MGS-401 Entrance Monitor

For Commercial & Industrial Applications - Entrance Monitor for Improving Safety

The MGS-401 Entrance Monitor provides improved safety for entrances to monitored areas such as mechanical rooms or walk-in freezers and coolers. The MGS-401 provides clear visual and audible alarms when in alert mode and can also display gas concentrations in the area that is being monitored helping with compliance of IIAR, ASHRAE 15, CSA B52, EN378

  • Perimeter strobe for “at-a-glance” system / alarm status
  • Seamless integration with all MSA Bacharach diffusion Gas Detectors
  • MGS-408 Controller powers up to (8) total of combination of MGS-401(s) and MGS Diffusion Gas Detectors
  • Modbus RTU Master / Slave provides seamless integration from connected gas detectors to many third-party BMS / BAS
  • Audible and visual alarms enable compliance with IIAR, ASHRAE 15, CSA B52 and EN378 – no additional hardware required
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The MSA Bacharach® MGS-401 Entrance Monitor centralizes the status of up to four (4) MSA Bacharach diffusion Gas Detectors, which in turn provides and audible and visual alarm outside a monitored space. In addition, the MGS-401 displays any gas concentration level in the space for additional information and visual monitoring. System configuration will determine whether the alarms signals are addressed in the monitored space or at a controller or BMS/BAS level.

Combining the MGS-401 Entrance Monitor with the MSA Bacharach MGS-408 Gas Controller and diffusion Gas Detectors provides a complete, single source gas detection system with an easy means of achieving compliance with refrigeration safety standards such as IIAR, ASHRAE 15, CSA B52 and EN376.


Example Configuration

MGS-401 Configuration Diagram


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Enclosure Rating: IP54
User Interface: Front Panel Push Button; DIP switches
Power: 24VAC/DC, +20%, 7W max.
Operating Voltage: Relay - 10A, 24VAC/DC
Relay Rating: RS485 Modbus RTU Client for Gas Detectors, RS485 Modbus RTU Server for BMS
Wiring: 2 × M20 / 1/2” Conduit (Power)
Alarm: Integrated high output visual strobe, Integrated high output audible alarm
Ambient Temperature: -4 to 122°F (-20 to 50°C)
Product Dimensions (L×W×H): 6.5 × 6.5 × 3.4" (165 × 165 × 87mm)
Product Weight: 1 lb, 11.07 oz (758 g)
Approvals: CE, UL / CSA / IEC EN 61010-1
Country of Origin: United States
Description Part Number
MGS-401 Entrance Monitor 6702-8030
Description Part Number
Sunshield for outdoor locations 6702-8030
Security Kit 1100-2534
Security Screws ((6) pcs. and driver bit) 1100-8950
>100dB External sounder (mounted in MGS-401 Cable Gland) 6900-0010