Description
8-relay expansion module that adds control outputs to QEL M-Controller gas detection systems
The QEL M-Relay module lets your M-Controller do more than just watch gas levels—it gives you extra “hands” in the field to actually switch equipment on and off. Each module adds up to eight DPDT relays that the M-Controller can use to start fans, open dampers, trigger horns and strobes, or interface with other control panels.
Controlled over an RS-485 communication link, the M-Relay can be mounted where it makes the most sense—near fans, starters, or other loads—so you don’t have to pull every wire all the way back to the main panel. It runs on 24 VAC/VDC and can be powered from the M-Controller’s port power or from a local supply, giving you flexibility in how you design and wire the job.
Each module has a simple DIP switch for addressing, so you can stack multiple M-Relay modules and let the M-Controller coordinate up to 99 total relays across a large garage, plant, or multi-zone facility.
Key Features & Benefits
Easy Relay Expansion for Bigger Jobs
Adds up to eight control relays per module, so your M-Controller can handle more fan stages, damper positions, purge zones, and alarm devices without adding a separate control system.
Flexible Placement with RS-485 Control
Uses an RS-485 communication link instead of individual relay wires back to the panel, so you can mount relay modules closer to the loads and cut down on conduit and homeruns.
Scales Up to 99 Relays System-Wide
The M-Controller’s three onboard relays are numbered 1–3; M-Relay modules pick up at relay 4 and can extend control all the way to relay 99, giving you plenty of capacity for large projects.
Simple Addressing and Setup
Each module is assigned an address from 0 to 11 using a four-position DIP switch on the circuit board. That makes it straightforward to label, document, and troubleshoot in the field.
Standard 24 VAC/VDC Power
Operates on 24 VAC or 24 VDC and can be powered either from the M-Controller’s port outputs or from a nearby power source, helping you match local power available in the panel or mechanical room.
Robust DPDT Relay Contacts
Uses DPDT (double-pole, double-throw) relays with contact ratings designed for typical control loads, so you can switch fan starters, interlocks, or interface points reliably as part of your gas detection system.
Key Specs
- Relays Per Module: Up to 8 DPDT relays
- System Capacity: Supports relay numbering from 4 to 99 when used with an M-Controller (3 onboard + up to 96 via M-Relay modules)
- Communication: RS-485 link between M-Controller and M-Relay
- Addressing: Module addresses 0–11 via 4-position DIP switch
- Supply Voltage: 24 VAC or 24 VDC
- Compatible Controller: QEL M-Controller Series Universal 40-Sensor Digital/Analog Controller
