The C-22G-5B is a Belimo communication module for the 22G gas monitor system. It aggregates data from CAN bus–networked gas monitors and provides centralized control and BMS connectivity. This variant provides two SPDT relays plus BACnet MS/TP for dual-stage ventilation sequencing and BMS reporting. All 22G communication modules wire via a daisy chain, support standalone operation and networking of up to 32 devices, and carry a 5-year warranty.
Pairs with any Belimo 22G gas monitor on the CAN bus, and is especially useful with the CAN-bus-only monitors that rely on a downstream module for relay, analog, or BACnet output: 22G02-5C, 22G14-5C, 22G0214-5C, 22G15-5C6, 22G21-5C. Full 22G monitor range: 22G02-5A, 22G02-5B, 22G02-5C, 22G14-5A, 22G14-5B, 22G14-5C, 22G0214-5A, 22G0214-5B, 22G0214-5C, 22G15-5A3, 22G15-5A5, 22G15-5B3, 22G15-5B5, 22G15-5B6, 22G15-5C6, 22G21-5C.
Centralized control of multi-monitor installations — parking structures, mechanical rooms, and refrigeration plants where alarm relays, analog trending, or BACnet reporting are consolidated at one location rather than wired at each monitor.
Key Features
Two SPDT relays support two-stage ventilation control (e.g. low-speed and high-speed fan banks), with BACnet MS/TP for native BMS integration.
Aggregates data from up to 32 daisy-chained 22G monitors on a single CAN bus segment.
Backlit LCD shows gas type, live concentration, and alarm-level status.
Technical Specifications
| Specification | Detail |
|---|---|
| Type | Communication Module |
| Number of Relays | 2 |
| Number of Analog Outputs | 0 |
| Communication | CAN bus + BACnet MS/TP |
| Relay Output | SPDT, 5 A @ 125 VAC, non-inductive |
| Nominal Voltage | AC 24 V, 50/60 Hz |
| Power Consumption | AC 5 VA |
| Cable Entry | 2 top, 2 bottom, 1 rear — 1/2" EMT |
| Cable Specification | Power: 18-20 AWG; Comm: 22-24 AWG twisted pair, shielded |
| Fuse | Thermal PTC, auto-reset |
| Max Network Devices | Up to 32 on CAN bus daisy chain |
| Display | LCD with backlight — gas type, concentration, alarm level |
| Max Altitude | 6,562 ft (2,000 m) |
| Enclosure Rating | NEMA 2 / IEC IP44 |
| Housing Material | UL94 5VA |
| Manufacturer | Belimo |
| Manufacturer Part Number | C-22G-5B |
| Warranty | 5-year factory warranty |
Documentation
Frequently Asked Questions
What does a communication module do?
It collects gas concentration and alarm data from 22G monitors over the CAN bus and centralizes the outputs — relays for fan/damper control, analog signals for BAS trending, and/or BACnet MS/TP for BMS integration — at one location instead of at each monitor.
Which monitors is the C-22G-5B compatible with?
Any Belimo 22G gas monitor networked on the CAN bus. It is most valuable alongside the CAN-bus-only "-5C" monitors (e.g. 22G02-5C, 22G14-5C, 22G0214-5C), which depend on a module like this for relay, analog, or BACnet output.
How are modules and monitors wired together?
All 22G devices daisy-chain on a single CAN bus segment — up to 32 devices — using 22-24 AWG twisted-pair shielded cable. Termination resistors are required at the bus endpoints.
- Accessory Type:
- Communication Module
- Number of Relays:
- 2
- Number of Analog Outputs:
- 0
- Communication:
- CAN bus + BACnet MS/TP
- Compatible With:
- Belimo 22G Gas Monitors
