Bacharach MGS-550 Industrial Gas Detector


Bacharach’s MGS-550 leak detector combines electrochemical, semiconductor, catalytic bead and infrared sensors into one platform to support leak detection for the new low GWP (Global Warming Potential) refrigerant blends as well as natural refrigerants to enable gas leak detection in the often harsh environments of industrial refrigeration.The MGS-550 can easily be integrated into any building management system (BMS). The ModbuRss RTU interface allows the user to program and configure the unit remotely through the BMS. Remote access gives complete control to the user when using Modbus. Alternatively, electrical current or volt analog output provides an industry standard reading using 4-20mA.

Bacharach MGS-550 Industrial Gas Detector

Having three integrated relays within each instrument reduces the need for having to wire alarm devices back to a central control system. Because of the integrated relays, the Bacharach MGS-550 can be operated as a stand-alone system. Each relay can be individually programmed to trigger alarm devices and actions separately or as a redundant system. The straightforward menu structure is identical regardless of the type of sensors used, reducing the costs and amount of time for training required upon installation or during maintenance. Bacharach’s MGS-550 offers the flexibility of adding a second sensor at any point in time without the need for any additional controllers. Any sensor can be remotely mounted from the main instrument to a distance of 5 meters or 15 feet. It meets the requirements of EN 378 and ASHRAE 15.

One or two sensor capabilityDetects two gases and/or in two locations with one instrument
Remote sensor capabilitiesFlexible placement in hard to reach areas
Analog and digital interfaceEase of integration with multiple control devices
On-board relaysConnects to local alarm devices for saving costs on installation
Magnetic wandNon-intrusive configuration and calibration
Status indicator and LED displayProvides at-a-glance status overview and comprehensive direct user interface
Optional MGS-408 ControllerCreate an independent, centralised alarm system with up to 6 gas detectors


Gases and RangeRefrigerants1,000 / 10,000 ppm
 CO25,000 / 10,000 / 20,000 / 30,000 / 40,000 / 50,000 ppm
 NH3*100** / 1,000** / 5,000** / 10,000 ppm / 100% LEL
 CO**500 / 1,000 ppm
 Combustible Gases5,000 ppm / 100% LEL
 C2H42,000 ppm
 NO2***20 ppm
Repeatability ±5% of applied gas concentration
Display Red 5-digit, 7-segmented LED and green status LEDs
OutputAnalog4 to 20 mA, 0 to 5 V, 0 to 10 V, 1 to 5 V, 2 to 10 V
 DigitalModbus RTU via RS 485
Power 19.5 to 28.5 VDC or 24 VAC ±20%; 3- or 4-wire
Relay Three relays, SPDT, user assignable
  Rating 2 A @ 30 VDC NO, 0.5 A @ 125 VDC, 0.25 A @ 250 VAC, 30 W, resistive load
EnclosureGeneral purposeABS IP66 with four M20 × 1.5 cable glands
Size (W×H×D) ApproxGeneral purpose8.3” x 8.9” x 3.4” / 210 × 225 × 85 mm
Weight Approx GP: 2 lbs / 1 kg; XP: 3.5 lbs / 1.6 kg
Approvals CE, UL / CSA / IEC EN 61010-1
Ambient ConditionsTemperatureSemiconductor-40 to 122°F / -40 to +50°C
  Electrochemical-5 to 122°F / -20 to + 50°C*
  Infrared-40 to 122°F / -40 to +50°C
  Catalytic Bead-40 to 122°F / -40 to +50°C
 Humidity5 to 90 % RH, non condensing
 Pressure23.6 to 32.5 inch Hg / 800 to 1,100 mbar

* NH3 available as low temperature version -40°F / 40°C (not for 5,000 ppm Electrochemical sensor)
** IP66 rated; not available in XP enclosure
*** Not IP66 rated; not available in XP enclosure


GasSensor RangeTypeBase Unit, 1 Local SensorLocal Sensor
Butane0-100 %LELIR6600-80166600-8816
Butane0-100 %LELCB6600-80396600-8839
CO0-500 ppmEC6600-80806600-8880
CO20-5,000 ppmIR6600-80106600-8810
CO20-10,000 ppmIR6600-80116600-8811
CO20-20,000 ppmIR6600-80126600-8812
CO20-30,000 ppmIR6600-80136600-8813
CO20-40,000 ppmIR6600-80146600-8814
CO20-50,000 ppmIR6600-80156600-8815
Ethylene0-2,000 ppmSC6600-80756600-8875
HFO1234YF0-1,000 ppmSC6600-80526600-8852
HFO1234ZE0-1,000 ppmSC6600-80536600-8853
HFO1234ZE0-10,000 ppmSC6600-80676600-8867
LPG0-100 %LELCB6600-80356600-8835
Methane0-100 %LELIR6600-80176600-8817
Methane0-100 %LELCB6600-80366600-8836
Methane0-5,000 ppmSC6600-80736600-8873
NH30-10,000 ppmSC6600-80696600-8869
NH30-100 %LELCB6600-80346600-8834
NH30-100 ppmEC6600-80196600-8819
NH30-1,000 ppmEC6600-80206600-8820
NH30-5,000 ppmEC6600-80216600-8821
NO20-20 ppmEC6600-80246600-8824
O20-30 Vol%EC6600-80256600-8825
Propane0-100 %LELIR6600-80186600-8818
Propane0-100 %LELCB6600-80386600-8838
R-134a0-1,000 ppmSC6600-80426600-8842
R-134a0-10,000 ppmSC6600-80566600-8856
R-2900-5,000 ppmSC6600-80706600-8870
R-320-1,000 ppmSC6600-80416600-8841
R-320-10,000 ppmSC6600-80556600-8855
R-404A0-1,000 ppmSC6600-80436600-8843
R-404A0-10,000 ppmSC6600-80576600-8857
R-407A0-1,000 ppmSC6600-80446600-8844
R-407A0-10,000 ppmSC6600-80586600-8858
R-407C0-1,000 ppmSC6600-80456600-8845
R-407C0-10,000 ppmSC6600-80596600-8859
R-407F0-1,000 ppmSC6600-80466600-8846
R-407F0-10,000 ppmSC6600-80606600-8860
R-410A0-1,000 ppmSC6600-80476600-8847
R-410A0-10,000 ppmSC6600-80616600-8861
R-422A0-1,000 ppmSC6600-80486600-8848
R-422A0-10,000 ppmSC6600-80626600-8862
R-422D0-1,000 ppmSC6600-80496600-8849
R-422D0-10,000 ppmSC6600-80636600-8863
R-427A0-1,000 ppmSC6600-80506600-8850
R-448A0-1,000 ppmSC6600-80766600-8876
R-449A0-1,000 ppmSC6600-80776600-8877
R-452A0-1,000 ppmSC6600-80786600-8878
R-5070-1,000 ppmSC6600-80516600-8851
R-5070-10,000 ppmSC6600-80656600-8865
R-513A0-1,000 ppmSC6600-80796600-8879
R-6000-5,000 ppmSC6600-80716600-8871