating Point Actuator Auto Zero Overdrive and Sync The UVC at power up auto zeros all floating point actuators OA damper before going into normal operation to ensure proper positioning During auto zero the unit remains off The actuators all open approximately 30 and then are driven full closed The overdrive feature then is used to continue forcing the actuators closed for one full stroke period Once the z
46. ectiveCoolSetpoint OCS AbsOffsetOccupied SetptOffset OCSS EffectiveHeatSetpoint OHS AbsOffsetOccupied SetptOffset OHSS Space Temp Set Point Input Network Value network input Set Point P 55 F 85 F Wall Sensor Standby Mode N WallSensorType K EffectiveCoolSetpoint SCS AbsOffsetStandby SetptOffset SCSS vee SO ae EffectiveHeatSetpoint SHS AbsOffsetStandby SetptOffset SHSS Wall Sensor Unoccupied Mode Local User EffectiveCoolSetpoint UCS UCSS Set Point 5 F 5 F SetptOffset gt EffectiveHeatSetpoint UHS UHSS Offset Input Network Value network input SetptShift network inputs Occupied Cooling Set Point Shift OCSS Standby Cooling Set Point Shift SCSS Unoccupied Cooling Set Point Shift UCSS If both entering paths have Occupied Heating Set Point Shift OCSS valid values then the keypad display value Standby Heating Set Point Shift HSS has priority If both entering paths have valid values then the network value has priority Unoccupied Heating Set Point Shift UHSS Table 15 Set point calculation examples Given OccupancyMode Occupied or BypassHeat CoolMode Heat SpaceTempSetpoint not used SetpointOffset not used 0 0 F SetpointShift not used 0 0 F OHS 69 8 F Effective set point calculations EffectiveSetpoint OHS SetpointOffset SetpointShift 69 8 0 0 0 0 69 8 F Given
47. eroing process is complete normal unit operation begins The UVC is configured such that whenever a floating point actuator is commanded to go to 0 or 100 the UVC overdrives the actuator one full stroke period past the 0 or 100 position to ensure proper positioning Additionally the UVC is configured to sync all floating point actuators once every six hours of operation To do this the UVC forces the actuator to the closest rail position 0 or 100 uses the overdrive feature and then returns to the required position For example if the actuator is at 20 when the six hour limit is reached the UVC then forces the actuator to 0 overdrive for one full stroke and then returns to the 20 position 36 McQuay OM 751 Description of Operation External Binary Inputs The UVC is provided with three binary inputs that provide the functions described below Figure 24 Binary inputs Binary Inputs 3 sets of dry contacts to signal UVC Input 1 Unoccupied default Input 2 Remote shutdown gt Input 3 Ventilation lockout default or Exhaust interlock system These inputs each allow a single set of dry contacts to be used as a signal to the UVC Multiple units can be connected to a single set of dry contacts For wiring examples see MicroTech II Unit Ventilator Controller IM 747 Note Not all of the functions listed can be used at the same time The UVC is provided with configuration paramet
48. ers that can be adjusted to select which function is used for these inputs where multiple functions are indicated below External Binary Input 1 This input can be configured as an unoccupied default or dew point humidity signal Unoccupied Input Signal This input allows a single set of dry contacts to be used to signal the UVC to go into unoccupied or occupied mode When the contacts close the UVC goes into unoccupied mode When the contacts open the UVC goes into occupied mode Additional variables can effect occupancy mode and override this binary input See Occupancy Modes on page 24 External Binary Input 2 This input can only be used for remote shutdown Remote Shutdown Input Signal This input allows a single set of dry contacts to be used to signal the UVC to go into shutdown mode When the contacts close shutdown the UVC goes into shutdown mode When the contacts open the UVC returns to normal operation See Special Purpose Unit Modes on page 21 External Binary Input 3 This input can be configured as a ventilation lockout default or exhaust interlock signal Ventilation Lockout Input Signal This input allows a single set of dry contacts to be used to signal the UVC to close the OA damper When the contacts close ventilation lockout signal the UVC closes the OA damper When the contacts open the UVC returns to normal OA damper operation McQuay OM 751 37 Description of Operation Exhaust
49. for the correction thereof VAN WARNING Electric shock hazard Can cause personal injury or equipment damage This equipment must be properly grounded Connections and service to the MicroTech II control panel must be performed only by personnel that are knowledgeable in the operation of the equipment being controlled VAN CAUTION Extreme temperature can damage system components The MicroTech Il controller is designed to operate in ambient temperatures from 20 F to 125 F It can be stored in ambient temperatures from 40 F to 140 F It is designed to be stored and operated in relative humidity up to 95 non condensing Z N CAUTION Static sensitive components A static discharge while handling electronic circuit boards can damage components Discharge any static electrical charge by touching the bare metal inside the main control panel before performing any service work Never unplug any cables circuit board terminal blocks relay modules or power plugs while power is applied to the panel McQuay OM 751 Introduction Acronyms Abbreviations The following table list acronyms and abbreviations that may or may not be used within this manual Other abbreviations for keypad displays and parameters can be found in Table 8 on page 14 and Table 26 on page 47 Table 5 Acronyms and abbreviations ee Acronym
50. frigerant pressures and TXV adjustment e Coil sensors may have lost proper contact with the refrigerant coil Check coil sensors Discharge Air DX Cooling Low Limit Indication F3 The Discharge Air DX Cooling Low Limit Indication fault occurs when the UVC detects a low discharge air temperature DAT lt MCLL during compressor cooling Effect e Compressor immediately de energizes e Outdoor fan if present de energizes e Fault is indicated on earlier software versions 42 McQuay OM 751 Diagnostics and Service Condensate Overflow Indication optional F4 The Condensate Overflow Indication fault will occur when the UVC detects high condensate levels within the units indoor coil drain pan Effect e Compressor is immediately de energized if in cooling e Outdoor fan if present is de energized e Fault is indicated Space Coil DX Temp Sensor Failure F5 The Space Coil DX Temp Sensor Failure fault occurs when the UVC detects open or short conditions from the sensor Effect e Compressor immediately de energizes e Outdoor fan if present de energizes e Fault is indicated Outdoor Temp Sensor Failure F5 The Outdoor Temp Sensor Failure fault occurs when the UVC detects open or short conditions from the sensor Effect e Outside air damper is forced closed e Compressor immediately de energizes e Fault is indicated Discharge Air Temp Sensor Failure F1 The Discharge Air Temp Sensor F
51. hen in Depressurize mode the UVC will use the IAF OAD and exhaust output as needed to depressurize the space The UVC stops all normal heating and cooling but does allow emergency heat if required The de pressurize mode can only be accessed via a network connection or with ServiceTools for MicroTech II Applied Terminal Unit Controllers ATS Purge Mode When in Purge mode the UVC uses the IAF OAD and exhaust output as needed to purge the space The UVC stops all normal heating and cooling but does allow emergency heat if required The purge mode can only be accessed via a network connection or with ServiceTools for MicroTech II Applied Terminal Unit Controllers ATS Shutdown Mode Shutdown mode is the equivalent of the Off mode but is an Off mode forced by a network connection When in Shutdown mode the UVC stops all normal heating cooling ventilation OA damper is closed and fan operation By default emergency heat is not be used during the shutdown mode however the UVC can be configured Emergency Heat Shutdown Configuration to allow emergency heat operation during shutdown mode The shutdown mode can be accessed via a network connection a binary input to the UVC or with ServiceTools for MicroTech II Applied Terminal Unit Controllers ATS VAN WARNING Shutdown mode and energy hold off mode are a stop state for the unit ventilator It is not a power off state Energy Hold Off Mode The UVC supports an e
52. ith no OAD Economizer Enable 0 disable 1 enable 4 El Economizer OA Temp Setpoint ETS 68 F 20 C Fe Economizer IA OA Temp Differential ETD 2 F 1 C EJ Economizer OA Enthalpy Setpoint EES 25 btu lb 58 kJ kg E5 Economizer IA OA Enthalpy Differential EEp 1 3 btu lb 3 kJ kg FA External BI 3 Configuration 0 Ventilation Lockout 1 Exhaust Interlock 0 hi External BO 3 Configuration 0 Exhaust Fan On Off 1 Auxiliary Heat 0 bo Filter Alarm Enable 0 disable 1 enable 0 CE Filter Change Hours Setpoint fan run hours between filter change alarms 700 hrs McQuay OM 751 47 UVC Configuration Parameters Primary Cool Proportional Band 18 F 10 C Primary Cool Integral Time 180 sec Secondary Cool Proportional Band 18 F 10 C Secondary Cool Integral Time 600 sec Discharge Air Temp Proportional Band 4 F 2 22 C Discharge Air Temp Integral Time 300 sec CO Proportional Band 100 PPM CO Integral Time 600 sec Ventilation Cooling Low Limit Setpoint ye discharge air low limit during ventilation or economizer cooling 54 F 12 C de Mechanical Cooling Low Limit Setpoint mcp discharge air low limit during mechanical compressor cooling 45 F 7 C di Discharge Air High Limit DAHL 140 F 60 C Space Fan Off Delay 30 sec Fan Cycling Configuration space fan operation during occupied standby and bypass 2 re occupancy modes 2
53. izer IA OA i a a 1 3 Btu lb EB Enthalpy Differential EED Adjust economizer IA OA enthalpy differential RW x 3 kJ kg ri Space Humidity Output ERH Display room humidity optional 00 No sensor connected RO x r J rere Air Humidity EORH Display OA humidity optional 00 No sensor connected RO x ot Outdoor Air Temp Output EOAT Display OA temperature RO x Hi Emergency Heat Enable Set emergency heat status 0 disable 1 enable RW x 1 Emergency Heat Set F F 53 6 F He point EHS Adjust emergency heat set point RW x 12 C HI Emergency Heat Set emergency heat operation during shutdown 0 no emergency heat during Rw x 0 Shutdown Configuration shutdown 1 allow emergency heat during shutdown Ai Auxa HeatStart AHSD Adjust auxiliary heat start differential Rw x 4 8 F 1 C Differential X Auxiliary Heat End Mm H sising Ad Differential AHED Adjust auxiliary heat stop differential RW x 1 8 F 1 C Ag Avxiliary Heat Set auxiliary heat type 0 N O device 1 N C device RW x 0 Configuration ba xternal BI et the function external binary Input 3 0 ventilation lockout 1 exhaus bi Ext BI 3 Set the functi t bi Input 3 0 tilation lockout 1 haust RW x 0 Configuration interlock xterna et the function of external binary output 3 0 exhaust fan on off signal 1 b6 Ext BO 3 Set the functi f ext bi tput 3 0 haust f off signal 1 RW x 0 Configuration auxiliary heat re Fan C
54. m list Abr Description Rw Default rA Reset Alarm Input Enter 1 to clear alarms clears all inactive alarms except filter alarm To enable RW x HIT the alarm again enter 0 rm UVC Heat Cool Mode Display current UVC mode 1 Heat 3 Cool 4 Night Purge 6 Off 8 Emerg HL Output UNEM Heat 9 Fan Only RO X UVC State Output Display current UVC state 1 EconMech 2 Mech 3 Econ 4 DA Heat 5 S UVCS Heat 6 ActiveDehum 7 Full Heat 8 Night Purge 9 Off 10 Fan Only 11 RO x Heat Mode Cant Heat 12 CantCool 13 Emerg Heat Mode Cant Heat 14 Heat Mode Low Limit 15 Cool Mode Low Limit di ae itd gmp Set DATS Display current DA temperature set point RO x d bar Air Temp DAT Display current DA temperature RO x de noe Low VCLL Adjust economizer cooling DA temperature low limit RW x NEA d3 Meehanical Cooling Low MCLL Adjust mechanical cooling DA temperature low limit RW x a r Limit set point 7 C Slave Type Configuration Set slave type 0 Independent slave uses own sensors 1 Dependent slave bi follows master This feature requires a network over which the master and slave RW x 0 UVCs can communicate E o Effective Occupancy Display current occupanc RO x Output p ay nee Occupancy Override Set occupancy 0 occupied 1 unoccupied 2 bypass 3 standby Adjusting r OL Input this variable is intended only for troubleshooting Once you are done cycle unit RW x r2 power
55. midification a RDS sequences S0 Rh Emergency Heat Enable 0 disable 1 enable uses auxiliary heat where primary heat is 4 H not applicable Emergency Heat Setpoint EHS 54 F 12 C He Emergency Heat Shutdown 0 no emergency heat during shutdown 1 emergency heat 0 HI Configuration available during shutdown Wall Sensor Type 0 3 F 1 55 F to 85 F 0 r5 Slave Type Configuration 0 independent slave 1 dependent slave 0 L OAD Min Position High Speed Setpoint this variable will be factory set to 5 open when the unit is ordered d OADH With optional CO DCV 20 open oc OAD Min Position Med Speed Setpoint OADM we aan is ignored when the unit is ordered with optional CO3 25 open 23 OAD Min Position Low Speed Setpoint OADL this variable is ignored when the unit is ordered with optional CO2 30 open 54 DCV Exhaust Interlock OAD Min Position EOAD OA damper minimum position when the exhaust interlock input is 99 open NG Setpoint energized Energize Exhaust Fan OAD Setpoint oape defines position above which exhaust fan output will be energized 12 open of OAD Max Position Setpoint OAMX 99 open al OAD Lockout Enable 0 disable 1 enable this variable will be factory set to 1 when 0 g the unit is ordered as a recirc unit with no OAD o OAD Lockout Setpoint OA temperature below which the OA damper will remain closed OALS this variable will be factory set to 99 C when the unit is ordered 36 F 2 C n9 as a recirc unit w
56. mp ES a N N O DS Satisfied Warmer Discharge Air DA Heat State State 4 The DA Heat state is a normal state during Cool mode The DA Heat state typically is active when reheat is required to maintain DATS while maintaining the required OA damper position The DA Heat state can also be made active if the optional CO DCV feature is provided and CO levels are high requiring the OA damper to open beyond what is required for economizer cooling When DA Heat state is active the UVC uses the units heating capability as needed to maintain VCLL The CO demand controlled ventilation function optional is active see CO2 Demand Controlled Ventilation optional on page 34 and the OA damper is adjusted as needed to maintain the CO set point Low Limit State State F The Low Limit state is a non normal state during Cool mode The Low Limit state typically follows the DA Heat state when the UVC reaches 100 heat and still cannot maintain VCLL When the Low Limit state becomes active the Low Limit PI loop overrides the OAD minimum position see Outdoor Air Damper Operation on page 32 and adjusts the OAD toward closed as necessary to maintain the DAT set point see Discharge Air Temperature Control on page 29 Cant Cool State State C The Cant Cool state is a non normal state during Cool mode The Cant Cool state typically becomes active when both primary economizer and secondary compressor
57. mpers OAD Energize Exhaust Fan OAD Setpoint OADE OAD Min Position High Speed Setpoint OADH OAD Min Position Low Speed Setpoint OADL OAD Min Position Med Speed Setpoint OADM Outdoor Air Damper Position OADP OAD Lockout Setpoint OALS OAD Max Position Setpoint OAMX Outside Air Temperature OAT McQuay OM 751 5 Introduction Description Acronym Abr Occupied Cooling Setpoint OCS Occupied Heating Setpoint OHS Occupancy Override Input OOl Occupancy Sensor Input OSI Proportional Integral PI Parts Per Million PPM Positive Temperature Coefficient PTC Relative Humidity RH Space Humidity Setpoint RHS Read Only RO Read Write RW Standby Cooling Setpoint scs Standby Heating Setpoint SHS Thermal Expansion Valve TXV Unoccupied Cooling Setpoint UCS Unoccupied Heating Setpoint UHS Unit Ventilator UV Unit Ventilator Controller UVC UVC Heat Cool Mode Output UVCM UVC State Output UVCS Wet Heat Valve Position VALP Ventilation Cooling Low Limit Setpoint VCLL Ventilation Cooling Lockout VCLO Ventilation Cooling Setpoint VCS Wet Heat WH Source water in Temperature Differential WITD McQuay OM 751 Getting Started Getting Started The MicroTech II Unit Vent Controller UVC is a self contained device that is capable of complete stand alone operation Information in the controller can be displayed and modified by using the keypad displ
58. nergy hold off state which when active forces the UVC to stop all normal heating cooling and ventilation Typically used by a network connection to force the UVC to cease heating cooling and ventilation when conditions exist where heating cooling and ventilation are not required or desired Energy hold off mode is very similar to shutdown mode except that energy hold off always allows emergency heat if required The energy hold off mode can only be accessed via a network connection or with ServiceTools for MicroTech II Applied Terminal Unit Controllers ATS 22 McQuay OM 751 Description of Operation Unit Mode Priority The UVC uses the network variables and binary inputs listed in Table 10 and Table 11 to determine the current unit mode Special purpose UVC unit modes have higher priority than the normal UVC unit modes as shown in the tables Each table lists the highest priority items on the left to the lower priority items to the right The right most columns indicate unit operation as a result of the left most columns The term Don t care in these tables implies that another network variable or binary input to the left has a higher priority Table 10 Special purpose UVC unit mode priority Priority result Emergency ovemide Remote shutdown Energy hold Energy hold Unit mode Actual UVC action input binary input off input off output output 4 Normal Normal e the honral 3 De energized UVC mode p
59. o mode is provided so that the UVC can be set to automatically determine if heating or cooling is required Auto mode is the default power up UVC mode Auto mode is made up of the Heat and Cool modes When the UVC is set to auto mode the UVC automatically determines which mode Heat or Cool to use Heat Mode Super State When in Heat mode the UVC will use auxiliary heat if field provided and field connected to the unit as needed to maintain the effective heating setpoint see Space Temperature Set Points on page 26 The keypad display or a network connection can be used to force the unit into the Heat mode Additionally the UVC when set to Auto mode can automatically force the unit into the Heat mode as needed When the UVC is in Auto mode it is normal for the UVC to idle in Heat mode when there is no need to switch to another mode The Heat mode super state consists of UVC states Heat 5 Low Limit E and Cant Heat B When the Heat mode super state becomes active the UVC automatically determines which of the Heat Mode states to make active based upon the transitions for each state Figure 11 Heat mode super state diagram Transition point UVC Mode Heat OR A UVC Mode Auto AND Space Warm UVC Mode Heat AND UVC Mode Auto v OR UVC Mode Auto AND Space Heat Mode mumu Warm AND Heat PI Sat Low Super State Heat Available Heat Available gt AND Low Limit Ina
60. oint A proportional band setting that is too small see Figure 21 causes control oscillations that go fully above and below the set point Figure 21 Proportional bands Too Small Too Large Actual Setpoint A proportional band setting that is too large see Figure 21 causes an offset between the actual measured oscillation center and the set point A small offset is not necessarily a problem since most systems have a small natural offset and the integral function automatically works to eliminate or reduce this effect 30 McQuay OM 751 Description of Operation In general it is best to start with a relatively large proportional band setting the factory default setting is best and adjust to smaller values If you want the system to respond strongly to small changes in the space adjust the proportional band to a higher setting If you want the system to react weakly to small changes in the space adjust the proportional band to a higher setting Integral Time The integral time or integral action causes the controlled output to change in proportion to time difference between the sensor value and set point The difference over time between the actual value and set point forms an area under the curve see Figure 22 The integral action works to reduce this area under the curve and to eliminate any natural system offset Figure 22 Integral time Area Under The Curve Too Small
61. onfigured to operate a Normally Open auxiliary heat device de energize when heat is required such as a wet heat valve actuator with a spring setup to open upon power failure However the Auxiliary Heat Configuration variable can be used to set the UVC to use a Normally Closed auxiliary heat device energize when heat is required such as electric heat Table 20 Auxiliary heat start stop calculation Start Stop Calculation Auxiliary heat Primary Heat PI Loop saturated high 100 for starts when more than two minutes AND EffectiveSpaceTemp lt EffectiveSetpoint AuxiliaryHeatStartDifferential Auxiliary heat EffectiveSpaceTemp 2 EffectiveSetpoint stops when AuxiliaryHeatStartDifferential AuxiliaryHeatStopDifferential McQuay OM 751 39 UVC Input and Output Table UVC Input and Output Table All UVC input and output connections and their corresponding unit ventilator usage are shown in the following table Table 21 Inputs and outputs software model 05 DX cooling only V0 Description BO 1 Inside Fan High BO 2 Inside Fan Medium BO 3 Electric Heat 1 BO 4 Electric Heat 2 BO 5 Electric Heat 3 BO 6 External Output Option 2 Fault Indication BO 7 BO 8 BO 9 Compressor BI 1 Condensate Overflow BI 2 BI 3 2 External Input Option 3 Ventilation Lockout default or Exhaust Interlock BI 5 External Input Option 2 Remote Shutdown BI 6
62. ovided to the unit OFF Mode State 9 Off mode is provided so that the UVC can be forced into a powered OFF condition OFF mode is a stop state for the unit ventilator it is not a power off state OFF mode consists of a single UVC state OFF 9 When OFF mode becomes active the UVC stops all normal heating cooling and ventilation OA damper is closed and fan operation ends The UVC continues to monitor space conditions indicate faults and provide network communications if connected to a network in the OFF mode while power is maintained to the unit While in OFF mode the UVC does not maintain DA temperatures If the space temperature drops below EHS while in the OFF mode the UVC is forced into the Emergency Heat mode see Emergency Heat Mode Super State on page 16 The space lighting output continues to operate based upon the current occupancy mode Note Special purpose unit modes such as Purge Pressurize and De pressurize can force the UVC to perform special functions during which the display appears to be in the OFF mode Figure 7 Off state diagram OFF UVC Mode OFF UVC Mode OFF Transition point 14 McQuay OM 751 Description of Operation Night Purge Mode State 8 Night Purge mode is provided as a means to more easily and quickly ventilate a space Night purge can be useful in helping to remove odor build up at the end of each day or after cleaning painting
63. ow the VCLL set point Compressor Operation The UVC is configured to operate the compressor as secondary mechanical cooling when the economizer is available When the economizer is not available and the compressor is available the UVC uses the compressor when cooling is required Compressor Envelope The compressor envelope protects the compressor from adverse operating conditions that can cause damage and or shortened compressor life by ending compressor operation if coil temperatures exceed the defined operating envelope For self contained units the UVC is configured to monitor both the inside air refrigerant and outside air refrigerant coil temperatures to prevent compressor operation under adverse conditions For split system units the UVC is configured at the factory to only monitor the inside air refrigerant coil as part of the compressor envelope function Figure 23 Compressor envelope in self contained units DX cooling 160 F 71 1 C Evaporator temperature indoor air coil HAHAHHA 28 F 2 2 C 120 F 48 9 C Condenser temperature outdoor air coil Hl Area for compressor operation envelope O Area where liquid slugging could occur O Area where starving could occur Compressor Cooling Lockout The UVC is configured to lockout compressor cooling when the OA temperature falls below the Compressor Cooling Lockout set point 63 5 F 17 5 C Below this point only
64. put you there is no change to the keypad display when you view space temperature Figure 3 Viewing indoor air temperature a gt 11 do Effective Enter Actual space Effective set point 5 sec temperature set point Changing Set Points The keypad display can be used to make a 5 F 3 C offset adjustment to the effective temperature set point See Figure 4 Also see Space Temperature Set Points on page 26 to learn more about temperature set points Figure 4 Adjusting the set point offset TO 0O gt 50 PG gt 1 gt B Effective Set point Enter Current set point offset offset Ny a i gt B gt B 50 gt 59 T N Adjusted Save Flash Effective offset change value set point Note The set point offset clears whenever UVC power is cycled When you change the set point offset after a power cycle or for the very first time this cleared value shows as the highest allowed value 5 F 3 C but is not an actual offset value When using the 3 F 1 7 C remote wall sensor any set point offset adjustment made at the keypad display causes the UVC to override and ignore the remote wall sensor set point adjustment knob To use the remote wall sensor set point adjustment knob after you changed the set point offset on the keypad display clear the keypad display set point offset by cycling UVC power When using the 55 F to 85 F remote wall sensor the UVC ignores any LUI
65. r Strategy 2 and uses the Temperature Comparison with Enthalpy Comparison Economizer function Note Temperature Comparison with Enthalpy Comparison requires both an optional OA humidity sensor and an optional IA humidity sensor Table 18 Economizer enable disable tests defined Economizer Tests enable disable tests Enable test Disable test A OA temp set point EffectiveOATemp lt EconOATempSetpt EconTempDiff EffectiveOATemp gt EconOATempSetpt B IA OA differential temp EffectiveOATemp lt EffectiveSpaceTemp 3 6 F EconTempDiff EffectiveOATemp gt EffectiveSpace Temp 3 6 F C OA enthalpy set point EifectiveQAEnthalpy EconOAEnthalpySetpi EffectiveOAEnthalpy gt EconOAEnthalpySetpt EconEnthalpyDiff IA OA differential EffectiveOAEnthalpy lt EffectiveSpaceEnthalpy z D enthalpy EconEnthalpyDiff EffectiveOAEnthalpy gt EffectiveSpaceEnthalpy Table 19 How economizer enable disable tests are selected EaopemIzss Space temp sensor OA temp sensor Shee Dara dts OA humidity sensor Economizer enable strategy sensor disable tests All Unreliable Don t care Don t care Don t care OA damper closed Don t care Unreliable Don t care Don t care OA damper closed Basic Reliable Reliable Don t care Unreliable TestB Reliable Reliable Don t care Reliable Test C f Test C and Either Expanded Reliable Reliable Don t care Reliable Tes
66. relay output provides one set of Normally Open dry contacts that can be used to signal the operation of the space lights When the UVC is in occupied standby or bypass occupancy modes the relay output signals the lights ON contacts closed When the UVC is in unoccupied occupancy mode the relay output signals the lights OFF contacts open External Binary Output 2 This output can only be used as a fault signal Fault Signal This relay output provides Normally Open Normally Closed and Common connections that can be used to signal a fault condition When a fault exists the UVC energizes this relay output When the fault or faults are cleared the UVC de energizes this relay output External Binary Output 3 This output can only be used to signal exhaust fan operation default or operate an auxiliary heat device 38 McQuay OM 751 Description of Operation Exhaust Fan ON OFF Signal This relay output provides one set of Normally Open dry contacts that can be used to signal the operation of an exhaust fan When the OA damper opens more than the Energize Exhaust Fan OA Damper set point then the relay output signals the exhaust fan ON contacts closed When the OA damper closes below this set point the relay output signals the exhaust fan OFF contacts open Auxiliary Heat Signal This relay output provides one set of Normally Open dry contacts that can be used to operate an auxiliary heat device The UVC by default is c
67. rge Air Temperature Discharge Air Position the Wet Heat Valve or y 9 Setpoint Output Temperature F amp BP Damper PI 5 CO optional Single Effective CO Setpoint Space CO5 Position the OA Damper PI 6 Law Limit Single Calculated Discharge Air Temperature Discharge Air Position the OA Damper Setpoint Temperature Figure 17 PI loop graphic for CO Effective COz set point Position the PI 5 p OA damper Space CO2 sensor Discharge Air Temperature Control The UVC uses two cascading PI loops to aid in providing very stable space temperature control The Space Temperature PI loop is used to calculate the Discharge Air Temperature Setpoint Output required to meet the Effective Temperature Setpoint Output A second PI loop Primary Cooling Secondary Cooling or Primary Heating is then activated to control the heating or cooling device required to achieve the calculated Discharge Air Temperature Setpoint Output Figure 18 Cascading PI loop graphic 1 primary heat Effective space Pet oo Discharge air temperature Space temperature temperature sensor Operate Auxiliary Heat set point sensor Figure 19 Cascading PI loop graphic 2 primary cool economizer Effective space om temperature Pl 1 DAT Setpt gt lt PI 2 Position the set point OA damper Space temperature Discharge air sensor temperature sensor McQuay OM 751 29
68. riority Table 11 Normal Energy hold off Energy hold off Off Off Energized Don t care Energy hold off Off Off Pressurize Don t care Don t care Don t care Off Pressurize De pressurize Don t care Don t care Don t care Off De pressurize Purge Don t care Don t care Don t care Off Purge Shutdown Don t care Don t care Don t care Off Off Network input Network output Normal indicates the UVC power up condition De energized indicates that the contacts connected to this binary input are open Energized indicates that the contacts connected to this binary input are closed AWN Table 11 Normal UVC mode priority Priority result Application override Unit mode pxemide Unit mode output 2 input input Heat Normal Auto Cool Emergency heat Heat Heat Normal Auto Cool Cool Night purge Night purge Off Off Emergency heat Emergency heat Fan only Fan only Heat Don t care Heat Cool Don t care Cool Night purge Don t care Night purge Off Don t care Off Emergency heat Don t care Emergency heat Fan only Don t care Fan only 1 Network input 2 Network output 3 Normal Auto is the normal UVC power up state McQuay OM 751 23 Description of Operation Occupancy Modes The UVC is provided with four occupancy modes Occupied Standby Unoccupied and Bypass The occupancy mode affects which heating and cooling temperature set points are use
69. s from the sensor Effect e CO Demand Controlled Ventilation function is disabled e Fault is indicated Change Filter Indication FF The Change Filter Indication fault occurs when the UVC calculates that the total fan run time has exceeded the allowed number of hours since the last filter change Effect e Fault is indicated EPROM Memory Indicator EE The EPROM Memory Indicator occurs when an unusual electrical event has scrambled the EPROM memory within the controller board In the event that this happens the controller board must be replaced Configuration Display The Configuration Display occurs when the display file cfg is incorrect or has not been downloaded with the appropriate file from service tools Troubleshooting Temperature Sensors The UVC is configured to use passive positive temperature coefficient PTC sensor whose resistance increases with increasing temperature The element has a reference resistance of 1035 ohms at 77 F 25 C Each element is calibrated according to the tables shown Use the following procedure to troubleshoot a suspect sensor 1 Disconnect both sensor leads from the UVC 2 Using some other calibrated temperature sensing device take a temperature reading at the sensor location 44 McQuay OM 751 Diagnostics and Service 3 Use the temperature reading from Step 2 to determine the expected sensor resistance from Table 23 4 Using a calibrated ohmmeter
70. s all normal heating and cooling While in Fan Only mode the UVC does not maintain DA temperatures If the space temperature drops below the EHS the UVC is forced into the Emergency Heat mode see Emergency Heat Mode Super State Figure 9 Fan only state diagram UVC Mode Fan Onl an Bae an On Ne N uve Mode N M Transition Fan Only A point McQuay OM 751 15 Description of Operation Emergency Heat Mode Super State The Emergency Heat mode is provided for situations where the UVC is in a mode that does not normally allow heating such as OFF Cool Night Purge or Fan Only If Emergency Heat mode is enabled the UVC can automatically force itself into the Emergency Heat mode from OFF Cool Night Purge Fan Only Purge Pressurize De pressurize and Shutdown Emergency Heat mode consists of UVC states Full Heat 7 and Cant Heat D Software model 05 does not have the primary or secondary heating devices The UVC uses auxiliary heat if field provided and field connected when emergency heat is required When the Emergency Heat mode becomes active the UVC automatically determines which state to make active Full Heat 7 or Cant Heat D based on the transitions for each of those states Figure 10 Emergency heat state diagram Emergency Heat Mode Super State Full Heat UVC Mode i A Emergency Hean Heat O RONEN ees ka UVC Mode Pba Transition Available Emergency Hea
71. s primary cooling economizer and secondary cooling mechanical DX as needed to maintain the effective cooling set point see Space Temperature Set Points on page 26 The keypad display or network connection can be used to force the unit into the Cool mode When the UVC is in Auto mode it is normal for the UVC to idle in Cool mode when there is no need to switch to another mode The Cool mode super state consists of the following UVC states Econ Mech 1 Mech 2 Econ 3 DA Heat 4 Low Limit F and Cant Cool C When the Cool mode super state becomes active the UVC will automatically determine which UVC state to make active based upon the transitions for each state If the space temperature drops below EHS and the Emergency Heat function is enabled the UVC will be forced into the Emergency Heat mode see Emergency Heat Mode Super State on page 16 18 McQuay OM 751 Description of Operation Figure 12 Cool mode super state diagram Transition D Point t UVCMode Cool AND UVCMode Auto OR UVCMode Auto AND Space Cold AND MechPI SatLow 3min AND EconPl SatLow UVCMode Cool UVCMode Auto AND Space Warm Na gt CoolMode SuperState Econ Available Econ MechCool Available Y 2 7 Paid ff MechCool Available lt Econ Available MechCool Available CantCool ZAVA EconTimer Expired N Econ Available 3 minutes AND X
72. set point offset adjustments Menu Reference The keypad display menu eases troubleshooting and simplifies UVC configuration The user can access the most common parameters and system status values without a PC or network interface The keypad display menu is accessed via an unmarked hidden key This hidden key is located approximately behind the letter h in the MicroTech II logo on the keypad display face The keypad display menu consists of two levels The first level is the keypad display Menu Item List containing alphanumeric characters representing each parameter The second level is where the parameter s value is viewed and adjusted if the parameter is adjustable After 15 seconds an inactivity timer automatically causes the display to back out of the menu levels returning to the effective set point display McQuay OM 751 Getting Started Figure 5 Changing a keypad display menu item Effective set point 10 gt gt A gt gt oc item to be changed First menu tem Use arrow keys to scroll and locate item Hidden key 10 sec g gt 20 gt AN gt 25 Current value New value Use arrow keys to adjust Select tem g gt 25 gt o gt 10 Effective set point Flash value Enter new value Table 7 Keypad display menu item list RO 05 Display Keypad menu ite
73. t B or Test A Reliable Reliable Reliable Reliable Test D and Test B Leading Edge Reliable Reliable Unreliable Reliable Test B atay Reliable Reliable Reliable Unreliable Test B Reliable Reliable Unreliable Unreliable Test B Note The hard wired sensor and the equivalent input must both be unreliable for the value to be considered unreliable McQuay OM 751 33 Description of Operation Networked Space Humidity Sensor Capability A networked space humidity sensor can be network interfaced with the Space Humidity Input variable When the Space Humidity Input variable is used valid value it automatically overrides the hard wired space humidity sensor if present Networked Outdoor Humidity Sensor Capability A networked outdoor humidity sensor can be network interfaced with the Outdoor Humidity Input variable When the Outdoor Humidity Input variable is used valid value it automatically overrides the hard wired outdoor humidity sensor if present CO Demand Controlled Ventilation optional Ventilation equipment typically uses fixed damper positions to determine the amount of OA for proper ventilation within the space Most commonly the fixed position of the OA damper is based on the maximum number of occupants the space is designed to accommodate However this fixed OA damper operation ignores the fact that most spaces during the day have varying occupancy levels and may only rarely reach maximum design o
74. t point Pi Cant Heat Full Heat State State 7 The Full Heat 7 state is the normal state that the UVC goes into when Emergency Heat mode is active It is activated when the space temperature is lower than the EHS When Emergency Heat mode becomes active the UVC goes into 100 heating until the space temperature raises to the EHS plus a fixed differential 5 4 F 3 C In the Emergency Heat mode the space fan is set to high speed and the OA damper operates normally If the UVC automatically forces itself into the Emergency Heat mode from another mode e g Cool Fan Only etc then the UVC returns to the appropriate unit mode once the space temperature rises to the EHS plus a fixed differential 5 4 F 3 C The UVC monitors the DAT to ensure it does not exceed DAHL If the DAT does exceed DAHL then heating is set to 0 for a minimum of 2 minutes fixed and until the DAT drops 36 F 20 C fixed differential below DAHL Cant Heat State State D The Cant Heat D state is a non normal state that the UVC can go into when Emergency Heat mode is active An IAT or DAT sensor fault during Emergency Heat mode causes the UVC to make this state active When the Cant Heat state becomes active the space fan remains at high speed as set during the Full Heat state The UVC will remain in the Cant Heat state until heat becomes available 16 McQuay OM 751 Description of Operation Auto Mode Aut
75. the optional remote wall mounted sensor with 3 F adjustment If you have the optional remote wall mounted sensor with 3 F adjustment and an occupant uses the keypad to make Set Point Offset adjustments this overrides any 3 F adjustment on the optional remote wall mounted sensor since the keypad display has higher priority If you find that changes to the 3 F adjustment on the remote wall mounted sensor have no effect it is likely that an occupant used the keypad display to make a Set Point Offset change Cycle unit power to clear this situation and restore the ability to change the Set Point Offset from the 3 F adjustment on the remote wall mounted sensor Remote Wall Mounted Sensor with 55 F to 85 F Adjustment optional When the optional remote wall mounted sensor with 55 F to 85 F adjustment dial is used the UVC will effectively write the value of the set point dial to the Space Temp Set Point Input variable Note If a network connection is using the Space Temp Set Point Input variable do not use the optional remote wall mounted sensor with 55 F to 85 F adjustment If it is intended that the LUI will be used by room occupants to adjust the Setpoint Offset then you must not use the optional remote wall mounted sensor with 55 F to 85 F adjustment When using the optional remote wall mounted sensor with 55 F to 85 F adjustment the UVC will ignore any Setpoint Offset changes made at the LUI Effective Set
76. to clear this variable and return the UVC to normal operation Lo Occupied Coolingset OCS Adjust occupied cooling set point RW x AT LO point J P 9 967 ale 23 C LS a Cooling Set SCS Adjust standby cooling set point RW x Kaka cu oo Hoping 2H UCS Adjust unoccupied cooling set point RW x eed Ho e Heating Set OHS Adjust occupied heating set point RW x a re H5 ng y Heating Set SHS Adjust standby heating set point RW x o Hu ae Heating Set UHS Adjust unoccupied heating set point RW x aes r5 Wall Sensor Type Set wall sensor type 0 3F 1 55 F to 85 F RW x 0 al eats Ou oo OADP Display OA damper position RO x OAD Min Position High Adjust OA damper minimum position with IAF at high speed This variable is 7 oc Speed Set point OAD factory set to 5 open when the unit is ordered with optional CO DCV RWO X ae OAD Min Position Med Adjust OA damper minimum position with IAF at medium speed This variable is ni Speed Set point OADM not used when the optional CO DCV is enabled Only OADH is active as the OA RW x 25 damper minimum regardless of fan speed OAD Min Position Low Adjust OA damper minimum position with IAF at low speed This variable is not oH Speed Set point OADL used when the optional CO DCV is enabled Only OADH is active as the OA RW x 30 damper minimum regardless of fan speed 10 McQuay OM 751 Getting Started
77. types displayed over Metasys N2 and BACnet MS TP networks using RW x F Temperature Units x bears the appropriate optional communications modules 1 RW read and write capable RO read only 2 If a menu value is greater than 2 digits higher than 99 then rr will be displayed on the keypad display McQuay OM 751 11 Description of Operation Description of Operation State Programming The MicroTech II UVC takes advantage of state machine programming to define and control unit ventilator operation State defines specific states or modes of operation for each process within the unit ventilator e g heating cooling etc and contain the specific logic for each state This eliminates some of the most common problems associated with control sequences such as the possibility of simultaneous heating and cooling rapid cycling etc State machine programming and the unique nature of state diagrams can be easily used to describe operation It can simplify sequence verification during unit commissioning as well as simplify troubleshooting With the unique combination of state machine programming and the keypad display s ability to allow a technician to easily determine the active UVC state troubleshooting the UVC can be very simple The state diagrams presented in the following sections consist of several elements including super states states conditional jumps also called transitions and transition points Super
78. ual unit alarm or fault condition but only a condition used for the purpose of transition arguments Low Limit State State E The Low Limit state is a non normal state the UVC can go into while Heat mode is active when the unit reaches 100 heating and still cannot meet the current DATS see Discharge Air Temperature Control on page 29 required to maintain the effective heating set point see Space Temperature Set Points on page 26 This is likely to occur only if the OA temperature is very cold the OA damper minimum position is set too high the unit ventilator is oversized for the application or if the electric heating has failed or is set incorrectly When the Low Limit state becomes active the Low Limit PI loop can override the OA damper position see Outdoor Air Damper Operation on page 32 and adjust the OA damper toward closed as necessary to maintain the current DATS see Discharge Air Temperature Control on page 29 Cant Heat State State B The Cant Heat state is a non normal state the UVC can go to when Heat mode is active An IAT or DAT sensor fault during the Heat mode causes the UVC to make this state active When the Cant Heat state becomes active no heating or ventilation takes place The OA damper goes to the minimum position unless it is forced closed by other functions such as freezestat T6 or morning warm up Cool Mode Super State When in Cool mode the UVC use
79. upied heating and cooling set points the OAD operates normally and by default the IAF remains on Additional Occupancy Features Networked Occupancy Sensor Capability A networked occupancy sensor can be interfaced with the Occupancy Sensor Input variable to select occupancy modes When the Occupancy Sensor Input variable is used it automatically overrides any hard wired unoccupied binary input signal Unit Mounted Time Clock An optional unit mounted factory installed electronic 24 hour 7 day time clock can be provided on stand alone unit ventilator configurations It is factory wired to the UVC unoccupied binary input and can be set to automatically place the unit into occupied and unoccupied modes based upon its user configured schedule Unit Mounted Tenant Override Switch A tenant override switch is factory installed in all floor mounted units and is located near the LUI on the unit This switch provides a momentary contact closure that can be used by room occupants to temporarily force the UVC into the bypass occupancy mode from unoccupied mode Note The Occupancy Override Input can override the tenant override feature For example if the network uses the Occupancy Override Input to force the unit into unoccupied mode then the unit mounted tenant override switch does not operate as expected Therefore McQuay strongly recommends using the Occupancy Sensor Input to control occupancy modes over a network and only using the Occupancy
80. work both affect the Set Point Offset Input variable Keep in mind that changes to this variable are last one wins Networked Set Point Shift Capability The Set Point Shift Input variable is used to shift the effective heat cool set points It typically is bound to a networked supervisory controller or system that provides functions such as outdoor air temperature compensation All occupied standby and unoccupied set points are shifted upward or downward by the corresponding value of the Set Point Shift Input variable Note The Set Point Shift Input capability is not available through the BACne interface Networked Space Temperature Sensor Capability A networked space temperature sensor can be interfaced with the Space Temp Input variable When the Space Temp Input variable is used valid value it automatically overrides the hard wired space temperature sensor 26 McQuay OM 751 Description of Operation Remote Wall Mounted Sensor with 3 F Adjustment optional When the optional remote wall mounted sensor with 3 F adjustment dial is used the UVC effectively writes the value of the set point adjustment dial to the Set Point Offset Input variable Note If a network connection is used to adjust the Set Point Offset Input variable you must not use the optional remote wall mounted sensor with 3 F adjustment If the keypad display is used by room occupants to adjust the Set Point Offset do not use
81. ycling Set space fan cycles switches off during occupied bypass and standby mode 2 L h A _ RW x 2 Configuration continuous 3 cycling LE Filter Alarm Enable Set filter alarm status 0 disable 1 enable RW x 0 Cr Reset Filter Alarm Input Enter 1 to clear filter alarm RW x Pr C l Compressor Enable Set compressor status 0 disable 1 enable RW x 1 Adjust compressor cooling lockout set point When the OA temperature falls below re Compressor Cooling CCLO this set point compressor cooling is not allowed DO NOT make this setting lower RW x 63 5 F L Lockout Set point than the factory default There is a fixed 3 6 F 2 C differential associated with 17 5 C this set point rJ Compressor Heating CHLO Adjust compressor heating lockout set point When the OA temperature falls below RW x 25 F 5 Lockout Set point this set point compressor heating is not allowed and only electric heat will be used 4 C Adjust compressor start delay Where several units inductive loads are CE Compressor Start Delay connected to the same electrical supply make this set point unique for every UVC RW x 0 sec to prevent multiple compressors from energizing at the same time after a power failure or occupancy change oP Space Temp Sensor Adjust this setting to bias the UVC measured space temperature RW x 0 Offset fi Keypad displa Set keypad display temperature units in English or SI This set point also effects Luin YP pay which unit

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