background image

MGS Installation and Operation Manual 

 

 

1000-0085 Rev 0 

15 

2.6.  Air Conditioning (Direct Systems VRF/VRV) 

For compliance with EN378,  at least one detector shall be installed in each 

occupied  space being considered and the location of detectors shall be 

chosen in  relation to the refrigerant and they shall be located where the 

refrigerant from the leak will collect. In this case refrigerants are heavier than 

air and detectors  should have their sensors mounted low,  e.g.,  at less than 

bed height in the case of an hotel or other similar Category Class A spaces. 

Ceilings or other voids if not sealed are part of the occupied space. 

 

CAUTION:  

Monitoring ceiling voids in a hotel room would not 

strictly comply with EN378.

 

 

 

Do Mount In-Room Sensors… 

Don’t Mount Sensors… 

…at less than the normal heights of the 

occupants.  E.g., in a hotel room this is less 

than bed height (between 8 and 20 inches [200 

and 500 mm] off the floor). 

…under mirrors. 

…away from drafts and heat sources like 

radiators, etc. 

…at vanity units. 

… to avoid sources of steam. 

…in or near bathrooms. 

 

 

 

Summary of Contents for MGS

Page 1: ...MGS Gas Detector Installation and Operation Manual Instruction 1000 0085 Revision 0 July 2013 Product Leadership Training Service Reliability ...

Page 2: ...NS 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 AUTHORISED BY OBTAINING A RETURN MERCHANDISE AUTHORISATION RMA NUMBER CONTACT THE MANUFACTURER FOR A NUMBER AND PROCEDURES REQUIRED FOR ...

Page 3: ...IED OR TRANSLATED IN WHOLE OR IN PART IN ANY MANNER OR FORMAT WITHOUT THE WRITTEN PERMISSION OF MURCO ALL SOFTWARE USED AND OR DISTRIBUTED BY MURCO IS SUBJECT TO COPYRIGHT PROTECTION ALL RIGHTS ARE RESERVED NO PARTY MAY USE OR COPY SUCH SOFTWARE IN ANY MANNER OR FORMAT EXCEPT TO THE EXTENT THAT MURCO GRANTS THEM A LICENSE TO DO SO IF THIS SOFTWARE IS BEING LOADED ONTO MORE THAN ONE COMPUTER EXTRA ...

Page 4: ...Conditioning Direct Systems VRF VRV 15 Section 3 Housing Dimensions 16 Section 4 Operation and Stabilisation 20 Section 5 Configurations 21 5 1 Overview 21 5 2 Adjusting the Alarm Set Point 21 Section 6 Functional Tests and Calibration 22 6 1 Introduction 22 6 2 Bump Testing 24 6 3 Calibration Overview 27 6 4 Calculating Calibration Voltage 28 6 5 Calibrating Semiconductor SC Sensors 28 6 6 Calibr...

Page 5: ...ew buildings areas that require continuous monitoring with high tech gas sensor transmitters to add gas detection solutions to an existing system Typical detection applications include the detection of refrigerant gases combustible gases toxic gases and or volatile organic compounds The MGS Controller is an optional device used to remotely monitor up to six MGS devices For more information refer t...

Page 6: ...ensing Dimensions Weights per Enclosure Type see Note below Housing Dimensions Weight IP41 standard 86 x 142 x 53 mm 180 g IP66 optional 175 x 165 x 82 mm 629 g w Splash Guard 175 x 225 x 82 mm 700 g w Remote Sensor 175 x 155 x 82 mm 790 g w Exd Sensor Head 175 x 155 x 82 mm 1185 g w PRV Sensor Head 175 x 155 x 82 mm 830 g w Airflow Duct 175 x 125 x 82 mm 578 g Exd ATEX only 140 x 180 x 90 mm 2234...

Page 7: ...3800 3800 n a n a n a n a 4000 4000 n a n a n a n a 4400 4400 n a n a n a n a 4800 4800 n a n a n a n a 5000 5000 2500 n a n a n a 5400 5400 2700 n a n a n a 5800 5800 2900 2578 n a n a 6000 6000 3000 2667 n a n a 6400 6400 3200 2844 n a n a 6800 6800 3400 3022 n a n a 7000 7000 3500 3111 n a n a 7400 7400 3700 3289 n a n a 7800 7800 3900 3467 n a n a 8000 8000 4000 3556 n a 2548 8400 8400 4200 37...

Page 8: ...it to be easily accessible for visual monitoring and servicing NOTE The monitor must be connected by 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 NOTE This instrument can be equipped with a semicond...

Page 9: ...where such abnormalities may arise include the following Plant room maintenance activity involving solvent or paint fumes or refrigerant leaks Accidental gas migration in fruit ripening storage facilities bananas ethylene apples carbon dioxide Heavy localised exhaust fumes carbon monoxide dioxide propane from engine driven forklifts in confined spaces or close to sensors Murco recommends setting t...

Page 10: ...MGS Installation and Operation Manual 10 1000 0085 Rev 0 Figure 2 EC or IR Sensor Components and Wiring ...

Page 11: ...MGS Installation and Operation Manual 1000 0085 Rev 0 11 Figure 3 SC Sensor Components and Wiring ...

Page 12: ... Point P1 sets the trip point for the relay and audible alarm using the 0 5V scale measure at test points 0V and alarm test point TP1 Default factory setting is 50 of the range Time Delay A time delay for the operation of the relay and audible alarm can be selected using jumpers JP5 and JP6 Default factory setting is zero Audible Alarm The audible alarm can be disabled using jumper JP2 Default fac...

Page 13: ...ve the equipment to be monitored on a bracket or high on a wall within 12 in 300 mm of or on the ceiling provided there is no possibility of a thermal layer trapped under the ceiling preventing gas from reaching the sensor NOTE At very low temperatures e g refrigerated cold store ammonia gas becomes heavier than air With similar density or miscible gases e g CO or CO2 sensors should be mounted abo...

Page 14: ...variable refrigerant flow VRV VRF systems mount the sensor so as to monitor airflow to the extract fan With large units also place a sensor inside the enclosure under or adjacent to the compressors In the case of non enclosed outdoor units If there is an enclosed machinery section locate a sensor there In the case of units with enclosed compressors mount sensors in the enclosures Where you have pr...

Page 15: ...ctors should have their sensors mounted low e g at less than bed height in the case of an hotel or other similar Category Class A spaces Ceilings or other voids if not sealed are part of the occupied space CAUTION Monitoring ceiling voids in a hotel room would not strictly comply with EN378 Do Mount In Room Sensors Don t Mount Sensors at less than the normal heights of the occupants E g in a hotel...

Page 16: ...MGS Installation and Operation Manual 16 1000 0085 Rev 0 Section 3 Housing Dimensions Figure 4 MGS Standard Housing ...

Page 17: ...MGS Installation and Operation Manual 1000 0085 Rev 0 17 Figure 5 IP66 Housing with Splashguard ...

Page 18: ...MGS Installation and Operation Manual 18 1000 0085 Rev 0 Figure 6 IP66Airflow Duct Mount Housing Figure 7 Exd Housing Units mm ...

Page 19: ...l 1000 0085 Rev 0 19 For Dimensions and Mounting Locations See Figure 5 Figure 8 IP66 Housing with Remote Sensor Head NOTE For the Exd Remote Sensor Head and 16 4 ft 5 m cable the thread varies based on the model 9 8 feet 3 meters Typical ...

Page 20: ...V on the 1 5V output o 1 0V on the 2 10V output The typical time for various sensor types to stabilise is shown below Sensor Type Stabilisation Time Electrochemical EC 20 30 seconds Semiconductor SC 1 3 minutes Infrared IR 2 minutes On power up the electrochemical sensor outputs a signal voltage normally below the set alarm level Semiconductors output over the max scale i e 5V Both move towards ze...

Page 21: ...setting the jumpers Output Decide which output is required 4 20mA 1 5V 0 10V relay outputs etc See Figure 2 and Figure 3 for setting the jumpers 5 2 Adjusting the Alarm Set Point This process is the same for all versions using pot P1 and test points 0V and REF1 Step Adjusting the Alarm Relay 1 Locate Pot P1 and use it to adjust the set point at which the relay activates 2 Monitor the output betwee...

Page 22: ...ired due to differences in environmental conditions IMPORTANT If the MGS is exposed to a large leak it should be tested to ensure correct functionality by electrically resetting the zero setting and carrying out a bump test See procedures below IMPORTANT Murco recommends annual checks and gas calibration Murco also recommends sensor replacement every 3 years or as required Calibration frequency ma...

Page 23: ...in compliance with locally applicable guidelines and regulations Suitably 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...

Page 24: ... systems such as sprinkler systems plant shut down external sirens and beacons ventilation etc and disconnect as instructed by the customer Deactivate alarm delays if selected at JP5 JP6 as per Figure 2 and Figure 3 For bump test or calibration the MGS should be powered up for 24 hours The instrument should be fully stabilised per Section 4 6 2 Bump Testing After installation the units should be b...

Page 25: ...ANT After a semiconductor or electrochemical sensor is exposed to a substantial gas leak the sensor should be checked and replaced if necessary NOTE To test the audible alarm and or relay function check the delay is set at zero and expose to gas You can mute the audible alarm by removing jumper 3 Step Bump Testing Using Calibration Gas Cylinders 1 Remove the enclosure lid of the gas detector not i...

Page 26: ...ing Using Gas Ampoules 1 Make sure that both the ampoules and the calibration beaker are clean and dry 2 Unscrew the beaker hold screw and place the ampoule so that it sits in the base of the beaker see Figure 10 3 Tighten the wing nut screw onto the ampoule without breaking it 4 Remove the enclosure lid of the gas detector 5 Connect a voltmeter between pins 0V and VS to monitor sensor response in...

Page 27: ... 5 min 8 The voltage output will increase This confirms that the sensor is responding A response equivalent to at least 50 of the test gas typical will confirm that the system is in order if tested with the unit s specified span gas 9 Remove the beaker from the sensor Carefully remove any ampoule remains from the gas detector and beaker Figure 10 Gas Ampoules for Bump Testing 6 3 Calibration Overv...

Page 28: ...𝐬 𝐕𝐚𝐥𝐮𝐞 𝟓 𝐕 𝐒𝐞𝐧𝐬𝐨𝐫 𝐑𝐚𝐧𝐠𝐞 𝐕𝐨𝐥𝐭𝐚𝐠𝐞 𝟖𝟎𝟎 𝐩𝐩𝐦 𝟓 𝐕 𝟏𝟎𝟎𝟎 𝐩𝐩𝐦 𝟒 𝐕 So the output voltage signal should be adjusted to 4V 6 5 Calibrating Semiconductor SC Sensors Step Calibrating Semiconductor SC Sensors 1 Locate Pot P2 which is used to adjust the zero point 2 Monitor the output between 0V negative and VS positive 3 Adjust Pot P2 to 0 V or slightly positive 0 01 V is acceptable 4 Locate Pot P3 which is use...

Page 29: ...d VS positive 6 Expose the sensor to calibration gas and allow to stabilise approximately 6 minutes 7 Adjust pot VR202 to the voltage calculated in section 6 4 page 28 6 7 Calibrating Infrared IR Sensors Step Calibrating Infrared IR Sensors 1 Locate Pot VR203 which is used to adjust the zero point 2 Monitor the output between 0V negative and VS positive 3 Expose the sensor to pure 99 nitrogen unti...

Page 30: ...g another MGS to confirm the fault Red light on green led off indicates a fault Sensor may be disconnected from printed circuit board Check to see sensor is properly inserted into board The sensor has been damaged or has reached the end of life and needs to be exchanged Contact Murco for instructions and support Alarms in the absence of a leak Try setting an alarm delay Perform a bump test to ensu...

Page 31: ...d s and is in accordance with the following directive s Directive s 2004 108 EC EU EMC Directive 2006 95 EC Low Voltage Directive LVD Standard s IEC 61010 1 2010 EN 61010 1 2010 Safety Standards Electrical Equipment for Measurement Control and Laboratory Use Part 1 General Requirements EN 50270 2006 Electromagnetic Compatibility EMC Standards Electrical Apparatus for the Detection and Measurement ...

Page 32: ...MGS Installation and Operation Manual 32 1000 0085 Rev 0 MURCO 114A GEORGES STREET LOWER DUN LAOGHAIRE CO DUBLIN IRELAND Phone 353 1 284 6388 Fax 353 1 284 6389 www murcogasdetection com sales murco ie ...

Reviews: