Home

Mini-MOD and Mini-Extension Installation Manual

1. LAARS Sequencing Controls S8 amp S8EXT WIRING WIRING THE POWER TERMINALS 1 2 Bring the 120VAC 60Hz power wires through the bottom Knockout of the enclosure Class 1 voltages must enter the enclosure through a different opening from any Class 2 voltage wiring Connect the hot line to terminal marked L Connect the neutral line to the terminal marked N WARNING Class 1 voltages must enter the enclosure through a different opening from any Class 2 voltage wiring Laars recommends installing a surge suppressor on the power source to the S8 WARNING Connect the shield at the control terminal end and cut the shield wire at the sensor end WIRING THE SENSORS SYSTEM TEMPERATURE SENSOR WIRING TERMINALS 27 28 A S8 must be connected to a temperature sensor located in the common header e S8 is designed to be connected to a temperature sensor CA002400 or equivalent for immersion in a 3 8ID well CA002500 or equivalent Contact the factory for additional temperature sensor options Temperature sensor wires can be extended up to 500 by splicing shielded 2 conductor cable Belden 8760 or equivalent e Temperature sensors have no polarity Connect the two wires from the sensor to the S8 terminals marked SYSTEM TEMP 27 28 e Connect the sensor shield to the circled terminal 28 with one of the sensor wires OUTDOOR SENSOR WIRING TERMINALS 29 30 When Outdoor Reset is selected the S8 w
2. 6 Minimum Return lll less 22 INITIAL SETUP o lene 6 gystemSetngs 1023 IU AOS AA lie Program Change Settings 23 INSTALLATION 7 Stage Settings 23 Mounting the Enclosure 7 Reaction Time 0 0 23 Install the Sensors 8 Purge Delay da 23 System Sensor Installation 8 Minimum 23 Outdoor Sensor Installation 8 Standby Delay 23 a RG ae Re 9 Last Stage Hold 24 Wiring the Power Terminals 1 2 9 ThrotleRange 24 Wiring the 9 Lead Settings 24 Wiring the Domestic Hot Water DHW Sensor Lead Boiler i cios oos geben 25 Terminals 33 34 10 Rotate Mode lt lt lt 25 Wiring the Shutdown Terminals 35 36 10 Setback Schedule 25 Wiring the Setback Terminals 35 36 10 Setback a 25 Wiring the Prove Terminals 37 38 10 BOOSts amp 220 spo eh bh bd Rosse NU EUR 25 Wiring the System Output Terminals 19 20 10 BoostPeriod ra ni kdai 26 Wiring the DHW Pump Terminals 21 22 11 Day Night Schedules 26 Wiring the Comb Air Damper Terminals 23 24 11
3. n Winter if the DHW Priority Timer was set to a value other than NO a DHW call will de energize the System relay and energize the DHW Pump relay This will remain for the period of the DHW Priority Timer setting or until the DHW call terminates whichever is sooner If the DHW call was still active after the DHW Priority Timer elapses the System relay will energize for the remaining of the DHW call period DHW PRIORITY TIMER AVAILABLE WITH PARALLEL DHW PIPING Adjustable NO 1 to 120 minutes Default NO Button MENU System Settings DHW Settings DHW Prior Timer in Parallel e The DHW Priority Timer provides the user with the capability of selecting the DHW Priority period If NO was selected both DHW Pump and System relay will be energized on a DHW call whenever the control is set to Winter and the Outdoor temperature is below or at the Outdoor Cutoff In Summer a DHW call will energize only the DHW Pump relay leaving the System relay de energized Ifthe DHW Priority Timer was set to a value other than NO a DHW call in the Winter when the Outdoor temperature is below the Outdoor Cutoff will cause the System relay to de energize and the DHW Pump relay to energize for the period of the DHW Priority Timer or until the DHW call expertise whichever happens sooner If the DHW call did not expire within the Priority period then the System relay will energize was a DHW call during Summer or when the Outdoor temperatu
4. Heating Systems 9 Q Stage A o Stage E Q Stage B Q Stage F Qo Stage Q Stage G Q Stage D Q Stage H INPUT RATINGS 115VAC 60Hz 12VA MAX Use Copper Conductors Only CAUTION Risk of Electric Shock Uniti Unit2 Unit3 Pump Pump Pump Unit4 Pump 58 system ouweruve O ee T MAN NT EQUIPMENT C LISTED 99 PROGRAM po RUN SEQUENCING CONTROL DO NOT APPLY ANY VOLTAGE TO INPUT TERMINALS SENSORS MUST BE GOLD SERIES 1018 Lo TE to Ke Sensor Shiled Sensor Shiled Prove Dry Contact Shutdown Dry Contact Page 33 Page 34 LAARS Heating Systems SPECIFICATIONS Voltage Input 0 120 VAC 60 Hz Power Consumption O 12 VA Max Operating Temperature 20 F 7 C to 120 F 49 C Operating Humidity 0 20 to 80 Dimensions 0 11 Wx9 Hx 3 Weight O 2 5 pounds S8 Specifications Lead Stage Rotation Time 1 to 999 Hours 41 days Manual First On First Off S8 Outputs and LEDs 11 N O S P S T 8 Stages 1 System 1 DHW Pump 1 Combustion Air S8 Inputs 1 Sys Temp 1 Outdoor Return Temp DHW Temp Ext Setback Shutdown Prove Stage Modes 0 Auto Standby Off On Standby Time PID only 1 to 60 minutes Output Relay Ratin
5. Setback Boost e This features allows a building to either warm up or cool down quickly after a Setback period to bring the building to the desired temperature faster The Boost temperature will be the number of degrees to be added in Heating or subtracted in Cooling from the Calculated Target Temperature e Using the previous example if the Target was 180 F and the Setback was 20 F and the Boost was 10 F for 30 minutes after the setback period the Boost will change the des to 190 F d a period of 30 minutes The new Set Point will appear on the main display indicating this condition Page 26 LAARS Heating Systems BOOST PERIOD Adjustable 0 to 120 minutes Default 30 minutes Button MENU System Settings Setback Boost Boost Period e This will determine the amount of Boost the system will receive e If External Signal was selected as the Setback Mode the Boost will start when the switch from Setback to normal operation takes place and will continue for the full Boost Period An example would be if the Boost Period was set to 30 minutes and the shorting of the Setback terminals has ended at 7 00Am the Boost will start at 7 00Am and will terminate at 7 30Am where the control will resume normal operation If Day Night Schedule was seleceted as the Setback Mode the Boost will start a full Boost Period prior to the switch from Night Setback to Day normal operation If the Day was set to start at 7 00Am the Boost Period was
6. 42683 31215 23089 19939 17264 14985 13040 11374 e Reaction Time and Minimum Runtime If the system is overshooting or undershooting adjust Minimum Runtime or the Reaction Time That depends on if the stages are brought on fast and were not allowed to turn off until the Minimum Runtime elapsed Or the stages were brought on slowly however were allowed to turn off quickly e PID vs OSS If the application the system is used on requires fast response that the normal PID mode cannot provide try using the OSS mode and adjust its parameters according to the system requirements Page 32 LAARS Heating Systems MULTIPLE BOILERS WITH PUMPS PIPING DIAGRAM Outdoor Sensor 120VAC System Sensor o gcn olg ANM E ME RR Building Heating Loop System The S8 sequencing 4 single stage boilers and their boiler pumps The boilers are piped in Reverse Return on the primary loop The System output is controlling the System Pump Laars Heating Systems is aware that each installation is unique Thus Laars Heating Systems is not responsible for any installation related to any electrical or plumbing diagram generated by Laars Heating Systems The provided illustrations are to demonstrate Laars Heating Systems s control operating concept only LAARS Sequencing Controls S8 amp S8EXT MULTIPLE BOILERS WIRING DIAGRAM
7. Button MENU System Settings gt lt Stage Settings gt Reaction Time in PID Logic only 1015 the amount of time it takes a single stage to affect the system e After the S8 turns on a stage trying to meet a set point it will not turn on another stage until the reaction time has elapsed Then it will recalculate if a stage is need e determine the optimum time in a heating system start with a hot system However in a cooling system start with a cool system Then turn on a single stage and calculate how long it takes until the system begins to respond to that stage That period should be set as the Reaction Time PURGE DELAY Adjustable 0 0 10 0 minutes Default 0 0 minutes Button MENU System Settings gt lt Stage Settings gt Purge Delay in PID Logic only e Most large units must go through a purge cycle before they are brought on line When the 58 activates a unit the lowest stage on a unit it does not start to calculate its output until the Purge Delay is over This allows the unit to fully come on line and to begin producing output e The Purge Delay helps to prevent short cycling of a newly activated units Once the lowest unit stage is activated it MUST run through the entire Purge Delay period The minimum Purge Delay setting MUST be set to the time required by the units manufacturer specification MINIMUM RUNTIME Adjustable 1 60 minutes Default 2 minutes Button MENU System Settings gt lt S
8. supplied with the control and achieves better fuel savings in addition to better comfort Using an optional X SIG Interface CA004200 the S8 can receive an external 4 20mA Set Point through EMS system PID OR OSS CONTROL LOGIC The S8 PID can be used for applications where system reaction will require a long period to achieve or measure the results However OSS can be used for applications where the load changes frequently and the sequencing must match the load and its immediate change NUMBER OF STAGES S8 can be configured to control up to eight stages It can control up to 24 stages using a maximum of two S8 Extension Panels each with eight stages STAGE PUMPS OR VALVES e S8 can control muliple stages in addition to unit pumps valves CONTROL DHW PUMP AND COMBUSTION AIR DAMPER e The control of DHW is based on either a temperature sensor can be purchased separately on the DHW source or using a dry contact from an aquastat The S8 provides multiple DHW Priority options to choose from based on the DHW piping The Combustion Air Damper output can control the equipment while utilizing the Prove input to check the status on the Combustion Air Damper End Switch System Pump Flow switch or any other checking devices before any stage is energized MONITOR BOILER RETURN optional return line sensor can be purchased separately can be connected in heating applications to monitor and help protect the boile
9. COMBUSTION AIR DAMPER OPERATION e The S8 controls multiple relays each controlling different types of equipment In addition to the control of the boilers or cooling units it can control the primary system pump unit pumps or valves a DHW pump and a combustion air damper The operation of those relays depends on the Startup and System Settings RUN ON Adjustable 0 to 60 minutes Default 2 minutes Button MENU System Settings Run On Run On applies to all pumps valves and dampers It is the additional time a pump valve or a combustion air damper will run after the output unit relays has de energized For pumps and valves it is used to dissipate the excess energy from the heating or cooling system into the building For a combustion air damper it brings in enough fresh air for the next boiler fire up The Run On time should be set based on the size and type of the equipment A boiler with low water content and high horsepower will need a longer Run On than a boiler with the same horsepower but has more water content PUMP EXERCISE Adjustable Off On Default Off Button MENU System Settings Pump Exercise The S8 provides an option to exercise pumps for 10 seconds when not used for seven days This option reduces pumps impellers locking during the off season period MAINTENANCE Button MENU lt Maintenance gt The Maintenance menu gives access to sensor and outputs trimming In addition you ll have access to
10. Program Change Settings 20 SEASON kee bn oa Ee RE QU dex dou 20 ResetRatio c n 20 Customized Reset Ratio 20 LAARS Sequencing Controls S8 amp S8EXT S8 LAYOUT Program Switch to restrict access to function changes This Switch is covered with Enclosure Wiring Cover LEDs indicate associated relay s status Button function is presented on bottom row of the display geA g R B g age g ge D g D kl PUT RA 60 D O R O O ejeje d PWR E L N CE R e O PROGRA OUTPUT RATING 6 AMP R AMP PILOT DUTY PER OUTPUT AT 120VA DHW COMB B Sa 4 6 8 9 10 4 6 8 19 20 4 EEG INNEN RS485 pus Per RETURN EJ E SIsisisisisisisisisisilsbs isisisisisis sis co SESSSESESSSSSSS H De f SN UN m Y Y H H H H HH HH Output Relays to manage the stages When connecting Temperature Sensors no System Output controls pumps valves or other system components DHW Pump and Comb Air relays are controlled when configured Polarity is observed Prove terminals must be connected for S8 to operate stages Connect to Extension panels to add additional stages or connect to X SIG Interface for external 4 20mA
11. Set Present Time 26 Wiring the Stage Terminals 3 17 11 DHW Settings o 27 DHW Priority Timer Available with Parallel DHW MENU SEQUENCE 12 Piping o oo a a a 27 DHW Set Point Requires an Optional DHW oo EET Paneis and A i Temperature Sensor 27 DHW Differential 27 A E Ae o a ME M b Pump Valve and Combustion Air Damper Operation28 Run On 26 Control Mode D A M CC E MM EE 16 Pump Exercises 24 24 4644 8448 6408 44 28 Display UI has MODERN 18 Maintenance lees 28 a AUMIA set Tone AVAlaAbIE ip e System amp Outdoor SensorTrim 28 Application sis essi T oniguaion DHW Piping Available with Heating Only 17 Di ISDIay oom X Rum aod 29 DHW Pump Output 17 Stage Settings 30 Combustion Air Damper Output 17 Mode L 30 Setback 17 18 RunTlme s 44 6 4 4 6 deem a a RS 30 18 TROUBLESHOOTING 31 Sane ei dd 18 32 Sequence AUD dos 18 WIRING DIAGRAM 33 ControlLogic lens 18 Sensor Fault 194 Sree ome air os Operating 5 20
12. needed it will fire the lower stage of the lag unit followed by the higher stage of the lag unit CONTROL LOGIC PID OSS Over Sized System Default PID Button MENU System Startup gt Sequencing The PID option allows the S8 to sequence stages based on Reaction Time and Boiler Min Run Time The PID relies on the rate of change in the System Temperature The PID logarithmic calculations foresee changes and sequence stages based on those changes It is the most efficient operation for most heating and cooling applications LAARS Sequencing Controls S8 amp S8EXT Page 19 e The Oversize option sequence stages based on how many Throttling ranges differentials is the system temperature away from the Target Temperature In Heating and at one Throttling range below the Set Point only one stage will be on For each additional Throttling range below the Set Point an additional stage will be activated The last stage on will be allowed to exceed the Set Point by one Throttling range before turning off that stage This helps to prevent the last stage from short cycling When PID is Selected the following are the settings that directly affects this modes operation e Reaction Time SELECT Settings System Settings Stage Settings Reaction Time e Purge Delay SELECT Settings System Settings Stage Settings Purge Delay e Minimum Run Time SELECT Settings System Settings Stage Settings Min Runtime e Standby Delay SELECT Settings System Setti
13. set point Page 3 Page 4 LAARS Heating Systems S8 OVERVIEW SEQUENCES UP TO 8 STAGES WITH PUMPS OR VALVES The S8 is the perfect control whenever multiple boiler or chiller stages are required for hydronic heating or cooling applications The S8 controls the stages and their pumps or valves to maintain a precise system set point PID OR OVER SIZED SYSTEM OSS LOGIC The S8 s control algorithm allows it to look at the rate of change in the system If the load is changing quickly the S8 can be set to OSS sequencing where it will react based on load changes If the system fluctuations are minimal as in heating applications the S8 will make slow and gradual output adjustments Therefore the S8 adapts to specific system requirements and minimizes fluctuations around the set point DIGITAL DISPLAY OF ALL SYSTEM SETTINGS The S8 s alphanumeric digital display names each system parameter in simple English and shows its precise value The easy to follow menu system allows users to quickly make changes to any system setting without having to learn any specialized codes or keyboard commands AUTOMATIC ROTATION AMONG STAGES Rotating the first stage to be activated on a call for output promotes even wear on each unit The S8 has three modes of rotation Manual FOFO or Time The Time rotates the lead stage every selected time period from every hour to every 41 days OUTDOOR RESET WITH CUSTOMIZABLE CURVE The S8 has a hydronic outdoor temperatur
14. set to Program The switch is located under the Enclosure Wiring Cover for security The Enclosure Wiring Cover can be securely closed using a padlock procRAM RUN STARTUP SEQUENCE Button MENU System Startup When powered the S8 performs a self test on its components After the self test diagnostics have been successfully completed the S8 will initialize the panel On the first power up the System Startup screen will appear after the initialization 1s complete If it doesn t the S8 has already been configured The System Startup menu sets the main parameters like the type of sensor the type of output whether heating or cooling the sequencing mode and many other parameters described in this section e Before entering the Startup menu several warnings will alert you about the consequences of making Startup changes CONTROL MODE Outdoor Reset Set Point EMS 4 20mA Default Set Point Button MENU System Startup gt Control Mode e Outdoor Reset provides a variable set point based on outdoor temperature Available for Heating applications only Outdoor Reset mode requires the use of an outdoor sensor DO NOT select Reset without an outdoor sensor Set Point mode does not require an outdoor sensor If an outdoor sensor is connected in Set Point mode it will be used only as an outdoor cutoff point That is to turn the stages system and Comb Air relays off EMS 4 20mA allows the 58 to receiv
15. view the Startup configuration settings as well as sensor histories CAUTION To be able to change the S8 settings the Program Run Switch must be set to Program The switch is located under the Enclosure Wiring Cover for security The Enclosure Wiring Cover can be securely closed using a padlock SYSTEM amp OUTDOOR SENSOR TRIM Adjustable 20 F 11 C to 20 F 11 C Default 0 F Button MENU lt Maintenance gt System Trim Button MENU lt Maintenance gt Outdoor Trim Button MENU lt Maintenance gt Return Trim Button MENU lt Maintenance gt DHW Trim e The Laars thermistor type sensors are very accurate and normally require no calibration However sometimes it may be desirable to make small adjustments to the displayed value Do not use the Trim setting to make the Outdoor temperature sensor match the reported on the radio or TV Outdoor temperature can vary widely over a broadcast range HISTORY Button MENU lt Histories gt The S8 provides users with a graphical history of the System Outdoor DHW and Return temperatures for the previous 24 hours The temperatures are sampled every 12 minutes That is readings of temperatures are recorded and stored every 12 minutes for the last 24 hours LAARS Sequencing Controls S8 amp S8EXT Page 29 e To view the values of specific time period use the two middle buttons to scroll to that time and read the upper left temperature The first screen will be the
16. A at each end of 4 20mA range LAARS Sequencing Controls S8 amp S8EXT Page 17 APPLICATION Heating BreakOnRise Cooling MakeOnRise Default Heating BreakOnRise Button MENU System Startup gt Application e The 58 offers two application modes Heating and Cooling In Heating the S8 will sequence stages and when the system temperature is below the set point In addition the system relay will energize when the outdoor temperature 15 at or below the Outdoor Cutoff setting In Cooling the S8 will sequence stages and when the system temperature is above the set point In addition the system relay will energize when the outdoor temperature is at or above the Outdoor Cutoff setting Return Temperature monitoring or DHW options will be available in cooling applications DHW PIPING AVAILABLE WITH HEATING ONLY Parallel Primary Secondary Default Parallel Button MENU System Startup gt DHW Piping When Parallel is selected the S8 will offer a DHW Priority Timer The DHW Priority will only take place during heating periods The Parallel option will allow the DHW Pump relay to energize while de energizing the System relay when there is a DHW call during heating However during Summer only the DHW Pump relay will energize on a DHW call e Selecting the Primary Secondary option will energize the System relay with the DHW Pump relay whenever there is a call for DHW even during the Summer or when outdoor temp
17. Document 4213 Laars Sequencing Controls Sequencing Model S8 and S8Ext Output panel to Sequence up to 24 individual stages with lead lag and manual override capabilities 26 E ISISISIS IS SISISISISISISIS SIS FOR YOUR SAFETY This product must be installed and serviced by a professional service technician qualified in hot water heater boiler controls installation and maintenance This manual is intended for anyone who will install operate or maintain the control system Before you begin installation and operation of this control it is important that you thoroughly review this manual Improper installation and operation could result in damage to equipment and possibly even personal injury Laars Sequencing Controls are not intended for use as operation safety limit controls Another control that is intended and certified as a high limit control must be in the water heater boiler control circuit Heating Systems Company A subsidiary of BRADFORD WHITE Corporation Page 2 LAARS Heating Systems S8 LAYOUT orm Rs 3 Outdoor Cutoff Temperature 21 58 4 ae UNDERSTANDING OPERATION CONCEPT 5 Maximum Target 2 22 Reset Ratio Outdoor Reset 5 Boiler Minimum 22 Make Sure You Have the Right Control
18. E SYSTEM SENSOR e Put the System sensor approximately 10 feet past the last heating cooling unit on the common supply header but before any major takeoffs e The sensor must be located where it sees the output of all the stages If a unit Is piped so that the sensor does not see its output the S8 will not sequence the units correctly e Only use a Standard Brass Tube sensor CA002400 or equivalent The sensor wires be extended up to 500 using a shielded 2 conductor cable Belden 8760 or equivalent Do not ground the shield at the sensor but at the panel using one of the terminals marked with an Do not sensor wires in conduit with line voltage wiring Sensor Probe Heating System Sensor Strap On Heating System Sensor Common Supply Pipe Pipe Insulation IMMERSION HEATING SYSTEM SENSOR HSS INSTALLATION e Install a 3 8 ID immersion well CA002500 or equivalent e Insert the sensor probe of the supplied sensor into the well Sensor Probe A CAUTION STRAP ON HEATING SYSTEM SENSOR HSS INSTALLATION If the System Sensor can not sense the Strap the sensor to the pipe using metal clamps Do not over tighten the correct system water temperature being clamp supplied to the building the S8 will not Strap pipe insulation around the sensor and pipe provide comfortable heat cool levels Be sure that it is located on a main supply pipe whic
19. F Custom Reset Ratio SET POINT NOT ADJUSTABLE IN EMS MODE Adjustable 10 F 23 C 230 F 110 C Default 140 F 60 C Button MENU Set Point In Set Point or EMS 4 20mA e The Set point is the temperature value the S8 will use to control the system The S8 will add subtract or hold the stages of the heating or cooling units to maintain the system temperature around the Set point e system can be expected to fluctuate around the set point The amount of fluctuation depends on the System Settings and Stage Settings fan Outdoor Sensor was connected pressing the SAVE button will switch to the Outdoor Cutoff setting option e Ifthe EMS Mode was Enabled the Set Point will be set by the EMS BMS system and will be available to be only read e The range of Set Point in the EMS is set in the Startup menu at 4mA and 20mA Any reading below the 2mA or above 22mA will indicate a uo E message on the Message Line OUTDOOR CUTOFF TEMPERATURE Adjustable Off 20 F 7 C 100 F 38 C On Default 70 F 21 C Button MENU Set Point Outdoor Cutoff in Set Point Button MENU Outdoor Reset gt Outdoor Cutoff in Reset e n Outdoor Reset mode Outdoor Cutoff will always exist However in Set Point mode if the outdoor sensor is installed the Outdoor Cutoff screen will automatically appear after the temperature Set Point has been selected n Heating applications when the outdoor temperature falls to t
20. LVE OUTPUTS Each Stage output A through H has one Normally Open N O relay contact When wiring several multi stage units start with the lower stage of the first unit and wire it to Output A followed by the higher stage of the same unit and wire it to Stage B If the S8 is configured to operate Stage Pumps or Valves then wire them using the stage after the highest stage for that unit That is the low stage for the first unit must be connected to A and the higher stage of the same unit must be connected to Stage B The Valve or Pump for the same unit must be connected to Stage C Page 12 LAARS Heating Systems MENU SEQUENCE STARTUP CAUTION To be able to change the S8 settings the Program Run Switch must be set to Program The switch is located under the Enclosure Wiring Cover for security The Enclosure Wiring Cover can be securely closed using a padlock EMS SET POINT Y MAINTENANCE LAARS Sequencing Controls S8 amp S8EXT Page 13 SET POINT RESET RATIO DHW SETTINGS Page 14 LAARS Heating Systems STAGE SETTINGS SCHEDULES STAGE MENU LAARS Sequencing Controls S8 amp S8EXT CONNECTING TO THE S8EXT PANELS AND XSIG INTERFACE The S8 is equipped with a 6 pin phone socket to connect to SSEXT panels or XSIG Interface Only 6 wire phone cable provided must be used for proper operation Page 15 Each S8 Extension has two RS485 communication ports Use one to conn
21. SYS was initially selected change the selection to 1 25 OD 1 00 SYS 110 Water Temperature e e 70 60 50 40 Outdoor Temperature CUSTOMIZED RESET RATIO Button MENU Outdoor Reset gt Reset Ratio Custom FO can be used The Custom Reset Ratio is only available when is selected from the Reset Ratio menu option It provides the user with the capability of assigning two points on reset ratio diagram use the line that connects those two points as the customized reset ratio curve Each of the two points will need a specific System and Outdoor Temperature to identify it on the diagram LAARS Sequencing Controls S8 amp S8EXT Page 21 Set the first point specify Sys Temp 1 and OD Temp 1 Then specify Sys Temp 2 and OD Temp 2 to set the second point on the curve The two points can be anywhere on the line not necessarily at the ends e The chart shows an example of a customized curve 6 OD 5 SY S that does not exist in the standard curve options If the outdoor temperature reaches 30 F the system target will be 145 F e Remember that the Min Target and Max Target apply to all reset ratios including the customized reset ratio ones Point1 System 120 F Point2 System 170 F F Oudoor Oudoor 0 F 180 Max Target TO p a Water Temperature in Bus N e e 100 Li i HM 70 60 50 40 30 20 10 0 10 20 Outdoor Temperature in
22. System Temperature History By clicking on the Next button you ll be able to view the Outdoor Temperature History then the Return History followed by the DHW History CONFIGURATION Button lt gt lt Configuration This menu option provides a consolidated view of the Startup settings e Additional settings will be available by selecting the NEXT option DISPLAY The 58 display layout provides a variety of information that gives an immediate picture of the operation status The display shows four heating or cooling units at a time The two middle buttons scrolls the screen to view additional boilers Moreover all the information is brightly displayed It can be viewed in brightly or dimly lit rooms e The buttons functionality changes based on the screen and menu level The buttons functionality is displayed on a dark background on the screen bottom line Horizontal arrows are to scroll through the available stages Vertical arrows are to scroll through the menu functions System Temp Outdoor Temp when in menus or to change values of settings when in its Y specific screen Message Display Line Units and their Status DISPLAY OUTPUT STATUS The S8 unit sequencing status gives immediate access to each unit status The following list show all possible boiler status e AB Two Stage unit and Unit AB is the Lead in sequencing Brackets indicate Lead Stage e Unit is de energized Th
23. am Run Switch must be set to Program The switch is located under the Enclosure Wiring Cover for security The Enclosure Wiring Cover can be securely closed using a padlock PROGRAM oO RUN SEASON CAUTION Winter Summer Default Winter DO NOT turn power off to the S8 Button MENU Season when in off season or season is When in Summer and in Heating Mode the S8 will turn all boiler relays off However over If you do so the battery a DHW call will bring boilers back on if needed The Message Display Line will display will run down and will have to On ther other hand in Cooling Mode the S8 will turn all boiler Fols off be replaced Instead switch to when it is in Winter setting The Message Display Line will show Summer or Winter e When in Winter the S8 will activate the Sys relay whenever the Outdoor femenil falls to or below the Outdoor Cutoff setting in heating applications In addition 1t will begin heating whenever the System temperature falls below the Set Point Temperature The Message Display Line will not display any season information However in Cooling all stages will be off and the Message Display Line will display ii When the season is over it is a good practice to switch the S8 Season setting This allow DHW calls in heating to operate the boilers when needed RESET RATIO Custom 1 8 00 OD 1 00 Sys to 12 4 00 OD 1 00 Sys Default 1 1 00 0D 1 00 Sys Button MENU Outdo
24. chedules Button MENU System Startup gt Setback Mode e The S8 can either utilize its built in day schedule or an external dry contact signal to switch to Setback e If Day Night Schedules is selected The Setback will follow the Day Night Schedule and Shutdown Setback input terminals 35 and 36 will be used as Shutdown only The External Signal will allow the Shutdown Setback input terminals 35 and 36 to work as an input for Setback No Shutdown input will be available in this scenario Page 18 LAARS Heating Systems BURNER TYPE On Off 2 Stage 3 Stage 4 Stage Default On Off Button MENU System Startup gt Burner Type S8 can sequence from a single stage and up to four stages per heating or cooling unit BOILER OUTPUT None Pump Valve Default None Button MENU System Startup gt Boiler Output When None is selected the S8 will sequence multiple heating or cooling units without any additional unit pumps or valves The Pump option allows the S8 to control the cooling or heating unit stages in addition to the unit pumps The stage pump will run for the Run On delay after the lower stage of that unit has de energized e The Valve optional functions similar to the pump option except that when all stages are off and after Run On delay has elapsed the Lead unit s valve relay will remain energized to allow for pump flow across the system The lead unit s valve will remain energized until t
25. de option from the Startup menu This feature can be used whenever it is desirable to turn off the S8 stage outputs from a remote location or another controller 1 e EMS input e When the Shutdown feature is enabled by closing a dry contact all active stages will immediately turn off The System and Comb Air and unit pumps or valves relays will remain energized for the Run On delay period and then turn off The Shutdown signal must be a dry contact only No voltage can be placed across the SHUTDOWN terminals Bring the two wires from the dry contact to the terminals marked SHUTDOWN 35 36 WIRING THE SETBACK TERMINALS 35 36 This feature can be used whenever it is desirable to switch the S8 to operate in Setback from a remote location i e EMS input or external time clock It will only be available when External Signal are selected as the Setback Mode option from the Startup menu e When the Setback is enabled by closing a dry contact the Target will change by the Setback value That is in Heating the Target will be reduced by the Setback value On the other hand in Cooling the Setback will be added to the Target Set Point 5 gs 5 26 B na e The Setback signal must be a dry contact only No voltage can be placed across the SETBACK terminals iB Bring the two wires from the dry contact to the terminals marked SETBACK 35 36 BE WIRING THE PROVE TERMINALS 37 38 The Prove feature is provided to check s
26. e The S8 will control all boilers to hold either the Set Point temperature or the Minimum Target whichever is higher The Minimum Target must be at least 20 F lower than the Maximum Target See next setting MAXIMUM TARGET Adjustable 90 F 32 C 240 116 Default 240 F 116 C Button MENU lt Outdoor Reset gt Max Target in Outdoor Reset only e This is the highest temperature heating water the S8 will circulate through the heating system e When using a radiation system it should be set according to the tubing or floor manufacturer s specification The Maximum Target must be at least 20 F higher than the Minimum Target See previous setting BOILER MINIMUM RETURN Wh monitoring the Target temperature TGT System temperature SYS Minimum Return and actual return RTN When the S8 predicts that a low return will occur it will increase the Target automatically as an effort to increase the return temperature MINIMUM RETURN Adjustable Off 80 27 140 F 60 C Default 120 F 49 C Button MENU Min Return in Heating only e The Minimum Return is the critical temperature at which the return should be above Normally this setting is provided by the boiler manufacturer or the system engineer e The S8 will use that value as a guide It will start to add additional stages if it buda that the RTN temperature will drop below the Min Return During that period it will display i in the Displa
27. e System Set Point based on outdoor temperature Or it can sequence stages to achieve an adjustable fixed Set Point in either heating or cooling j 1125 In Outdoor Reset the S8 controls a hot water heating system to provide a building with comfortable and even heat levels The S8 varies the temperature of the circulating heating water in response to changes in the outdoor temperature The heating water temperature 1s controlled through the sequencing of the stages Water Temperature in F The S8 also controls the system circulating pump with an adjustable Outdoor Cutoff In heating when the outdoor temperature is above Outdoor Cutoff the pump is off and no heating water is circulated through the system When the outdoor temperature drops below the Outdoor Cutoff the system pump relay is activated and the heating water circulates through the system The 100 60 50 m m ET 3 temperature of the heating water is controlled by the Reset Ratio Water Offset and changes Outdoor Temperature in F with Outdoor temperature In cooling applications the outdoor cutoff turns off the cooling PE c c usc s units and system pump when the outdoor temperature rises above the outdoor cutoff setting Reset Ratio Curves RESET RATIO OUTDOOR RESET 3 130 When a building is being heated heat escapes through the walls doors and windows to NS E en the colder outside air The colder the outside temperature the more heat esca
28. e an external set point from an EMS BMS system This option requires the use of the XSIG Interface CA004200 You must select the 4mA min and 20 mA max Set Points in the following screens Connect the XSIG Interface to the S8 s RS485 connection DISPLAY UNIT F C Default F Button MENU System Startup gt Display Unit e The S8 is designed to control boilers and chillers in hydronic environment where the temperature is the critical factor It allows the user of displaying temperature information and settings in either F Fahrenheit or C Celsius Select the display unit that is best suited for your application SETTING THE 4MA AND 20MA SET POINTS AVAILABLE IN 4 20MA EMS Default Normal Button MENU System Startup gt EMS 4mA Set Point EMS 20 Set Point e f EMS 4 20mA is selected from the Control Mode Menu as the temperature set point source the user must purchase a Laars XSIG Interface CA004200 to accept the 4 20mA signal and transmit it to the S8 naddition the user will need to set the temperature range parameters First set the 4mA temperature then the 20mA temperature signal that i is above or below the 4 20mA range will display the message r and all stages will de energize However the System Comb Air and Unit Pumps and Valves will continue for the Run On delay period then de energize e The control will calculate the temperature for the additional 1 9m
29. e reset function This allows the S8 to change the set point based on outdoor temperature Furthermore a customizable outdoor reset curve has been incorporated for unique applications where standard reset ratios will not satisfy In addition the following settings have been added to help fine tune all reset operation Offset Minimum and Maximum Targets and Night Setback Schedule or Setback using an External Signal STANDBY UNIT OPTION Any of the S8 heating or cooling units can be configured as a Standby with an adjustable Standby delay Assigning a specific unit to work in standby mode will remove it from the rotation In this mode the unit will be used for backup in large demand periods where the primary units will not suffice SYSTEM AND COMBUSTION AIR DAMPER OUTPUTS WITH PROVE INPUT These outputs work with the control logic to operate a primary system pump and a combustion air damper In addition a System Prove input can be wired in to check the status of either of the components activated by the outputs before stages can be activated NORMAL OR PARALLEL LO LO HI HI SEQUENCING The S8 can sequence heating or cooling units as needed For heating systems where higher efficiency is achieved using lower firing stages the S8 offers the Parallel Sequencing option It will sequence all the low firing stages first before bringing the rest of the stages on For other types of heating and cooling units using the Normal Sequencing option will bring the
30. e unit Mode is set to Auto STB Unit is set to be a Standby Unit HI Unit highest stage is active The unit Mode is set to either Auto or Standby MED Unit Middle stage is active Available in Three stage units only The unit Mode is set to either Auto or Standby MHI Unit Middle High stage is active Available in Four stage units only The unit Mode is set to either Auto or Standby e MLO Unit Middle Low stage is active Available in Four stage units only The unit Mode is set to either Auto or Standby LO Unit Lowest stage 15 active The unit Mode is set to either Auto or Standby ON Unit Stages are set to ON OFF All Unit Stages are set to OFF or unit does not exist C E Unit on Extension panel is not communicating back to the S8 c Unit Pumps are being controlled by the S8 e x Unit Valves are being controlled by the S8 DISPLAY MESSAGES The S8 normal display layout reserved the second line for message indications The following is a list of the most common Message Display Line information Summer The control is set to Summer No heat is active Winter The control is set to Winter No cooling is active Outdoor Cutoff The Outdoor temperature is above the Outdoor Cutoff in heating or below it in cooling e Shutdown Active The Shutdown Terminals are Shorted No heating or cooling units will be active e Shutdown by EMS The EMS is below 2mA or above 22mA e DHW Call 171 There is a DHW Domestic Hot Wa
31. ear round reduce the Offset e Unit Mode Settings The S8 will only sequence boilers their mode is set to Auto or Standby Check to see if any boiler stage is set to On e Control Settings The Last Stage Hold will allow only the Lead boiler to stay on for an additional number of degrees If the setting is too high and only the Lead boiler 15 on the system can over heat Reduce the Last Stage Hold setting Too Little Heat Check if the control has any of the following e Reset Ratio and Offset If reduced heat occurs only in certain weather conditions adjust the Reset Ratio and Offset See Understanding Operating Concept If reduced heat occurs year round increase the Offset e Setback and Day Night Schedule If reduced heat occurs only during specific hours check the Day Night Schedule and the Setback Boost and Boost Period values Either reduce the Setback or Boost settings or change the Day and Night Schedules e Boiler Mode Settings The S8 will only modulate boilers their mode is set to Auto or Standby Check if any boiler stage is set to Off or Standby Units are Short Cycling e Minimum Runtime Increase the Minimum Runtime only if all units tend to short cycle e Last Stage Hold Increase the Last Stage Hold only if the lead unit tends to short cycle System is Overshooting or Undershooting Page 31 Temperature Sensor Chart TEMPERATURE in Degrees F Value in Ohms 117720 82823 59076
32. ect to the S8 Use the other port to connect to the second extension or XSIG Interface Additional compatible devices can utilize the second RS485 connection on the second S8 Extension i e XSIG Interface CA004200 to provide a 4 20mA set point signal to the S8 SELECTING THE S8EXT PANEL LETTER e The S8 is capable of communicating to two SSEXTs However each extension must be identified PW Next e as either A or B using the switch on each extension to avoid having communication problem EE e Extension A Switch is set to A will operate stages I through P While Extension B Switch is set to B will operate stages Q through X Connecting S8 to Two Extension Panels and XSIG Interface using RS485 S8EXT A E zm ETE EISE ECC 6 Pin Phone Cable provided with Extension S8EXT B XSIG 4 20mA EMS Interface Comm Power 144852 O 4 20 mA EMS H2 INPUT PWR af aK ap amaj aje LIN 4 20mA 6 Pin Phone Cable provided with XSIG Interface EMS Signal Page 16 LAARS Heating Systems STARTUP SETTINGS CAUTION A good practice after performing any Startup menu modifications is to check all operating settings and adjustments to match the new settings PROGRAM CHANGE SETTINGS To be able to change the S8 settings the Program Run Switch must be
33. erature is above the Outdoor Cutoff A IMPORTANT A DHW call can be initiated by either a dry contact or using a Laars Sensor CA002400 or equivalent for immersion in a 3 8ID well CA002500 or equivalent The use of a sensor will allow the adjustment of DHW Set Point and DHW Differential DHW PUMP OUTPUT No Yes Default No Button MENU System Startup gt DHW Pump Output S8 can control the operation of the DHW Pump This option allows the user to select if the S8 should be controlling the DHW Pump or not COMBUSTION AIR DAMPER OUTPUT No Yes Default No Button MENU System Startup gt Comb Air Output e The S8 can control the operation of the Combustion Air Damper This option allows the user to select if the S8 should be controlling the Combustion Air Damper or not If Yes is selected the S8 will energize the Comb Air relay whenever there is a call fore a id and the Prove i to check on the status of the Combustion Air Damper In a failure situation the message HL pgp ha will display when there is a call for a boiler stage until Prove is Shorted i Prove fails after boiler stages where energized the stages will de energize and the message will display until situation is rectified If No is selected the Prove input will be used to check System status instead of the Combustion Air Damper SETBACK MODE Day Night Schedules External Signal Default Day Night S
34. ery 24 hours thereafter e If First On First Off FOFO is selected the concept will follow this example If A is the Lead the starting sequence will be A B then C When the de energizing of the stages starts it will turn off A B Then C Then stage D will be the new lead for the next load SETBACK SCHEDULE Button MENU System Settings gt lt Stage Settings gt lt Setback Schedule This menu provide the Day Night Schedule as well as the Setback and Boost settings SETBACK Adjustable 0 F 0 C to 80 F 44 C Default 0 0 Button MENU System Settings Setback Schedule gt Setback in Day Night Schedule Button MENU System Settings Setback in External Signal e The Setback feature can be used to provide the S8 with a lower temperature Set Point in Heating or a higher Set Point in Cooling when less load is required e For example if in heating the calculated temperature is 180 F and the Setback is 20 F then When in Setbaek ihes 58 will Bold a Set Point of 160 F The new Set Point will appear on the main display indicating this condition LEE e Atypical use for Setback is to provide less system temperature in heating to a building during the or on Wwebitends when building is not occupied but heat is still required e After selecting a value in Setback you ll be directed to the Boost menu BOOST Adjustable 0 F 0 C to 80 F 44 C Default 0 F 0 C Button MENU System Settings
35. ge the S8 settings the Program Run Switch must be set to Program The switch is located under the Enclosure Wiring Cover for security The Enclosure Wiring Cover can be securely closed using a padlock MODE Auto Standby Off On Default Auto Button BOILER Mode S8 only controls any unit set to Auto or after a delay those set to Standby None of the other settings is recommended for output units connected to active units Any output without an active unit connected must be set to Off following list describes the MODE options Auto The S8 will control the unit s operation to maintain the desired Set Point Only units set to Auto can be Lead Standby Standby units can only be activated when all units in Auto have been at HI for an adjustable Standby delay period Standby is generally used when you want a specific unit to be available in extreme load conditions Note that a Standby unit Cannot be a Lead unit Standby Time is only available in PID mode Off Any output unit A through D not connected to a physical unit should be set to Off The Off Mode can also be used to disable units that are being serviced The number of units and their stages are selected in the Startup menu On The On Mode should only be used when testing a unit The On Mode overrides the PROVE input Once set to On the unit will immediately start all of its stages RUNTIME Clear Button BOILER RunTime The RunTime provides an accu
36. gs 2 2 Amp inductive at 120 VAC 60 Hz Add On S8EXT Panels up two S8EXT Panels using RS485 Temperature Display 7 Fahrenheit or Celsius Displays Xu ds teers oe ar EEE ARA 4 Graphical Alphanumeric 7 rows x 21 char each Temperature Sensor 35 F 37 C to 250 F 121 C Outdoor Cutoff Range 20 F 7 C to 100 F 38 C ON and OFF Set POW xu ocu ox xx oe ERE eR ERE EK CRE ER DOR SEES X E 10 F 23 C to 230 F 110 C External Set PoiMt 10 F 23 C to 240 F 116 C using XSIG Interface optional Reset Ratio Range Outdoor Reset Only 8 1 to 1 4 Outdoor System Water and Custom Reset Ratio Offset Adjustment Outdoor Reset Only 2 40 F 22 C to plus 40 F 22 C Minimum Target Outdoor Reset 70 F 21 C to 170 77 Maximum Target Outdoor Reset Only 90 F 32 C to 240 F 116 C Reaction Time PID 1 to 10 minutes Minimum Run Time 1 to 60 minutes Purge Delay PID only 2 0 0 to 10 0 minutes Last Stage Hold PID only 0 F 0 C to 30 F 17 C Throttle Range OSS only ee 2 F 1 C to 20 F 11 C Domestic Hot Water Priority Options Paral
37. h can not easily be isolated from the system eee SENSOR INSTALLATION Only use the Laars sensor included with the unit Locate the sensor in the shade on the north side of the building The sensor sensor Clip ET should never be in direct sunlight Outdoor Sensor e Be sure the location is away from doors windows exhaust fans vents or other possible heat sources sensor should be mounted approximately 10 feet above ground level Mount the sensor clip base to the outside of the building Insert the sensor in the middle and snap close the clip on the sensor e sensor wires be extended up to 500 using shielded 2 conductor cable m Do not ground the shield at the sensor but at the control using the terminal marked with an O E Do not run sensor wires in conduit with line voltage wiring id as E WARNING The S8 is an operating control only All equipment must have all safety and limit controls required by code It is the responsibility of the installer to verify that all the safety and limits are working properly before the S8 is installed Low Voltage Sensor Wires CAUTION Determining the proper location for the Outdoor Sensor is very important The S8 will base its operation on the outdoor temperature information it receives from this location If the sensor is in the sun or covered with ice its reading will be different from the actual Outdoor temperature OD
38. he Outdoor temperature rises above the Outdoor Cutoff or when the Shutdown or Summer is activated TOTAL BOILERS 1 to 24 Default varies based on Burner Type and Boiler Output Button MENU System Startup gt Boiler Output This option in combination with Burner Type and Boiler Output Startup options will determine the total number of outputs the S8 will need to control f more stages are selected than the S8 and S8 Extension has the extra stages will have Li as their status STAGING Multiple Outputs Single Output Default Multiple Outputs Button MENU System Startup gt Staging Most units will require that the higher output stages to be energized after the lower output stages These units will need to select the Multiple Output option That means both Low and High Output stages must be energized for the unit to function e Some units require that when the higher output stages are required the lower stages must de energize To operate these units the user must select the Single Output option SEQUENCE Lo Hi Lo Hi Lo Lo Hi Hi Default Lo Hi Lo Hi Button MENU System Startup gt Sequencing Some units run more efficient when the lower stages are energized alone than with the higher stages These types of units should select Lo Lo Hi Hi Then the S8 will sequence the lower stages of all Automatic units before sequencing the higher stages For J stage of the same unit Then when more stages are
39. he S8 will energize the DHW Pump whenever there is a call for DHW using a dry contact or when the DHW temp falls below the DHW Set Point and DHW Differential The DHW Pump output is Normally Open N O dry contact only It does not source any power Class 1 voltages must enter the enclosure through a different opening from any Class 2 voltage wiring The S8 can control the Combustion Air Damper when the Comb Air Output option is activated in the Startup Menu WIRING THE STAGES TERMINALS 3 TO 17 The S8 can be configured to operate the stages of the heating or cooling units Moreover it can be configured to operate the unit pumps or valves in addition to the unit stages The S8 will energize the Combustion Air Damper relay whenever there is a call to energize any of the unit stages The Comb Air output has one Normally Open N O dry contact relay It does not source any power Comb Class 1 voltages must enter the enclosure through a different opening from any Class 2 voltage wiring Air In this scenario the Prove input will be used to check on the Combustion Air Damper status Damper The N O contacts are dry contacts only They do not source any voltage Wire the N O relay contacts in series with the unit s limit circuit Class 1 voltages must enter the enclosure through a different opening from any Class 2 voltage wiring Lo Hi Lo Hi Unit Unit2 WIRING THE STAGE OUTPUTS Stages Stages WIRING THE PUMP OR VA
40. he Set Point and so on with one extra stage being turned on for every throttling below the Set Point the System temperature reaches Stages will be turned off as the temperature rises toward the Set Point with one full throttling range as a differential The last stage to be turned off will be allowed to exceed the Set Point by a full throttling range before it is turned off This helps to prevent the last stage from short cycling when the load is low or when the stage is oversized Throttling Example in Heating Mode Set Point 180 F Throttling 5 F 4 Boiler Stages A B C and D wer weemmm None mee _ L3 EMI uer woe 165 F 180 3 THR 160 F 180 4 THR LEAD SETTINGS Button MENU System Settings gt lt Stage Settings gt lt Lead Settings gt The lead menu is to help in setting the Lead unit and type of rotation approperiate for the system LAARS Sequencing Controls S8 amp S8EXT Page 25 LEAD BOILER Valve stages Depending on the number of stages Default The first set of stages we DERE Button MENU System Settings gt lt Stage Settings gt lt Lead Setting gt Rotate Mode e The Lead Unit s lowest stage will always be the first stage brought on when there is a call for output As more output is needed additional Stages are added The Lead Unit is always shown on the main display in brackets e na2 Stage system see Boiler Type in the Startup sectio
41. he adjustable Outdoor Cutoff temperature the S8 will control and sequence the boiler stages to hold the calculated temperature e When the outdoor temperature rises to the Outdoor Cutoff plus a 2 F differential the S8 will turn all boilers off The System relay and any other Pump or valve relays that were energized will remain energized for the Run On delay n Cooling applications when the outdoor temperature rises to the adjustable Outdoor Cutoff temperature the S8 will control and sequence the cooling unit stages to hold the calculated temperature e Outdoor Cutoff can be set to ON or OFF In the ON position the System Relay will run regardless of the Outdoor temperature and the burner stages will be active to hold the calculated water temperature Inthe OFF position the system pump will always be off and all stages will be off as well TARGET OFFSET Adjustable from 40 F 22 C 40 F 22 C Default 0 F 0 C Button MENU Outdoor Reset gt Offset in Outdoor Reset only e Offset setting lets you adjust the starting points of the Reset Ratio curves This means that regardless of the Outdoor temperature or the Reset Ratio that has been selected when the Offset setting is changed that change is directly added to or subtracted from the calculated temperature For example if the Set Point temperature was 130 F and the Offset was changed from 0 to 10 an increase of 10 then the Set Point temperature would increase
42. he sensor wires can be extended up to 500 using shielded 2 conductor cable Belden 8760 or equivalent Temperature sensors have no polarity Connect the wires from the outdoor sensor to the S8 terminals marked OUTDOOR TEMP 31 32 e Connect the shield to the circled terminal 32 with one of the sensor wires Line Neutral SYSTEM NEN TEMP E Sensor Shiled Sensor Shiled Sensor Shiled Page 10 LAARS Heating Systems WIRING THE DOMESTIC HOT WATER DHW SENSOR TERMINALS 33 34 DHW can be used to raise system Set Point to 200 F or Maximum Target whichever is lower DHW Piping concept must be selected in the Startup Menu to determine the DHW Priority options e DHW Call terminals can be either a dry contact N O or a temperature sensor that can be purchased separately CA002400 or equivalent for immersion in a 3 8ID well CA002500 or equivalent fdry contact wire an aquastat or other controls to provide closure on the DHW terminals The sensor wires can be extended up to 500 using shielded 2 conductor cable Belden 8760 or equivalent Temperature sensors have no polarity Connect the wires from the DHW sensor to the S8 terminals marked DHW 33 34 e Connect the shield to the circled terminal 34 with one of the sensor wires Sensor Shiled WIRING THE SHUTDOWN TERMINALS 35 36 EE This feature will only be available when Day Night Schedules are selected as the Setback Mo
43. ial Program will ease the configuration of the S8 and will give the opportunity to utilize many ofthe energy saving features and give more comfortable heat when needed The program should consist of the following e Selecting the features that your system can utilize Installation Install the Control switches and sensors e Setting the System Startup e Setting the System Settings e Setting the Stages Adjusting Reset Ratio and Water Offset In Reset Mode Only SELECTING THE SYSTEM FEATURES The S8 has been designed with Hydronic heating and cooling as the primary purpose With this in mind many of the S8 features can be utilized to ease enhance and improve your system performance Some of these features are listed in this section HEATING OR COOLING WITH MULTIPLE OR SINGLE OUTPUT AT A TIME 58 is equipped to control multiple multi stage boilers with or without pumps or valves for heating application As well it can be configured for cooling with multiple stage chillers That combined with the capability of energizing only a single stage of a multi stage cooling unit when in high demand makes the S8 versatile for many industries OUTDOOR RESET SET POINT OR EXTERNAL 4 20MA SET POINT S8 can control the System Temperature either by adjusting the calculated temperature according to the Outdoor Temperature Outdoor Reset or by maintaining an adjustable Set Point The Outdoor Reset option uses an Outdoor Sensor
44. ill vary the system Set Point based on outdoor temperature Whether in Set Point or Outdoor Reset modes the outdoor sensor can be used as an Outdoor Cutoff In heating the S8 will disable all Boilers when the outdoor temperature is above the adjustable Outdoor Cutoff temperature However in cooling it will disable the units when the outdoor temperature is below the Outdoor Cutoff This feature will automatically be activated when an outdoor sensor is connected e For an outdoor sensor use a Laars outdoor sensor CA002400 or equivalent e The sensor wires can be extended up to 500 using shielded 2 conductor cable Belden 8760 or equivalent Temperature sensors have no polarity Connect the wires from the outdoor sensor to the S8 terminals marked OUTDOOR TEMP 29 30 e Connect the shield to the circled terminal 30 with one of the sensor wires RETURN SENSOR WIRING TERMINALS 31 32 OPTIONAL AVAILABLE IN HEATING ONLY Ifthe Return Sensor is connected must be purchased separately the S8 will recognize it and alternate its temperature on the display with the Target temperature If the Return is below the Minimum Return the S8 will sequence stages based on the Return Sensor Minimum Return Calculated Target and the actual System Temperature e The Return on the S8 is designed to be connected to a temperature sensor that can be purchased separately CA002400 or equivalent for immersion in a 3 8ID well CA002500 or equivalent T
45. ing Cover seals the wires from the external environment It has two screws to hold it the base and a hole to secure a lock on the wiring enclosure A plastic web that separates the wiring chamber into high and low volt sections has been provided MOUNTING THE ENCLOSURE Select a location near the equipment to be controlled e The surface should be flat and be sufficiently wide and strong to hold the S8 or S8EXT e Keep the control away from extreme heat cold or humidity Ambient Mounting Base operating temperature is from 20 to 120 F e Remove the Enclosure Wiring Cover from the control enclosure by removing the two bottom screws Remove the Enclosure Display Module by removing the middle screws e Screw the Enclosure Base to the surface through the upper and lower mounting holes on the back of the enclosure e Replace the Enclosure Display Module and replace the middle screws Do not replace the enclosure wiring cover until all wiring is done When purchasing a padlock for the enclosure the maximum shank diameter should not exceed 1 4 Enclosure Display Module Enclosure Wiring Cover Enclosure Base Hole for optional Padlock not supplied Display Mounting Screws Wiring Cover Mounting Screws Page 8 LAARS Heating Systems STALL TH E S E N SO RS Immersion Heating System Sensor Immersion Well 3 8 ID 1 2 NPT Common Supply Pipe SYSTEM SENSOR INSTALLATION LOCATING TH
46. lel Piping with Priority or without Priority and Primary Secondary Pump Run On 0 0 to 60 minutes Pump Exercise 0 Yes or No Sehedules toon Eos ar RASA O ee ee 1 Day and 1 Night Setback settings per day Night Setback 0 0 0 to 80 F 44 C Power Backup Lithium coin battery 100 days minimum 5 year replacement Maintains Clock in power outages External Inputs 2 Shutdown Input and Prove Input Dry Contacts Only Season O Winter and Summer S8EXT Specifications Extension Numbering 7 Toggle Switch A or B LED 1 Power Dual Color Green A Red B 1 Communication 8 Stage Output relays Dual Color Green A Red Stage Outputs 0 8 N O S P S T Output Relay Ratings 2 2 Amp inductive at 120 VAC 60 Hz Connection to S8 and another SSEXT Two RS485 LAARS Sequencing Controls S8 8 S8EXT Page 35 LAARS Heating Systems 800 900 9276 Fax 800 559 1583 Customer Service Service Advisors 20 Industrial Way Rochester NH 03867 603 335 6300 Fax 603 335 3355 1869 Sismet Road Mississauga Ontario Canada LAW 1W8 905 238 0100 Fax 905 366 0130 Heating Systems Company A subsidiary of BRADFORD WHITE Corporation www Laars com Litho in U S A O Laars Heating Systems 0806 Document 4213 HTC 059065 00 Rev A
47. lower operating stage followed by the higher one of the lead unit Then will do the same with the lag unit MULTIPLE OR SINGLE STAGING Unlike many boilers water heaters where to fire a multi stage boiler both low and high stage relays must be energized some of the available cooling units require that the operation of the higher stages turn off the lower operating stages This can be achieved by selecting Single from the Startup Staging menu ADD UP TO 16 STAGES As a stand alone the S8 is designed to control eight stages However it has the capability of expanding its control to two extension panels each with eight stages Thus the S8 can control a total of up to 24 stages MONITOR SYSTEM RETURN TEMPERATURE Using a smart algorithm the S8 can monitor boiler return temperature using an optional return sensor mounted on the return line Then sequence the boilers to raise above an adjustable Minimum Return DHW PUMP CONTROL WITH MULTIPLE PRIORITY OPTIONS Having a DHW input either as a dry contact to be used with an external aquastat or as a temperature sensor that can be ordered separately the S8 can control a DHW pump using its built in output relay The user will have different priority options that varies based on the DHW piping design LAARS Sequencing Controls S8 8 S8EXT Page 5 UNDERSTANDING OPERATION CONCEPT 1 4 1 3 1 1 5 20 The S8 has multiple operating modes that satisfy most hydronic systems In heating it can change th
48. mulative hourly run for the selected unit The RunTime for a specific unit can be reset to zero by pressing the middle two buttons LAARS Sequencing Controls S8 amp S8EXT TROUBLESHOOTING TEMPERATURE INPUTS Display shows Sensor OPEN Check the sensor is connected and the wires are continuous to the S8 Finally follow the procedure for Incorrect Temperature Display Display shows Sensor SHORT The S8 sees a short across the input terminals Remove the wires from the sensor terminals The display should change to read OPEN If it doesn t the S8 may be damaged Display shows an Incorrect Temperature Display Remove the wires from sensor terminals The display should change to read OPEN If it doesn t the S8 may be damaged Take an ohm reading across the detached sensor wires The ohm reading should correspond to the side chart If it doesn t the sensor may be damaged Return Sensor does not Display Temperature Check the sensor is connected and the wires are continuous to the S8 Finally follow the procedure for Incorrect temperature display CONTROL OPERATION Too Much Heat Check if the control has any of the following e Domestic Hot Water call The S8 will raise the temperature of the system to either 200 F or Maximum Target on a DHW call e Reset Ratio and Offset If excessive heat occurs only in certain weather conditions adjust the Reset Ratio and Offset See Understanding Operating Concept If excessive heat occurs y
49. n the display will show the two Lead Unit stages bracketed lt AB gt In a 3 Stage system the display will show the three Lead Unit stages bracketed lt gt and so on If Pump or Valve is selected as the Boiler Output in the Startup menu the Valve or Pump letter will be skipped from the number of stages See example to the right The missing stage C and F represent the Unit Valve or Pump The Lead Unit can be rotated based on the Rotation Mode selected See next setting with Pump or Valve stages ROTATE MODE Adjustable Time 1 hr to 999 hrs Manual FOFO Default Time 24Hours Button MENU System Settings gt lt Stage Settings gt lt Lead Setting gt Rotate Mode e The Lead Unit is the first unit brought on when output is required The Lead Unit can be rotated automatically manually or based on First On First Off FOFO The automatic rotation is recommended for most applications The current Lead Unit is shown in brackets on the main display e Only units which are set to Auto Mode can be Lead Therefore not all the units may be available when manually selecting a new Lead Unit If Time is selected a second screen will allow the adjustment of the Auto Rotate Period If 24 Hours default setting was selected the first rotation will take effect after 12 hours if the Time was not set However if the Time was set the rotation will always take place at 2 00AM The following rotations will take place ev
50. ngs Stage Settings Standby Delay e Last Stage Hold SELECT Settings System Settings Stage Settings Last Stage Hold When Oversize OSS is Selected the following are the settings that directly affects this modes operation Throttle SELECT Settings System Settings Stage Settings Throttle SENSOR FAULT Stages On Stages Off Default Stages On Button MENU System Startup gt Sensor Fault The Sensor Fault will determine the operating status of all output stages that are set to Auto when a sensor reads Short or Open RESET MODE e When Stages On is selected the S8 will turn all unit stages On when the System reads Short or Open and Outdoor is below Outdoor Cutoff in heating or above Outdoor Cutoff in Cooling When Outdoor reads Short or Open the S8 will change the Target to me the Maximum Target e When Stages Off is selected the S8 will turn all stages Off when the System reads Short or Open However when the Outdoor reads Short or Open the S8 will change the Target to me the Minimum Target SET POINT MODE When Stages On is selected the S8 will turn all stages On when the System sensor reads Short or Open e When Stages Off is selected the S8 will turn all stages Off when the System sensor reads Short or Open The Outdoor Sensor Short or Open status will not affect the control operation in Set Point mode Page 20 LAARS Heating Systems OPERATING SETTINGS PROGRAM CHANGE SETTINGS To be able to change the S8 settings the Progr
51. of heat or cool The Day level is used when a building is occupied and people are active e The Night Setback level is used when a building is not occupied or when people are sleeping This setting reduces the calculated temperature in Heating and increase it in Cooling by the Setback setting In Heating if the Day calculated water temperature was 150 F and the Setback was 20 F the Night Schedule will run at 150 F 20 F 130 F e Ifthe Boost feature is being used it uses the Day Schedule as a Boost ending point That is if the Day Schedule is set to start at 6 00AM the Boost was set to 10 F and the Boost Period was 30 minutes the Boost will start at 5 30AM The S8 will then raise the calculated water temperature by the Boost amount Using the previous example at 5 30AM the S8 will raise the calculated water to 160 F 150 F 10 F until 6 00AM SET PRESENT TIME Button MENU System Settings gt lt Setback Schedule gt Present Time Button MENU KMaintenance gt Present Time The Time is used for Day Night Schedule and History graph e Adjust the time by selecting Time from the menu and then scrolling through the hours followed by the minutes If hours are to be set to PM scroll through the AM hours to reach the PM hours CAUTION Remember that the battery is the backup for the Time If no power is supplied to the S8 and there was no battery or battery had no power time values will be lost and will need to be
52. or Reset gt Reset Ratio In Outdoor Reset Only e The Reset Ratio applies only to Heating applications e The Reset Ratio determines how the System water temperature will vary with Outside temperature With any of the ratios the colder it becomes outside the hotter the temperature of the system water See Understanding Operation Concept on page 5 e With a 1 00 OD 4 00 SYS ratio the System water temperature SYS will increase rapidly as the outside temperature falls hitting the Maximum of 240 F at 35 F outside temperature With a 4 00 OD 1 00 SYS ratio the System water temperature SYS will increase slowly as the outside temperature falls Even at 30 F the system water will only be 125 F and at 22 F outside the system water will be 112 F Such a low Reset Ratio might be used with radiant floor heating applications With most baseboard heating applications a 1 00 OD 1 00 SYS setting is a good place to start With a 1 00 OD 1 00 SYS ratio for every degree the outside temperature falls the system water temperature is increased one degree frequired Adjust the RESET RATIO in cold weather If the ambient building temperatures are too cold in cold weather move the ratio to a higher selection That is if 1 00 OD 1 00 SYS was initially selected change the selection to 1 00 OD 1 25 SYS If the building temperatures are too warm in cold weather move the ratio to a lower selection That is if 1 00 OD 1 00
53. pes If you Bs EET 5 can input heat into the building at the same rate that it is lost out of the building then the 100 water Temperature 3 110 building temperatures will remain constant The Reset Ratio is an adjustment that lets you achieve this equilibrium between heat input and heat loss 100 UT cas Outdoor Temperature The starting point for most systems 1s the 1 00 OD 1 00 SYS Outdoor Temperature Heating Water Temperature ratio This means that for every degree the outdoor L 110 14 1 1 temperature drops the temperature of the heating water will increase one degree The E starting point of the curves is adjustable but comes factory selected at 70 F Outdoor With a 20 Offset the E 100 Temp and 100 F Water Temp For example with a 1 00 OD 1 00 SYS ratio if the ratio curves gle A 2 A 80 Water Temperature 2 9 outdoor temperature is 50 F this means the temperature has fallen 20 from the starting E 20 Offset 4 4 point of 70 F Therefore the heating water temperature will increase 20 to 120 F E sx 70 60 50 40 Outdoor Temperature Each building has different heat loss characteristics very well insulated building will not lose much heat to the outside air and may need a Reset Ratio of 2 00 OD 1 00 o d m SYS Outdoor Water This means the outdoor temperature would have to drop 2 a degrees to increase the water temperature 1 degree On the other hand a poorly insulated _ 2 n building with ins
54. re is above the Outdoor Cutoff only the DHW Pump relay will energize DHW SET POINT REQUIRES AN OPTIONAL DHW TEMPERATURE patada Adjustable 100 F 38 C to 200 F 93 C Default 160 F 71 C Button MENU System Settings gt lt DHW Settings gt DHW Set Point This is the desired DHW temperature setting at which the DHW Pump relay will de energize when reached S8 can accept a DHW call in two ways An aquastat can provide a dry contact closure to terminals 33 and 34 is the first option e The second option will be connecting a Laars temperature sensor CA002400 or equivalent for immersion in a 3 8ID well CA002500 or equivalent will offer the capability of adjusting the DHW Set Point and Differential through he S8 easy to follow menu In addition to being able to view and log DHW temperature history DHW DIFFERENTIAL Adjustable 5 F 3 C to 80 F 44 C Default 10 F 6 C Button MENU System Settings DHW Settings DHW Diff This represents the number of degrees the DHW temperature can drop from the DHW Set Point before a DHW call can be recognized and the DHW Pump relay energized Larger Differential will result in larger fluctuation in DHW temperature However small Differential will have a tighter control over the DHW temperature but might result in boilers coming on frequently for short periods to satisfy the DHW Set Point and Differential settings Page 28 LAARS Heating Systems PUMP VALVE AND
55. reset LAARS Sequencing Controls S8 amp S8EXT Page 27 DHW SETTINGS Button MENU System Settings gt lt DHW Settings e ADHW call can be initiated by shorting the DHW input terminals 33 and 34 In addition using a Laars temperature sensor on the same terminals instead of a dry contact input will add the DHW Set Point and Differential control capability In addition to raising the Target to either 200 F or the Maximum Target on a DHW call which ever is lower the S8 provides three levels of DHW pump operation The first is when Primary Secondary is selected as the DHW Piping from the Startup Menu This option will provide no DHW Priority Furthermore if there was a DHW call during the Summer or when the outdoor temperature is above the Outdoor Cutoff both the DHW Pump and the System relays will energize Upon the termination of the DHW call the DHW Pump relay will de energize leaving the System relay energized for the Run On delay The other two DHW options are available when Parallel is selected as the DHW Piping from the Startup Menu These two options will not allow the System relay to energize in the Summer or when the outdoor temperature 1s above the Outdoor Cutoff on a DHW call In Winter if the DHW Priority Timer was set to NO a DHW call will keep the System relay energized in addition to energizing the DHW Pump relay Upon termination of the DHW call the DHW Pump relay will de energize leaving the System relay on
56. rs from thermal shock and condensation caused by cool returns LAARS Sequencing Controls S8 amp S8EXT Page 7 AUTOMATIC ROTATION AMONG BOILERS e Rotating the lead unit to be activated on a call for output promotes even wear on all units The S8 has three modes of rotation Manual First On First Off or Timed Rotation This option automatically rotates units every selected time period from one hour to every 41 999 hours days SETBACK OR DAY NIGHT SCHEDULING Two Setback modes are available for the S8 The Day Night Scheduling provides an adjustable time based schedule for the Setback e The Setback mode uses an external signal to switch the operation of the S8 in and out of setback mode INSTALLATION Each of the S8 or SSEXT consists of three primary enclosure components e The Enclosure Display Module contains the display buttons LEDs and electric wiring terminals It has two screws to hold it to the base A program configuration switch used to adjust S8 settings is placed above the terminals This switch is enclosed with the enclosure wiring cover for security Wiring terminals are of the plug in type to ease installation and removal e The Enclosure Base contains the holes to mount and hold the control against the wall or any flat surface All other enclosure components mount on the base The bottom section of the Enclosure Base contains the wiring chamber with knockouts on the bottom to easy installation e The Enclosure Wir
57. s connected and the last boiler relay has de energized the SYS relay will remain energized for a period set by the Run On e stage outputs will be activated until the Prove input is shorted If a Prove is not required the factory installed jumper should remain connected LAARS Sequencing Controls S8 amp S8EXT Page 11 In Cooling applications the system relay will energize when the outdoor temperature is above the Outdoor Cutoff setting A typical use of the SYS output is to activate a system pump starter The pump can run whenever there is a call for heat cool When stages are no longer required the pump will stay active for an adjustable Run On delay System Output Operation in Reset Mode The SYS output relay will energize whenever the outdoor temperature is below the Outdoor Cutoff The SYS will remain constantly energized while the outdoor temperature is below the Outdoor Cutoff When the outdoor temperature rises 2 F above the Outdoor Cutoff the SYS output will remain energized for the period set by the System Run On The SYS output has one Normally Open N O relay that acts as a dry contact only It does not source any power Class 1 voltages must enter the enclosure through a different opening from any Class 2 voltage wiring WIRING THE DHW PUMP TERMINALS 21 22 The S8 can control the DHW Pump when the DHW Pump Output option is activated in the Startup Menu WIRING THE COMBUSTION AIR DAMPER TERMINALS 23 24 T
58. set to 30 minutes the Boost will start at 6 30Am and terminate at 7 00Am Avoiding Conflicting Boiler Limits The temperature limits set on the boilers MUST be set considerably higher than the S8 s WARNING Set Point for the reasons detailed below The temperature limits set e S8 sensor is located in a common header some distance from the boilers on the boilers must be higher As the temperature rises in the header and before reaching the sensor location energy is than the S8 Set Point Read dissipated Therefore the temperature in the header could be lower than that registered the section at left for details by boiler sensors that will prevent erratic system e In addition to the normal drop experienced between the boiler s temperature and that operation read by the S8 sensor the Last Stage Hold setting must be accounted for The boiler limit must be set above the Set Point PLUS the Last Stage Hold PLUS the normal drop experienced in the piping Using the previous example of a 10 F Last Stage Hold with a 160 F Set Point the boilers limits must be set enough over 170 F to prevent the boilers internal limits being reached In this situation the boiler high limit should be set at approximately 180 F to prevent the difference in boiler temperature vs header temperature causing erratic operation DAY NIGHT SCHEDULES Button MENU System Settings Setback Schedule gt Day Schedules e S8 has two levels
59. tage Settings gt Min Runtime PID Logic only This is the minimum amount of time any stage will run Forthe lowest stage of a unit the Minimum Runtime starts after the purge cycle e Initially set the Min Runtime to half the Reaction Time If System tends to overshoot reduce the Min Runtime If boilers tends to short cycle increase Min Runtime STANDBY DELAY Adjustable 1 60 minutes Default 10 minutes Button MENU System Settings gt lt Stage Settings gt Standby Delay in PID Logic only e The Standby Delay Time only applies to units in Standby Mode e AStandby unit can only be activated after all the units in Auto Mode have run for the full Standby Time Page 24 LAARS Heating Systems Standby units are used for backup or extreme load conditions only A Standby Stage can never be a Lead Stage The full Standby Delay Time must always elapse regardless of what happens to system temperature Therefore shorter Standby Times will result in smoother set point operation in extreme conditions Longer Standby Times may prevent a Standby unit from starting if the other units can eventually meet the load or if the load decreases When setting Standby Time remember that it will be added to the Reaction Time for the first stage on the first Standby unit The following stages start time will rely on Pre Purge and Reaction Time LAST STAGE HOLD Adjustable 0 F 0 C 30 F 17 C Default 5 F 3 C Button MENU Sys
60. tem Settings gt lt Stage Settings gt Last Stage Hold in PID Logic only The Last Stage Hold prevents short cycling of the Lead Stage during low load conditions where the system might have a load that is significantly less than the output of one stage When the S8 brings on the Lead Stage the Set Point is quickly exceeded and the Lead Stage is turned off To prolong the run time during this type of condition use the Last Stage Hold setting In heating the S8 will allow the system temperature to exceed the Set Point by the number of degrees selected before the Lead Stage is turned off In cooling the the S8 will allow the system temperature to rise above the Set Point by the number of degrees selected before the Lead Stage is turned off e For example with a Set Point of 160 F and a Last Stage Hold setting of 10 F the Lead Stage boiler will remain on at low fire until the Set Point reaches 170 F then turn off THROTTLE RANGE Adjustable 2 F 1 C 20 F 11 C Default 2 F 1 C Button MENU System Settings gt lt Stage Settings gt Throttle in OSS Logic only The Throttling Range sets a temperature band around the Set Point that controls when stages will be turned on or off Forexample in the Oversize OSS heating mode no stages will be activated until the temperature falls one full Throttling Range below the Set Point A second stage will be activated when the temperature falls to two full Throttling Ranges below t
61. ter call The S8 will Raise system Set Point to the indicated temperature DHW increases calculated temperature to 200 F or Max Water Temperature whichever is lower Page 30 LAARS Heating Systems e Holding Return at 110 F The Return sensor is reading less than the Minimum Return S8 is trying to raise return to 110 F e Holding Until 150 F The Lead boiler is in Last Stage Hold This example shows that the lead stage will turn off when system temperature reaches 150 e Waiting for Comb Prove The System or Combustion Air Damper relay is ON and the prove terminals are open before the lead boiler relay can energize e SYS Prove Failure After boilers have run for a while Prove signal was opened The boiler relays will de energize However the System relay will remain energized STAGE SETTINGS Button BOILER In most installations all active unit adjustments are the same but each can be configured differently if desired When the BOILER or C UNIT button is depressed the Unit A Settings menu will be shown Make all the appropriate settings for Unit A See below Then select the Next Stage option from the menu to bring up the Boiler B Settings menu and make all the settings Continue until all boilers have been set eu e Ifa SSEXT is connected to the S8 scrolling through stages using the Next and Prev Stage menu options will scroll through the S8EXT stages as well A CAUTION To be able to chan
62. to 140 F Page 22 LAARS Heating Systems e The Offset setting does not change the ratio selection For instance with 1 00 OD 1 00 SYS Reset Ratio the System water temperature will always increase one degree for each degree change in the Outdoor temperature What the Offset does is add or subtract a constant temperature value See Understanding Operation Concept on page 5 e The Minimum and Maximum Target will take precedence over the Offset That is if the Max Target was set to 180 F and the Offset was set to 20 F If the set point was 170 F the new calculated set point based with the Offset will not exceed 180 F e frequired Adjust the Water Offset in mild weather If the ambient building temperatures too warm in the mild weather decrease the Target Offset If the ambient building temperatures are too cold in the mild weather increase the Target Offset The rule of thumb for baseboard radiation is to change the Offset 4 F for every 1 F you wish to change the building temperatures In radiant heat applications change the Offset 1 F or 2 F for every 1 F you wish to change the building temperature MINIMUM TARGET Adjustable 70 F 21 C 180 F 82 C Default 120 F 49 C Button MENU Outdoor Reset gt Min Target in Outdoor Reset only The Minimum Target must be set to the boiler manufacturer s specification The S8 will calculate the Set Point based on the Outdoor temperature the Reset Ratio and the Offset valu
63. ufficient radiation may need a Reset Ratio of 1 00 OD 2 00 SYS n e p 5 This means that for each degree the outdoor temperature dropped the water temperature 120 Water Temperature 130 will increase 2 degrees The S8 has a full range of Reset Ratios to match any buildings heat loss characteristics 120 A heating curve that relies not only on Outdoor temperature but also on type of radiation will improve heat comfort The following are suggested initial settings for different types 400 of radiation based on average building insulation and heat loss The contractor can fine 70 60 50 40 j on Outdoor Te t tune these adjustments based on the specific building need Type of Radiation in Building Reset Ratio Offset Radiators Steel amp Cast Iron 1 00 OD 1 00 SYS 0 F A WARNING Baseboard Finned copper tube amp Cast Iron 1 00 OD 1 00 SYS 0 When controlling non condensing Radiant High Mass Concrete 4 00 OD 1 00 SYS 10 cd Radiant Low Mass Joists 2 00 OD 1 00 SYS 10 F manufacturer specifications In that Fan Coils amp Air Handlers 1 00 OD 1 00 SYS 20 F case system temperature must not go below such temperature Page 6 LAARS Heating Systems MAKE SURE YOU HAVE THE RIGHT CONTROL If you need the S8 to do additional tasks that either are not listed or do not know how to configure them contact LAARS INITIAL SETUP Setting an Init
64. y Message Line to indicate that the S8 1s sequencing boilers to protect the return from donne below Return Most condensing boilers will run more efficient with cooler return temperatures In this case select the Off option on the Minimum Return to allow the monitoring of the return on the display without sequencing the boiler stages RETURN LAG Adjustable 0 30 minutes Default 2 minutes Button MENU Min Return Return Lag in Heating only The Return Lag is the time it takes for the system return to change after sequencing the stages get this time start from a cold system Calculate the amount of time it takes to get the return five degrees warmer from the start of the boiler That should be your Return Lag LAARS Sequencing Controls S8 amp S8EXT Page 23 SYSTEM SETTINGS Button MENU System Settings The System Settings menu provide access to adjusting and fine tuning the system for enhanced comfort and better fuel savings The S8 behaves differently based on the selected Control Modes see Startup Settings PROGRAM CHANGE SETTINGS To be able to change the 58 settings the Program Run Switch must be set to Program The switch is located under the Enclosure Wiring Cover for security The Enclosure Wiring Cover can be securely closed using a padlock run STAGE SETTINGS Button MENU System Settings gt lt Stage Settings REACTION TIME Adjustable 1 10 minutes Default 2 minutes
65. ystem component operation before energizing the stages It can be Bei used to check on the Combustion Air Damper by connecting it to the end switch of the damper In this case the Comb Air Output option must be activated from the Startup Menu Ifthe Comb Air Damper Output option was not activated the PROVE input can be used to check on the System Output A typical use of this feature is to check for system pump flow before energizing any stage Ifthe PROVE input is open on a call the S8 will enable only the System Output All stage outputs will be off when the PROVE input is open e A factory installed jumper provides the System Prove signal Do not remove the jumper unless it will be replaced by a System Prove signal Bring the two wires from the dry contact to the terminals marked PROVE 37 38 No voltage can be placed across the PROVE terminals Prove Dry Contact WARNING The PROVE input cannot be used as a safety limit All equipment must have its own certified limit and safety controls as required by local codes No boiler stage will start unless Prove terminals are shorted DO NOT remove the PROVE jumper supplied unless replacing it with a Prove signal WIRING THE SYSTEM OUTPUT TERMINALS 19 20 ME System Output Operation in Set Point Mode In Heating the SYS output relay will energize whenever the outdoor temperature drops below the Outdoor Cutoff or whenever a stage output is active If no outdoor sensor i

Mini-MOD and Mini-Extension Installation Manual

Contents

Download Pdf Manuals

Related Search

Related Contents