User Manual - Bacharach, Inc.
Contents
1. BACI LARACH The Measurable Difference Infrared Gas Detector Installation and Operation Manual Instruction 6490 9000 June 2015 Revision 3 MGS 250 Product Leadership e Training e Service e Reliability MGS 250 Manual WARRANTY POLICY BACHARACH INC WARRANTS THIS GAS DETECTOR TO BE FREE FROM DEFECTS IN MATERIALS AND WORKMANSHIP FOR A PERIOD OF ONE YEAR FROM THE DATE OF PURCHASE BY THE ORIGINAL OWNER IF THE PRODUCT SHOULD BECOME DEFECTIVE WITHIN THIS WARRANTY PERIOD WE WILL REPAIR OR REPLACE IT AT OUR DISCRETION THE WARRANTY STATUS MAY BE AFFECTED IF THE GAS DETECTOR HAS NOT BEEN USED AND MAINTAINED PER THE INSTRUCTIONS IN THIS MANUAL OR HAS BEEN ABUSED DAMAGED OR MODIFIED IN ANY WAY THIS GAS DETECTOR IS ONLY TO BE USED FOR PURPOSES STATED HEREIN THE MANUFACTURER IS NOT LIABLE FOR AUXILIARY INTERFACED EQUIPMENT OR CONSEQUENTIAL DAMAGE DUE TO ONGOING RESEARCH DEVELOPMENT AND PRODUCT TESTING THE MANUFACTURER RESERVES THE RIGHT TO CHANGE SPECIFICATIONS WITHOUT NOTICE THE INFORMATION CONTAINED HEREIN IS BASED ON DATA CONSIDERED ACCURATE HOWEVER NO WARRANTY IS EXPRESSED OR IMPLIED REGARDING THE ACCURACY OF THIS DATA ALL GOODS MUST BE SHIPPED TO THE MANUFACTURER BY PREPAID FREIGHT ALL RETURNED GOODS MUST BE PRE AUTHORIZED BY OBTAINING A RETURN MERCHANDISE AUTHORIZATION RMA NUMBER CONTACT THE MANUFACTURER FOR A NUMBER AND PROCEDURES REQUIRED FOR PRODUCT TRANSPORT SERVICE POLICY BACHARACH INC MAI2. I button is pressed or e after Modbus register 4000 is set to 0 Baud Rate Sets the baud rate for Modbus RS 485 communications 00 9 600 baud default 01 19 200 baud Stop Bits Sets the number of stop bits required to match the controlling communications equipment e g building management system etc 01 1 stop bit default 02 2 stop bits Parity Sets Modbus parity option 00 None default 01 Odd parity 02 Even parity 6490 9000 Revision 3 37 MGS 250 Manual 38 Parameter x Description D df Analog Output Scaling A Allows the user to select the full scale PPM value that represents maximum analog output e g 20 mA for scaling the analog output Adjustment range is from 100 PPM to 3500 PPM Default 3500 PPM The setting cannot be adjusted above 3500 Use the Up and DOWN buttons to set the desired full scale value All outputs will be scaled to the indicated full scale value NOTE Alarm values are not scaled but are absolute values Setting a smaller full scale does not correspondingly scale the alarm setting NOTE When the ppm level is greater than the programmed analog output Full Scale pom P 16 the analog output will go to a 10 over range state indicating that the concentration is too high for the analog output to achieve For example for a 1 5 V setting the analog output would go to 5 5 V for 4 20 mA it would go to 22 mA and so on NOTE The analog output
3. MGS 250 Manual Adjustment Using Calibration Gas Cylinders If no further changes to the other parameters are required press and hold the button for 5 seconds to exit the Parameter list Upon exiting the parameters list the gas detector will enter offline mode for a period of 10 minutes This allows time for the calibration gas to dissipate after testing During offline mode the gas detector suppresses all outputs The display reads oFFL offline during 10 minute timeout The tolerance will limit the actual adjustment accuracy that is d NOTE All calibration gas mixtures have a blend tolerance achievable 48 6490 9000 Revision 3 MGS 250 Manual Section 7 Modbus Communications 7 1 Introduction The MGS 250 gas detector can be configured to communicate on an RS 485 network using Modbus RTU protocol Before configuring the gas detector for Modbus communications be sure your network connection is complete and your network termination switches are set appropriately Refer to Chapter 3 Wiring and Configuration for details This section details the MGS 250 parameters that can be accessed via registers of the Modbus RTU Modbus protocol Generally with the exception of some of the communications parameters parameters you can access and or configure from the front panel of the MGS 250 can also be accessed and or configured via a Building Management System for example on the same Modbus network 7 2 Com
4. 02 Selects 0 10 V 03 Selects 2 10 V 04 Selects 4 20 mA 34 6490 9000 Revision 3 MGS 250 Manual Parameter x Description D E pa Alarm ON Delays L Sets the ON delay time 0 15 minutes for the alarm output signals relay Modbus The default delay is 0 minutes Alarm OFF Delays Sets the OFF delay time for the alarm output signals relay Modbus in minutes 0 15 The default delay Is 0 minutes Relay Contact Behavior Failsafe Mode Sets the default relay power state so that power loss can be detected The behavior of the relay changes from energizing when an alarm condition occurs default to energizing at power up Failsafe In both cases the relay changes state when an alarm occurs failsafe is simply inverted This allows power failures to be detected as alarms 00 NO default mode 01 Failsafe mode Relay Latching Controls the relay latching behavior 00 OFF default Relay does not latch and resets once the alarm condition is removed 01 ON Relay remains latched reset by BMS command over RS 485 or by pressing and holding the Enter button for 5 seconds Audible Alarm The units have an internal audible alarm You can disable this but the default setting is enabled in compliance with EN378 00 OFF 01 ON default 6490 9000 Revision 3 35 MGS 250 Manual Parameter x Description m T Display Mode L The display can be turned on by using this parameter When set to ON the
5. Analog Input Registers ES EER NE bee Ee aS kaqa aska qani 50 7 A Analog Output R gisters etes ie EE se GE ER N 51 TS PSB UTE 52 TOv Output Status F castes cat GE EG kaa Ee GE Na 52 SECTION 8 TROUBLESHOOTING 53 Sl Faut Codes Ja 53 2 Diapnosties Attributes P 18 uuu EA tupas a dc een EG 55 8 3 Resetting MGS 250 to Default Values 56 8 4 Other SV MP LOIN Se 57 SECTION 9 REPLACEMENT PARTS AND ACCESSORIES 58 CE DECLARATION OF CONFORMITY 59 6 6490 9000 Revision 3 MGS 250 Manual List of Figures SECTION 1 INTRODUGETION siese ee ee n ie ae Ge Ge ee Ge 9 Figure 1 MGS 250 Components 9 Figure 2 Broadband Gas Groups 1 3 uyu u D RE a Ee ee Su 11 Figure 3 Gas Specific MGS 250 Gas Detectors 12 Figure 4 Changing Gas Types and Accuracy 14 SECTION 2 MOUNTING THE GAS DETECTOR 17 Figure 5 Initial Housing Separation 20 Figure 6 Front and Back Views of MGS 250 Base 21 SECTION 3 WIRING AND
6. Otherwise install the blanking plug d NOTE The pre installed cable gland left and optional cable 9 that is included in the mounting kit 22 6490 9000 Revision 3 MGS 250 Manual 3 2 Wiring Supply Power 24VAC or 24VDC WARNING Incorrect wiring may permanently damage the gas detector and void the warranty Double check all terminations before applying power Either 24VAC or 24VDC may be used to power the MGS 250 Connect wiring to the appropriate terminal locations see Table 5 Use 2 wires between 14 and 22 AWG Refer to Figure 8 for AC wiring left or DC wiring right 1 2 34 5 6 7 8 9 10 11 32 1 2 34 56 7 8 9 10 1112 24VAC 24VDC OUT RS485 RELAY 24VAC 24VDC OUT RS485 RELAY L N GND GND B A SH NC C NO L N GND GND B A SH NC C NO 24 VAC NEUTRAL 24 VDC 24 VDC Ground Figure 8 Supply Power Wiring Options Table 5 Power Options and Terminal Block Connections Power Option i Wiring Termination W za 24V AC neutral save L 3 24VDC positive 24V DC ground 6490 9000 Revision 3 23 MGS 250 Manual WARNING The MGS 250 must be powered by either isolated from line voltage by double insulation or e a suitable UL 60950 CSA certified power supply that is e an appropriately rated UL listed CSA Class 2 transformer Failure to comply can result in personal injury or death H WARNING Neutral polarity must be maintained across units Refer to Figure 9 120 VAC SUPPLY en ae ae oe ae e
7. 0 10 V 1 5 V 2 10 V 1 relay rated 1 A 24 VAC VDG 0 5A 125V AC UL rating Squelch Readings below 75 ppm are squelched by default Communication Baud rate 9 600 or 19 200 selectable Modbus RTU over Start bits 1 Data bits 8 RS 485 Parity None odd even programmable Stop bits 1 or 2 programmable Retry time 500 ms min time between retries End of msg Silent 3 5 characters Alarm Delay Selectable 0 to 15 minutes IP Rating Not IP rated An accessory splash shield is available for areas requiring additional protection from wash down Temperature Rating 22 to 104 F 30 to 40 C Humidity and 5 90 relative humidity non condensing Elevation 0 10 000 ft altitude Weights Dimensions 6 3 oz 4 0 x 5 5 x 1 5 180 g 102 x 140 x 37 mm ABS plastic UL flammability rating of 94V 0 Approvals CE UL CSA IEC EN 61010 1 1 When filtering is disabled see parameter P 19 on page 42 the unit will respond to concentrations sub 10 ppm 16 6490 9000 Revision 3 MGS 250 Manual Section 2 Mounting the Gas Detector 2 1 Warnings and Prerequisites WARNING Explosion hazard Do not mount the MGS 250 in an area that may contain flammable liquids vapors or aerosols Operation of any electrical equipment in such an environment constitutes a safety hazard CAUTION The MGS 250 contains sensitive electronic components that can be easily damaged Do not touch or disturb any of these component
8. Analog Output Operates normally Modbus Registers Modbus registers indicate the fault 4 5 3 Critical Faults Critical faults may indicate an unrecoverable condition Please refer to Section 8 for more information The following occurs when a critical fault condition exists Table 11 MGS 250 Behavior during a Critical Fault Item Behavior During Critical Fault State Green LED Off indicating the gas detector is off line Display Shows the appropriate fault code 32 6490 9000 Revision 3 MGS 250 Manual Section 5 Configure the Gas Detector 5 1 User Interface Overview The gas detector is configured through the built in menu system Once mounting is complete attach the gas detector to the base and apply power MGS 250 4 digit Power LED LED Display Information Enter Select Button Button Up Down Button Button Figure 14 The User Interface of the MGS 250 The user interface consists of four pushbuttons a four digit LED numeric display and a power LED When the display is off press any button to wake the display for 10 seconds Buttons functions are listed in Table 12 Table 12 Button Functions Button x Description Used to access the parameter list Used to back up one level without writing to memory when the parameter list is active Used to mute the audible alarm for the time period configured in parameter P 12 Used to increment the value or parameter displayed Used to decrement the value o
9. of the Bacharach Inc products covered by this 621 Hunt Valley Circle New Kensington PA 15068 declaration Year conformity is 2013 declared Product s Refrigerant Gas Monitor Transmitter The undersigned hereby declares that the above referenced products are in conformity with the provisions of the following standard s and is in accordance with the following directive s Directive s 2004 108 EC Electromagnetic Compatibility EMC Directive 2006 65 EC Low Voltage Directive LVD Standard s Electromagnetic compatibility electrical apparatus for the EN 50270 2006 detection and measurement of combustible gases toxic gases or oxygen Limits and methods of measurement of electromagnetic EN 55011 2007 disturbance characteristics of industrial scientific and medical ISM radio frequency equipment IEC 61010 1 2010 Safety requirements for electrical equipment for measurement control and laboratory use Part 1 General requirements EN 61010 1 2010 Signature Name Aaron Kennison Title Engineering Manager Date 3 July 2013 The technical documentation file required by this directive is maintained at the corporate headquarters of Bacharach Inc 6490 9000 Revision 3 59 Ss QUALITY NSAI Certified The Mewturable Diffewnee www MyBacharach com e helo MyBacharach com Bacharach World Headquarters USA 621 Hunt Valley Circle New Kensington PA 15068 Phone 72
10. position Do not apply force to the switch or push on the switch with any device The switch changes position up and down along the access slot direction 28 6490 9000 Revision 3 MGS 250 Manual RS 485 TERMINATOR Refrigeration or Building Controller Terminator IN Ar an bd a y IN IN j IN IN x M M M m OUT OUT OUT IN Figure 13 Setting Network Termination Resistors 3 6 Conclusion Once the base is mounted and all wiring is complete align the gas detector housing and press it onto the base The gas detector will snap into position completing all electrical connections Ensure the top and bottom snap locks are engaged IMPORTANT If the right cable gland was not needed during installation and wiring be sure to install the blanking plug IMPORTANT Do not apply caulking or other material around the gas detector base The gas detector relies on air d exchange through the spaces between the base and the gas detector housing Do not obstruct the small gap around the housing and the base with any material 6490 9000 Revision 3 29 MGS 250 Manual Section 4 Operation and Stabilization 4 1 Power Up and Warmup On powering up the MGS 250 will sense for the presence of gas after an initial warm up period of 2 to 5 minutes The green LED will flash at a 1 second interval during the warm up 4 2 Stabilization IMPORTANT It is vital when first installing the gas detector that it warms up i
11. signal range is from 100 ppm to the default value of 3500 ppm which is scaled across the actual output range selected by the analog output type d parameter P 03 The upper PPM limit is programmable using analog output scaling parameter P 16 This parameter sets the full scale PPM value creating a PPM range across which the analog output is scaled See Figure 15 for more details 6490 9000 Revision 3 MGS 250 Manual 20 mA 4 mA asuey 1Nd1NO pauyag 195N MAN Jajyawesed BUILDS 1nd1no sojeuy pauyaq sJasn 100 PPM 3500 PPM INdd OOSE O1 INdd 001 aduey JOSUAS 1 neJ q Figure 15 Analog Output Scaling Options 39 6490 9000 Revision 3 MGS 250 Manual Parameter x Description D 94 Gas Test Mode ee Places the gas detector in gas test mode 00 Disabled default 01 Enabled When enabled the display continuously cycles through the following e CAL is displayed briefly e Next the gas group number or gas type based on product code is displayed e Then four dashes are displayed After gas is applied and the 75 PPM squelch level is exceeded the live concentration replaces the four dashes See section 6 4 if using Gas Test Mode to initiate the calibration procedure NOTE To prevent false alarms all outputs are suspended while Test Mode is active The only live indication is the 4 digit display Once the gas test mode is enabled to perform a gas test or calibration th
12. test e quantified A known concentration of gas is used e non quantified A gas of unknown concentration is used Adjusting gas detector response exposes the gas detector to a calibration gas as well like a quantified bump test but additionally sets 44 6490 9000 Revision 3 MGS 250 Manual the actual gas detector response level via parameter P 17 to ensure that the gas detector activates at the specified gas concentration Refer to the following sections for addition information on bump testing and gas detector response adjustment CAUTION Before you carry out the test or adjustment e Advise occupants plant operators and supervisors e Check if the gas detector is connected to external N systems such as sprinkler systems plant shut down external sirens and beacons ventilation etc and disconnect as instructed by the customer e For bump test or calibration the MGS 250 should be powered up and fully stabilized per Section 4 6 3 Bump Testing IMPORTANT Notify others that testing is underway During bump testing the alarm outputs are active and will trigger d whatever response is intended It is the operators responsibility to ensure that such actions are acceptable and can be performed safely After installation and parameter setup see Section 5 the units should be bump tested Expose the gas detector to test gas The gas selected should be a high enough concentration to put the system into alarm and l
13. the reset option 6490 9000 Revision 3 41 MGS 250 Manual Parameter x Description Response Filtering This parameter is used to turn filtered output ON 01 or OFF 00 The default setting is ON 01 The Modbus and analog output are filtered so that responses below 75 ppm are squelched If the display mode P 09 is set to ON 01 the display shows 0 for any signal level below 75 ppm Some installations may wish to monitor the small analog output changes that may be created by the detector environment Turning filtering OFF 00 allows these small variations around the minimum analog output e g 4 mA 1V etc to be transmitted via Modbus and the analog output terminals NOTE The detector display is OFF when filtering is OFF P 09 is disabled NOTE Whenever filtering is OFF the detector display will turn ON for 10 minutes if the detector is re zeroed see Section 4 3 This is intended to aid maintenance testing The analog outputs continue to transmit the full unfiltered range and the alarm setpoint remains active NOTE If filtering is turned off 00 Analog Output Scaling P 16 should be adjusted to 500 ppm 5 3 Completing Setup To complete the setup after all parameters are set as needed simply press and hold the information button for 5 seconds to exit the Parameter list The gas detector is now actively monitoring its surroundings NOTE If no buttons are pressed for 2 minutes the MG
14. you are ready to wire the device see section 3 carefully snap the cover onto the base unit Figure 5 Initial Housing Separation 20 6490 9000 Revision 3 Cable Gland Installed MGS 250 Manual Flat Surface Mounting Holes 6 Places NOTE Use 6 screw or smaller for wall mounting Cable Gland Optional or Blanking Plug Not Shown DO NOT apply caulking or sealant on or around the MGS 250 or its base Figure 6 Front and Back Views of MGS 250 Base 6490 9000 Revision 3 21 MGS 250 Manual Section 3 Wiring and Configuration 3 1 Overview Prior to wiring and configuring the MGS 250 assure the following conditions have been met e MGS 250 backplate is mounted in an appropriate location e the cover panel is removed If the cover panel was reattached after mounting open the gas detector enclosure by pressing the top latch with a suitable screwdriver or other flat blade With the top latch depressed pull the housing apart by grasping the sides and pulling straight out Align and press together to close Z4VAC 24vDC OUT L N GND GND OT an aa al Terminal Block Terminal Block Positions 1 6 Positions 7 12 Cable Gland Optional or Blanking Plug Cable Gland Not Shown Installed Figure 7 Terminal Blocks and Cable Glands gland right have a 14 cable capacity each NOTE Install the optional cable gland on the right side of the base unit if needed
15. 1 2 34 5 6 7 8 9 10 1112 JAVAC 24vDC OUT RS4BS RELAY B A SH NC C NO COM Figure 11 Sample Relay Output Wiring energized By default the relay is set to be normally de d NOTE The relay can be programed to be failsafe normally energized This can be set using parameter P 06 Make relay connections NO NG or both using 18 to 20 AWG wires to terminal block positions 10 11 and 12 see Figure 11 noting normally open normally closed and common connectors per Table 7 Table 7 Relay Output Terminal Block Connections Function x Pin Wiring Termination Relay NC contact k Relay common contact Relay NO contact 26 6490 9000 Revision 3 MGS 250 Manual 3 5 Modbus Network Configuration If your application includes a Modbus network make network connections RS 485 A and RS 485 B using 18 to 24 AWG shielded twisted pair wires with 120 ohm characteristic impedance to terminal block positions 7 and 8 see Figure 12 noting inverted B and non inverted A signal connectors per Table 8 1 2 34 56 7 8 910 1112 24VAC 24VDC OUT R5485 RELAY L N GND GND B A SH NC C NO Shield RS 485 A Non inverted RS 485 B Inverted Figure 12 Modbus Network Wiring Table 8 Modbus Network Communications Connections Function i Wiring Termination RS 485 B inverted Modbus Network C ae RS 485 A non inverted ommunications RS 485 shield use only 18 24 AWG
16. 4 334 5000 Toll Free 1 800 736 4666 Fax 724 334 5001 Murco Ltd A Bacharach Company Bacharach of Canada 114a George s Street Lower 20 Amber Street Unit 7 Dun Laoghaire Markham Ontario L3R 5P4 Co Dublin Ireland Canada Phone 353 1 284 6388 Phone 905 470 8985 Fax 353 1 284 6389 Fax 905 470 8963
17. 4VDC 23 3 3 Wiring Alarm Output Analog Signal 25 3 4 Wiring the Digital Alarm Output Relay 26 3 5 Modbus Network Configuration 27 3 6 CONCUSSION av 29 SECTION 4 OPERATION AND STABILIZATION 30 41 Power Up nd Warm Deae EE Ge NE ER ge ie GR eee 30 272 SPANN PS 30 23 PeromaManiZero vr 30 12 Aae 31 25 635 DEPOT FUN oats Pee ees 31 25 h OVET VIEW NT 31 45 2 INON CCa EaultS ee a GE ek tau teamed 31 A 3 Cleaver 32 SECTION 5 CONFIGURE THE GAS DETECTOR 33 5 1 BEE NE NNN ee 33 6490 9000 Revision 3 5 MGS 250 Manual 52 SNE PINE 34 5 1 NEMND 34 5 2 2 Configuration Parameters L a u u ie ee ee 34 s3 Ge pe se us ES um unumanmi amia EE EE 42 SECTION 6 FUNCTIONAL TESTS AND ADJUSTMENTS 43 PN PE GE OR tO EE EE NE ee GE TE ESTE AE 43 6 2 Bump Testing vs Adjusting Detector Response 44 6 3 BUMP FET 45 6 4 Adjustment Using Calibration Gas 46 SECTION 7 MODBUS COMMUNICATIONS 49 71 IAtOAWEHOR re 49 7 20 COMMUNICATIONS SANS 49 7 3
18. CONFIGURATIONN 22 Figure 7 Terminal Blocks and Cable Glands 22 Figure 8 Supply Power Wiring Options 23 Figure 9 Maintaining Neutral Polarity 24 Figure 10 Analog Output Wiring 25 Figure 11 Sample Relay Output Wiring 26 Figure 12 Modbus Network Wiring 27 Figure 13 Setting Network Termination Resistors 29 SECTION 5 CONFIGURE THE GAS DETECTOR 33 Figure 14 The User Interface of the MGS 250 33 Figure 15 Analog Output Scaling Options 39 SECTION 6 FUNCTIONAL TESTS AND ADJUSTMENTS 43 Figure 16 Using Call Oration Gass u uy un Re usa SG 46 6490 9000 Revision 3 7 MGS 250 Manual List of Tables SECTION 1 INTRODUCTION 9 Table 1 Broadband Gas Groups and Performance P N 6401 0500 10 Table 2 Gas Specific Detector Measurement Pe
19. CTION 8 TROUBLESHOOTING 53 Table 18 Fault Codes ss u ua u T kaa 54 Table 19 Diagiiostie ATtrIDUtes u uu u u u l L GE eg ee pu De ere ie 55 Table 20 Other Symptoms and Possible Causes 57 SECTION 9 REPLACEMENT PARTS AND ACCESSORIES 58 Table 21 Replacement Parts and Accessories 58 8 6490 9000 Revision 3 MGS 250 Manual Section 1 Introduction 1 1 Overview The MGS 250 NDIR non dispersive infrared is a state of the art fixed gas detector which can detect a wide range of refrigerant gases The MGS 250 can be used on a stand alone basis or integrated into controls or a Building Management System BMS The MGS 250 can be used in locations that require continuous monitoring and to add gas detection solutions to an existing system Power LED 4 digit LED Display Enclosure Information Button Up Button Down Button Enter Select Button Cable Glands 2 Places Test Gas Port Figure 1 MGS 250 Components 6490 9000 Revision 3 9 MGS 250 Manual 1 2 Detection Options 1 2 1 Broadband vs Gas Specific The MGS 250 NDIR refrigerant gas detectors are available in two versions broadband and gas specific 1 2 2 Broadband Gas Detection The broadband gas detector P N 6401 0500 is used as a general purpose
20. ION OF THIS UNIT THESE NOTES ARE ONLY INTENDED AS A GUIDE AND THE MANUFACTURER BEARS NO RESPONSIBILITY FOR THE INSTALLATION OR OPERATION OF THIS UNIT FAILURE TO INSTALL AND OPERATE THE UNIT IN ACCORDANCE WITH THESE INSTRUCTIONS AND WITH INDUSTRY GUIDELINES MAY CAUSE SERIOUS INJURY INCLUDING DEATH AND THE MANUFACTURER WILL NOT BE HELD RESPONSIBLE IN THIS REGARD 6490 9000 Revision 3 3 MGS 250 Manual 4 6490 9000 Revision 3 MGS 250 Manual Table of Contents SECTION Ls INTRODUCTION sii asses eas ede d os e ee ese dee ee SO Ge Soe ee Ge ES Ge dees 9 ENVER 9 12 DETECTION OPNE ua DE asus 10 1 21 Broadband vs Gas Speci C ristaro na 10 1 2 2 Broadband Gas Detection ccccccsssccccsseccceeeccssseccsenseesaaesessaaees 10 1 23 Detecting Specific Gases uuu GE ee ee Ge GE 11 1 3 Remote Contreller OPTIONS Ese Ser Se ge Re Ge se ge Ne Vd GN ER 15 1 4 Parts LISE SEEN u u GN Ge GE RR N OE ER EG GE ee ua 15 I De Species 16 SECTION 2 MOUNTING THE GAS DETECTOR 17 2 1 Warnings and PrerequiSites arenon na A E 17 22 WIOUNTINE LOCatiou uuu uuu EE u DE EG We GE n a 17 2 2 1 General Placement Guidelines 17 222 MacNee ROOTS 18 2 2 3 Referated Sea 18 71 Ur 19 23 Moununs Procedure saa 19 SECTION 3 WIRING AND CONFIGURATION 22 SL ENN Se 22 3 2 Wiring Supply Power 24VAC or 2
21. NTAINS SERVICE FACILITIES AT LOCATIONS WORLDWIDE SOME DISTRIBUTORS AGENTS MAY ALSO HAVE REPAIR FACILITIES HOWEVER BACHARACH ASSUMES NO LIABILITY FOR SERVICE PERFORMED BY ANYONE OTHER THAN BACHARACH PERSONNEL REPAIRS ARE WARRANTED FOR 90 DAYS AFTER DATE OF SHIPMENT SENSORS PUMPS FILTERS AND BATTERIES HAVE INDIVIDUAL WARRANTIES SHOULD YOUR GAS DETECTOR REQUIRE NON WARRANTY REPAIR YOU MAY CONTACT THE DISTRIBUTOR FROM WHOM IT WAS PURCHASED OR YOU MAY CONTACT BACHARACH DIRECTLY IF BACHARACH IS TO DO THE REPAIR WORK SEND THE GAS DETECTOR PREPAID TO THE APPROPRIATE ADDRESS BELOW Contact Information Shipping Address www mybacharach com rmaform Bacharach Inc United Phone 724 334 5000 621 Hunt Valley Circle States Toll Free 1 800 736 4666 New Kensington PA 15068 USA Fax 724 334 5001 ATTN Service Department Murco Ltd A Bacharach Company Ireland 353 1 284 6388 114A Georges Street Lower 353 1 284 6389 Dun Laoghaire Dublin Ireland ATTN Service Department Bacharach of Canada 905 470 8985 20 Amber Street Unit 7 Canada 905 470 8963 Markham Ontario L8R 5P4 Canada support BachCan ca ATTN Service Department 2 6490 9000 Revision 3 MGS 250 Manual ALWAYS INCLUDE YOUR RMA ff ADDRESS TELEPHONE NUMBER CONTACT NAME SHIPPING BILLING INFORMATION AND A DESCRIPTION OF THE DEFECT AS YOU PERCEIVE IT YOU WILL BE CONTACTED WITH A COST ESTIMATE FOR EXPECTED REPAIRS PRIOR TO THE PERFORMANCE OF ANY SERVICE WORK FO
22. R LIABILITY REASONS BACHARACH HAS A POLICY OF PERFORMING ALL NEEDED REPAIRS TO RESTORE THE GAS DETECTOR TO FULL OPERATING CONDITION PRIOR TO SHIPPING EQUIPMENT TO BACHARACH CONTACT THE APPROPRIATE OFFICE FOR AN RMA RETURN MERCHANDISE AUTHORIZATION ALL RETURNED GOODS MUST BE ACCOMPANIED BY AN RMA NUMBER PACK THE EQUIPMENT WELL IN ITS ORIGINAL PACKING IF POSSIBLE AS BACHARACH CANNOT BE HELD RESPONSIBLE FOR ANY DAMAGE INCURRED DURING SHIPPING TO OUR FACILITY NOTICES COPYRIGHTS THIS MANUAL IS SUBJECT TO COPYRIGHT PROTECTION ALL RIGHTS ARE RESERVED UNDER INTERNATIONAL AND DOMESTIC COPYRIGHT LAWS THIS MANUAL MAY NOT BE COPIED OR TRANSLATED IN WHOLE OR IN PART IN ANY MANNER OR FORMAT WITHOUT THE WRITTEN PERMISSION OF BACHARACH INC ALL SOFTWARE WHICH BACHARACH UTILIZES AND OR DISTRIBUTES HOLDS A PROPRIETARY INTEREST AND IS ALSO SUBJECT TO COPYRIGHT PROTECTION AND ALL RIGHTS ARE RESERVED NO PARTY MAY USE OR COPY SUCH SOFTWARE IN ANY MANNER OR FORMAT EXCEPT TO THE EXTENT THAT BACHARACH GRANTS THEM A LICENSE TO DO SO IF THIS SOFTWARE IS BEING LOADED ONTO MORE THAN ONE COMPUTER EXTRA SOFTWARE LICENSES MUST BE PURCHASED TECHNICIAN USE ONLY THIS UNIT MUST BE INSTALLED BY A QUALIFIED TECHNICIAN WHO WILL INSTALL THIS UNIT IN ACCORDANCE WITH THESE INSTRUCTIONS AND THE STANDARDS IN THEIR PARTICULAR INDUSTRY COUNTRY OPERATORS OF THE UNIT SHOULD BE AWARE OF THE REGULATIONS AND STANDARDS IN THEIR INDUSTRY COUNTRY FOR THE OPERAT
23. S 250 exits setup mode automatically 42 6490 9000 Revision 3 MGS 250 Manual Section 6 Functional Tests and Adjustments 6 1 Introduction To comply with the requirements of EN378 and the European F GAS regulation gas detectors must be tested annually However local regulations may specify the nature and frequency of this test CAUTION Check local regulations on calibration or testing requirements components that can be easily damaged Neither touch nor disturb any of these components IMPORTANT Bacharach recommends annual checks and adjustment using calibration gas Calibration gas adjustment frequency may be extended based on application but should never exceed 2 years CAUTION The MGS 250 contains sensitive electronic CAUTION In applications where life safety is critical calibration gas adjustment should be done quarterly every 3 months or on a more frequent basis Bacharach is not responsible for setting safety practices and policies Safe work procedures including calibration policies are best determined by company policy industry standards and local codes gt CAUTION Failure to test or adjust the unit in accordance with applicable instructions and with industry guidelines may N result in serious injury or death The manufacturer is not liable for any loss injury or damage arising from improper testing incorrect adjustment or inappropriate use of the unit MGS 250 must have been powered up and
24. al information 6490 9000 Revision 3 53 MGS 250 Manual Table 18 Fault Codes Description Fault Code Gas Detector Temperature Fault Gas Detector Temperature Rate of Change Fault Hex l Code Possible Causes 0x0001 Gas Detector temperature reports gt 55 C or lt 35 C 0x0002 Temperature rate of change exceeds 1 C min for more than 15 minutes RS485 RX 0x0004 Message too long for Fault receive buffer RS485 CRC Fault Open Loop Fault Modbus Fault PPM Over range Fault Input Voltage Fault 54 Transmission is corrupted computed CRC doesn t match transmitted CRC Possible wiring connection and or termination issue exists When analog output type is 4 20ma and loop is open use 18 24AWG shielded twisted pair with 120 ohm characteristic impedance for Modbus connections Modbus message was truncated or timed out early PPM exceeds 9999 This may indicate a very large gross leak If no leak is present it indicates a gas detector error Input supply power to the MGS 250 is out of range i e 24V 20 IMPORTANT If this fault is active the gas detector is offline and not monitoring Correct the input supply voltage to restore normal operation 6490 9000 Revision 3 MGS 250 Manual ae Hex Description Fault Code Code Possible Causes Critical Faults Critical fault Cycle power to the sensor and see of the fault clears If not the gas detector should b
25. allowed to d IMPORTANT Before testing the gas detectors on site the stabilize 6490 9000 Revision 3 43 MGS 250 Manual IMPORTANT After initial installation the MGS 250 should be gas tested to ensure proper operation IMPORTANT The testing and or adjustment of the unit must be carried out by a suitably qualified technician and must be done e in accordance with this manual e in compliance with locally applicable guidelines and regulations Qualified operators of the unit should be aware of the regulations and standards set down by the industry country for the testing or calibration of this unit This manual is only intended as a guide and insofar as permitted by law the manufacturer accepts no responsibility for the calibration testing or operation of this unit The frequency and nature of testing or calibration may be determined by local regulation or standards EN378 and the F GAS Regulation require an annual check in accordance with the manufacturer s recommendation 6 2 Bump Testing vs Adjusting Detector Response There are two concepts that need to be differentiated e bump test e gas detector response adjustment A bump test exposes the gas detector to a gas The operator then observes the gas detector s response to the gas The objectives are two fold e establishes if the gas detector is reacting to the gas e determines if all of the detector outputs are working correctly There are two types of bump
26. conditions that will cause gas detector issues Table 20 Other Symptoms and Possible Causes Symptom Possible Cause s Green power LED Check power supply Check wiring off Alarms in the If you experience alarms in the absence of a leak try absence of a leak setting an alarm delay Perform a bump test to ensure proper operation 6490 9000 Revision 3 57 MGS 250 Manual Section 9 Replacement Parts and Accessories The following items are available as replacement parts NOTE All modules come ready to mount to the original mounting base provided Table 21 Replacement Parts and Accessories Part Number Description 0051 2320 6400 0014 5400 0015 6400 0016 6400 0017 6400 0018 6400 0019 6400 0020 6400 0021 6400 0022 6400 0023 6400 0024 6400 0025 6400 0026 6400 0027 Gas Detector Module R507 Calibrated 6400 0028 6400 0029 6400 0030 6490 9000 Installation and Operation Manual 6900 0001 Splash Shield Kit Accessory Provides additional protection for wash down or impact Includes mounting hardware for attaching to walls NOTE The gas detector response time will lengthen when the splash shield is used The installer is responsible for determining whether the response time is suitable for the application 1 Replacement gas detector modules do not include the mounting base order P N 6400 0014 58 6490 9000 Revision 3 MGS 250 Manual C DECLARATION OF CONFORMITY The manufacturer
27. display never shuts off all operating modes When ON the display shows the current gas concentration or 0 if below the squelch Note that P 09 is disabled if P 19 0 00 OFF during normal operation when the ppm value is below the alarm setpoint default 01 ON In either case the display will blink the measured PPM value during an alarm state D _ ff RS485 Node Address 1 8 Sets the RS 485 node address 0001 to 0255 Gas Groups Specific Gas Selection Selects either gas group number for broadband operation or specific gas name for gas specific mode Broadband Select from 3 groups of gases 1 R134a R404a R407a R407c R407f R427a R507 HFO1233ZD 2 R422a R422d HFO1234YF and HFO1234Ze 3 R22 by itself Specific Gas The actual refrigerant name is shown Select the appropriate refrigerant NOTE Gas specific detectors are factory calibrated to a single refrigerant using specialized manufacturing equipment If another refrigerant is selected which differs from the factory calibrated setting the built in calibration no longer applies Further improvement in detector accuracy may be gained by applying calibration gas containing the newly selected refrigerant and adjusting the gas detector reading to match see Parameter P 17 36 6490 9000 Revision 3 MGS 250 Manual Parameter Description Buzzer Mute Time Sets a time 0 59 minutes during which the active buzzer remains muted e after the
28. e removed from service and r Ta replaced 8 2 Diagnostics Attributes P 18 Use this option to review the built in diagnostic attributes Access the parameter list see Section 5 and select P 18 Press the Enter button to access the diagnostics and then use the UP or DOWN button to select each attribute The following information is available Table 19 Diagnostic Attributes Attribute Description Displays the current fault condition code in hex format 0000 no faults are active XXXX HEX number See Table 18 for the HEX format cross reference Displays a hex format code that corresponds to any faults that occurred since the internal fault record was last erased See Table 18 for the HEX format cross reference The records may be erased by pressing the ENTER button Displays the number of days that the MGS 250 has been in service The value of this attribute rolls over after 9999 Displays the elapsed time in days from the last gas adjustment or test This value is automatically reset to 0000 after completing a gas adjustment via Test Mode P 17 Note that the new adjustment is stored using the Enter button The value may be reset to 0000 by pressing the ENTER button 6490 9000 Revision 3 55 MGS 250 Manual Attribute Description Reserved Ra Displays the sensor temperature in C Displays the sensors approximate rate of temperature change per half minute interval C change over 30 second
29. e aa amp ANS EF FR tt Z NEUTRAL 24 VAC NEUTRAL TRANSFORMER Figure 9 Maintaining Neutral Polarity 24 6490 9000 Revision 3 MGS 250 Manual 3 3 Wiring Alarm Output Analog Signal The MGS 250 provides an analog output signal that is proportional to the level of gas detected to configure the analog output This is done electronically d NOTE No jumpers or hardware switch settings are reduired from the front panel display Connect two 18 to 20 AWG wires to terminal block positions 5 and 6 see Figure 10 noting ground and signal polarity per Table 6 1 2 34 56 7 8 9 10 1112 2AVAC 24VDC OUT RS485 RELAY L N GND GND Analog Output Signal Analog Output Ground Figure 10 Analog Output Wiring Table 6 Alarm Output Terminal Block Connections Function x Pin Wiring Termination Analog Analog output ground Output 6 Analog output signal The type of output signal on pins 5 and 6 is programmable using the analog output type parameter P 03 Refer to Section 5 for details 6490 9000 Revision 3 25 MGS 250 Manual 3 4 Wiring the Digital Alarm Output Relay An alarm setpoint may be programmed from the front panel of the MGS 250 When the the sensed gas level exceeds the alarm setpoint the MGS 250 enters the alarm state An on board relay is tied to the alarm state so you may activate or deactivate external equipment based on the MGS 250 s current alarm status
30. e unit will automatically go offline for a ten minute period after the parameter list is exited This allows time for the test gas to clear before the unit becomes active If no activity occurs for ten minutes the unit exits the gas test mode 40 6490 9000 Revision 3 MGS 250 Manual Parameter x Description D did Diagnostics Menu i Tm Parameter 18 provides access to the self diagnostic information The LED display shows DIAG until the Enter button is pressed Use the UP and DOWN buttons to scroll through the list of diagnostic attributes A 01 Current fault condition A 02 Last fault A 03 Days in service A 04 Days since last adjust test A 05 A 07 Factory Use Only A 08 Detector temperature in C A 09 Temperature rate of change A 10 A 17 Factory Use Only To aid in troubleshooting the operator may choose to reset the gas detector to its default state by holding both the UP and DOWN buttons for 5 seconds while in the Diagnostics Menu All settings including the alarm setpoint gas adjustments the selected gas curve calibration data the Modbus address etc revert to specific default values after a reset IMPORTANT Calibrations on either gas specific or broadband models are lost after a reset This returns the gas detector to an uncalibrated condition See parameter P 17 for information on how to recalibrate the gas detector See Section 8 for a complete list of codes and details on
31. gross leak detector and is factory tested and certified It is shipped from the factory with accuracy as shown in Table 1 gas dependent If more accurate detection is needed gas specific versions are available which are factory certified and calibrated to the target refrigerant The broadband gas detector combines refrigerants into three groups shown in Figure 2 Measurement performance is based on an average response profile for all of the gases within the group calibration gas and the adjustment procedure detailed in d NOTE Greater accuracy may be achieved through the use of Section 6 Table 1 Broadband Gas Groups and Performance P N 6401 0500 Group x Value for Param 11 Refrigerant As Shipped Accuracy R123 R134a R404a R407a R4070 1 See Section 5 for information on Parameter 11 and other configuration instructions 10 6490 9000 Revision 3 MGS 250 Manual MGS 250 Broadband Version 6401 0500 x Co NS Ko gro Weg aye core Configured for up gt Group 2 R134a R404a R407a R407c R407f R410a R427a R507 HFO1233ZD R422d HFO1234YF HFO1234Ze ri N m TE O o a S O O O t i a O D OD un wi ZE rg rg je O OD DO D D c m ro mg OD 2 2 D D E Mo g is O O O i i i CO cn co Figure 2 Broadband Gas Groups 1 3 1 2 3 Detecting Specific Gases Each gas specific gas detector PNs 6401 0501 to 6401 0515 is shipped factory calibra
32. hen environmental conditions exist that are outside the product s specified operating range or if an installation error has occurred wrong wiring for example The gas detector will typically continue to monitor its surroundings except for fault F 08 and may report inaccurate readings and false alarms Correcting non critical faults is a matter of waiting for the environmental conditions to return to a more typical condition correcting wiring mistakes or in some cases relocating the gas detector For example placing the gas detector near a forced air heater may cause temperature faults The non critical fault range is F 01 to F 08 Critical faults indicate a functional problem that results in the gas detector no longer monitoring its surroundings for refrigerant The fault number is displayed and the power LED is turned off indicating that the gas detector is offline The critical fault range is F 09 to F 16 If any of these faults occur first try to clear the faults by cycling power to the sensor The easiest way to do this is by removing the sensor from the base and reattaching If the fault returns after cycling power the gas detector should be removed from service and replaced Additionally the faults are stored as a hex number and can be accessed in the Diagnostics menu P 18 The associated hex codes are listed next to the Fault Code in Table 18 Refer to Diagnostics Menu P 18 in the next section for addition
33. ight the LED display With a bump test you can see the functions of the gas detector e the LED display will light and show the detected PPM concentration once the alarm setpoint is reached e the relay and audible alarm will function as configured including any delays set ON or OFF e the output 0 10V for example will show the gas level Ideally bump tests are conducted on site in a clean air atmosphere 6490 9000 Revision 3 45 MGS 250 Manual Bump Testing Using Calibration Gas Cylinders Remove the Splash Shield accessory if one is used Connect the regulator to the test gas port using 3 mm or 1 8 inside diameter tubing see below Expose the gas detector to gas from the cylinder Monitor the LED display reading Refer to the specifications section for acceptance criteria 1 0 l min Calibration Gas Figure 16 Using Calibration Gas 6 4 Adjustment Using Calibration Gas Adjustment Using Calibration Gas requires a gas cylinder with the appropriate gas and concentration Note that Bacharach offers a calibration kit that consists of a calibration gas cylinder and a flow regulation valve with flexible non absorbent tubing 46 6490 9000 Revision 3 MGS 250 Manual NOTE For improved accuracy and response the gas detector should be protected from excess drafts while d performing the adjustment Excess air circulation may dilute the applied calibration gas and lead to lower than expected respon
34. larms The following occurs during an alarm condition Table 9 MGS 250 Behavior during Alarm Conditions Item Behavior During Alarm State Green LED On solid Display On blinks reports detected PPM concentration Audible Alarm On if enabled and after programmed delay expires Relay Output Activates after any programmed delay expires Analog Output Changes proportionally with gas concentration as configured Modbus Registers Registers indicate the alarm condition ppm concentration etc NOTE The alarm feature includes a 20 dead band to d prevent alarm chatter if the concentration hovers near the alarm setpoint Once the alarm has been triggered it will remain latched until the concentration drops below 80 of the alarm setpoint 4 5 Gas Detector Faults 4 5 1 Overview There are two levels of fault monitoring built into the gas detector e Non critical e Critical 4 5 2 Non Critical Faults Non critical faults typically recover by allowing the gas detector surroundings to stabilize for example after a defrost cycle The gas detector continues to monitor its surroundings during non critical faults but may report inaccurate readings The following occurs when a non critical fault condition exists 6490 9000 Revision 3 31 MGS 250 Manual Table 10 MGS 250 Behavior during a Non Critical Fault Item Behavior During Non Critical Fault State Green LED On solid Display Shows the appropriate fault code
35. lat blade With the top latch depressed pull the housing apart by grasping the sides and pulling straight out With the housing separated the mounting base with terminal blocks will be visible See Figure 5 IMPORTANT Do not apply caulking or other material around the gas detector base The gas detector relies on air d exchange through the spaces between the base and the gas detector housing Do not obstruct the small gap around the housing and the base with any material Step x Mounting Procedure el Open the housing see Figure 5 Position the base to the pre determined acceptable mounting location Use the gas detector base to mark the mounting locations as needed The hole pattern on the back plate is sized to mount the gas detector onto various electrical junction boxes The other holes may be used as needed to mount the gas detector to other structures or onto a wall 6490 9000 Revision 3 19 MGS 250 Manual Mounting Procedure Wall Mount Junction Box Mount Attach the MGS 250 base to Attach the MGS 250 base to the mounting surface using the junction box using two 6 screws provided mounting hardware provided through two of the mounting with your junction box holes being careful not to through the two junction box over tighten the screws holes Refer to Figure 6 for Refer to Figure 6 for the the locations of the two locations of mounting holes on junction box mounting holes the base on the base 4 Unless
36. lso consider ease of access for maintenance The size and nature of the site will help to decide which method is the most appropriate to use Locations requiring the most protection in a machinery or plant room would be around compressors pressurized storage vessels refrigerant cylinders or storage rooms or pipelines The most common leak sources are valves gauges flanges joints brazed or mechanical filling or draining connections etc e In machinery rooms where there is little or no airflow placement options are o Point Detection where gas detectors are located as near as possible to the most likely sources of leakage such as the compressor expansion valves mechanical joints or cable duct trenches o Perimeter Detection where gas detectors completely surround the area or equipment e Halocarbon and hydrocarbon refrigerants are heavier than air gases and as such the gas detectors should be located near ground level 6 to 18 inches from the floor NOTE Gas detectors should be positioned just far enough back from any high pressure parts to allow gas clouds to form and be detected Otherwise a gas leak might pass by in a high speed jet and not be detected by the gas detector d e Make sure that pits stairwells and trenches are monitored since they may fill with stagnant pockets of gas e For racks or chillers pre fitted with refrigerant gas detectors these should be mounted so as to monitor the compressors e Do not mou
37. munications Settings There are 255 selections available to be set electronically from addresses 1 to 255 inclusive Modbus data with a zero in the address field is received by all detectors regardless of the address selected to enable the master device to broadcast simultaneously to all the detectors Refer to the specifications section page 16 for information on RS 485 network communications parameters such as data bits stop bits etc 6490 9000 Revision 3 49 MGS 250 Manual 7 3 Analog Input Registers Analog input registers are read only and use function code 04 Table 14 Analog Input Registers Reg x Description x Range x Units x P 1000 Concentration gas level 0 100 1001 Concentration gas level 0 65 535 ppm ppm O Pm 1004 Alarm set point full scale 0 100 C i L EE je me 1010 Le 1011 me s 1012 16 bit fault code 0 65535 50 6490 9000 Revision 3 MGS 250 Manual 7 4 Analog Output Registers Analog output registers are readable using function code 03 and writable using function code 06 Table 15 Analog Output Registers Reg Description Range x Units x P 2000 Alarm setpoint 75 3500 Alarm ON delay Alarm flag _ EO register 3000 is set to 1 2003 Alarm OFF delay 2008 Analog output type P 02 ppm min min min 0 9600 2009 Baud rate 1 19200 1to3 broadband Gas curve number unit or gas none P 11 type gas specific 2012 Analog ou
38. n an atmosphere that is known not to d contain any background concentrations of refrigerant Bacharach offers portable gas detectors for this purpose Contact the factory for more information 4 3 Perform a Manual Zero After the gas detector stabilizes the power LED stops flashing and is lit continuously Bacharach recommends manually zeroing the MGS 250 after a 1 hour stabilization period Increase this stabilization period to 3 hours for freezer applications To manually zero the gas detector press and hold the UP and DOWN buttons simultaneously for 5 seconds The gas detector will beep and the display will show zEro when zeroing is complete The display will show fAiL if the temperature is changing too quickly or there is an active alarm condition Additionally certain system faults F 08 F 10 through 14 and or F 16 will prevent a manual zero from being performed NOTE Manual zero should be performed in the environment of operation and at the typical operating temperature NOTE Subsequent manual zeroes may be performed provided the atmosphere around the gas detector is free of all background concentrations of refrigerant Clean air or d nitrogen applied to the calibration port for five minutes may be used to ensure the gas detector is clear of all background gas Re zeroing with background refrigerant present will cause the gas detector to report incorrect readings 30 6490 9000 Revision 3 MGS 250 Manual 4 4 A
39. nt the gas detector directly to pipes or structures that are subject to strong vibration 2 2 3 Refrigerated Spaces In refrigerated spaces gas detectors should be located away from doors in the return airflow to the evaporators on a sidewall below head high is preferred or on the ceiling not directly in front of an evaporator nor in 18 6490 9000 Revision 3 MGS 250 Manual any direct airflow In large rooms with multiple evaporators gas detectors should be mounted on the central line between 2 adjacent evaporators as turbulence will result in airflows mixing 2 2 4 Chillers In the case of small water or air cooled enclosed chiller units mount the gas detector so as to monitor airflow to the extract fans With larger models also place a gas detector inside the enclosure under or adjacent to the compressors For enclosed air cooled chillers or the outdoor unit for variable refrigerant volume and variable refrigerant flow VRV VRF systems mount the gas detector so as to monitor airflow to the extract fan With large units also place a gas detector inside the enclosure under or adjacent to the compressors 2 3 Mounting Procedure To open the housing as received use a flat blade screwdriver and depress the top latch While pushing the latch grasp the back edge of the housing near the latch and pull the back away When mounted the housing is simply opened by pressing the top latch with a suitable screwdriver or other f
40. or may be changed to respond to any of the other listed refrigerants see parameter P 11 in section 5 2 If changed the gas detector will have a lower accuracy for the target refrigerant without calibration In this example that accuracy is 16 of reading i R134A CALIBRATION GAS 5 of reading 9 gt gt 5 u D O O lt CT 0 Q 69 O c 5 G D co o x By applying calibration gas containing the new target refrigerant and via the routine described in Section 6 4 the gas detector may then be adjusted to respond with the calibrated accuracy of 5 of reading as shown in Table 2 for the new target refrigerant Optional Recalibration For Improved Accuracy Figure 4 Changing Gas Types and Accuracy 14 6490 9000 Revision 3 MGS 250 Manual 1 3 Remote Controller Options The MGS can connect to any controller through the standard analog output voltage and current see Table 4 for options the standard alarm relay or the digital Modbus RTU communications interface 1 4 Parts List Table 3 shows a list of components that are shipped with your order Table 3 Parts List Part Number x Description 6401 0515 MGS 250 HFO1233ZD 6490 9000 Installation and Operation Manual Various Depends on Model Ordered 6490 9000 Revision 3 15 MGS 250 Manual 1 5 Specifications Table 4 Technical Specifications Specification Description 24 VAC 5 VA min 50 60 Hz 2 5 W max 4 20 mA 0 5 V
41. r parameter displayed V When pressed together and held for 5 seconds this T key combination manually zeroes the gas detector Saves the currently displayed parameter to memory 6490 9000 Revision 3 33 MGS 250 Manual 5 2 Setting Parameters 5 2 1 Overview Press and hold the information button for 5 seconds then release to activate the parameter list Each parameter is shown in turn by using the UP or DOWN buttons The parameter is shown as P XX with XX being the parameter value Pressing Enter while a parameter is displayed allows the attributes of the parameter to be set Each Parameter has its own attributes as shown in the following table Set the attributes as desired and then press Enter to save the setting 5 2 2 Configuration Parameters Table 13 Parameter Numbers Names and Descriptions Parameter Description Maintenance Mode Sets gas detector to offline mode for 30 minutes 00 Gas detector is online with normal response to its surroundings default 01 Gas detector is offline and suppresses all outputs Display reads oFFL offline during 30 minute timeout Alarm Setpoint sets desired PPM value range 75 to 3500 ppm above which alarm occurs Use UP or DOWN buttons For faster coarse adjustment hold either button to sweep through the adjustment range quickly Default setpoint is 200 ppm Analog Output Type Selects output type 00 Selects 0 5 V 01 Selects 1 5 V default
42. rformance 13 Table 3 Parts Le 15 Table 4 Technical peelliea ONS is ie ee 16 SECTION 3 WIRING AND CONFIGURATIONN 22 Table 5 Power Options and Terminal Block Connections 23 Table 6 Alarm Output Terminal Block Connections 25 Table 7 Relay Output Terminal Block Connections 26 Table 8 Modbus Network Communications Connections 27 SECTION 4 OPERATION AND STABILIZATION 30 Table 9 MGS 250 Behavior during Alarm Conditions 31 Table 10 MGS 250 Behavior during a Non Critical Fault 32 Table 11 MGS 250 Behavior during a Critical Fault 32 SECTION 5 CONFIGURE THE GAS DETECTQOR 33 Table 12 Button Functions ua u a a eee 33 Table 13 Parameter Numbers Names and Descriptions 34 SECTION 7 MODBUS COMMUNICATIONS 49 Table 14 Analog INDUE RESISCENS vane 50 Table 15 Analog Output Registers 51 Table 16 Input Status Far aars 52 Table 17 Output Sta CUS Fla SS uyu u u ee wasasapa maaa E 52 SE
43. s 8 3 Resetting MGS 250 to Default Values The gas detector may be reset to its default state if needed to aid in troubleshooting All settings including alarm setpoint gas adjustments selected gas curve calibration data Modbus address etc revert to specific default values after a reset The broadband sensor option P N 6401 0500 resets to gas group 1 Gas specific products P Ns 6401 0501 through 6401 0515 are reset to the R134a gas curve IMPORTANT Calibrations on either gas specific or broadband models are lost after a reset This returns the gas detector to an uncalibrated condition See parameter P 17 for information on how to recalibrate the gas detector Before performing this operation it is advisable to write down all the parameter settings so they can be re programmed 56 6490 9000 Revision 3 MGS 250 Manual Step x Description Access diagnostics menu P 18 Press and hold both the UP and DOWN buttons for 5 seconds This will cause the following to occur e Allthe LED segments will then light for 3 seconds e The gas detector resets to the default settings e The gas detector beeper sounds for 3 seconds 3 After 3 seconds the user is returned to the parameter list at parameter P 18 4 The gas detector may now be re programmed for further troubleshooting if needed 8 4 Other Symptoms Other common wiring problems can also cause the gas detector to malfunction Check below for additional
44. s NOTE The mounting location of the monitor should allow it to be easily accessible for visual monitoring and servicing NOTE The monitor must be connected to a marked suitably located and easily reached switch or circuit breaker as means of disconnection NOTE Connect monitor power and signaling terminals using wiring that complies with local electrical codes or regulations for the intended application CAUTION Do NOT mount the MGS 250 directly to vibrating machinery as the vibrations may degrade the gas detector s performance gt amp amp gt 2 2 Mounting Locations 2 2 1 General Placement Guidelines NOTE The MGS 250 should be installed plumb and level and securely fastened to a rigid mounting surface water spray the optional splash guard P N 6900 0001 d NOTE When installed in areas that may be subjected to should be used in conjunction with the MGS 250 Gas detectors must be located within the appropriate wire lengths from the central control unit if used 6490 9000 Revision 3 17 MGS 250 Manual 2 2 2 Machinery Rooms There is no absolute rule in determining the number of gas detectors and their locations However a number of simple guidelines will help to make a decision Gas detectors monitor a point as opposed to an area If the gas leak does not reach the detector then no alarm will be triggered Therefore it is extremely important to carefully select the gas detector location A
45. se Adjustment Using Calibration Gas Cylinders Connect the regulator to the test gas port using 3 mm or 1 8 inside diameter tubing Enable parameter P 17 Gas Test Mode see Section 5 When enabled the display continuously cycles through the following e CAL is displayed briefly e Next the gas group number or gas type based on product code is displayed e Then four dashes are displayed After gas is applied and the 75 PPM squelch level is exceeded the live concentration replaces the four dashes NOTE The analog outputs relay activity and RS 485 ppm reporting are suspended in Gas Test Mode to prevent false alarms 1 3 Expose the gas detector to gas from the cylinder Monitor the 4 digit LED display reading Wait for the ppm reading to stabilize This should take approximately 4 6 minutes Minor changes less than 5 ppm in 10 seconds are considered stable readings Compare the response value with the calibration gas concentration Adjust the gas detector displayed value by using the UP or DOWN buttons to increase or decrease the value shown Adjust until the reading is within 2 of the calibration gas For example if the calibration gas is 1000 ppm the gas detector is adjusted properly when the displayed reading is between 980 and 1020 ppm Press the Enter button to store the new adjustment Turn off the calibration gas and remove the tubing from the calibration port 6490 9000 Revision 3 47
46. shielded twisted pair wire with 120 ohm d IMPORTANT For Modbus network communications wiring characteristic impedance 6490 9000 Revision 3 27 MGS 250 Manual IMPORTANT Connect the RS 485 cable shield to pin 9 board ground NOTE Selection of the Modbus Address and Baud Rate is completed through the gas detector setup menu described d later No jumpers or hardware switch settings are required to configure the Modbus communications network This is done electronically from the front panel display NOTE For Modbus communications with the MGS 250 the default communications parameters are as follows e Baud rate 9 600 e Parity no parity e Stop bits 1 Confirm that all devices on the Modbus communications network including a Building Management System are configured similarly If the MGS 250 is at the end of the RS 485 network then be sure to set the RS 485 terminator on the printed circuit board PCB to IN This applies a terminating resistor to the end of the wires per the requirements of the RS 485 protocol The terminator should be set to OUT for all other installation conditions the device at each end of the network see Figure 13 This d IMPORTANT Be sure to enable the termination resistor on includes the Building Management System if used NOTE Care should be exercised when changing the terminator switch Before powering the gas detector use a fine pointed device or paper clip to slide the switch
47. ted to its specific target refrigerant Refer to Figure 3 and Table 2 6490 9000 Revision 3 11 MGS 250 Manual R22 rO R404a R407a P N 6401 0501 P N 6401 0502 P N 6401 0503 P N 6401 0504 P N 6401 0505 P N 6401 0506 P N 6401 0507 P N 6401 0508 P N 6401 0509 P N 6401 0510 P N 6401 0511 P N 6401 0512 P N 6401 0513 P N 6401 0514 P N 6401 0515 Figure 3 Gas Specific MGS 250 Gas Detectors 6490 9000 Revision 3 MGS 250 Manual Table 2 Gas Specific Detector Measurement Performance Part Number Refrigerant Accuracy 6401 0501 R22 5 6401 0502 5 6401 0503 5 6401 0504 5 6401 0505 3 6401 0506 3 6401 0507 3 6401 0508 3 6401 0509 5 6401 0510 5 6401 0511 3 6401 0512 5 6401 0513 5 6401 0514 5 6401 0515 1 See Section 5 for information on Parameter 11 and other configuration instructions NOTE Gas specific detectors can be re calibrated in the field to new target gases Use optional calibration instructions in d Chapter 6 for increased accuracy when detecting a new target gas that is different from the as shipped target gas Refer to the example in Figure 4 6490 9000 Revision 3 13 MGS 250 Manual 5 of reading Part number 6401 0501 R22 is factory calibrated to R22 and has an as shipped R22 response accuracy of 5 of reading P 11 P 11 22 1398 e DY R134A 16 of reading As Shipped The gas detect
48. tput full scale ppm 100 3500 opm P 16 R O 6490 9000 Revision 3 51 none P 13 I 53 O O 53 D D MGS 250 Manual 7 5 Input Status Flags Input Status Flags are readable using function code 02 Table 16 Input Status Flags Reg x Description 3000 Alarm flag 0 or 1 Alarm 3001 Relay state 0 or 1 energized 3002 Detector fault 0 or 1 fault 3003 Red LED state 0 or 1 ON 3004 s LED state 0 or 1 powered Start up 0 normal operation 0 1 warming up MEE 7 6 Output Status Flags Output Status Flags are readable using function code 01 and writable using function code 05 Table 17 Output Status Flags Reg x Description x Range x P 4000 Buzzer flag 0 or 1 ON oa me 4001 Test required If operating for 0 Okay gt 1 year 1 requires testing 1 Test 52 6490 9000 Revision 3 MGS 250 Manual Section 8 Troubleshooting 8 1 Fault Codes To comply with the requirements of EN378 and the European F GAS regulation gas detectors must be tested annually However local regulations may specify the nature and frequency of this test The MGS 250 features sophisticated internal status monitoring and will indicate whether a fault condition exists both on the front display F XX with XX being the fault number and over the Modbus communications network There are two classes of fault conditions critical and non critical In general non critical faults occur W
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