Honeywell RM7800M1011 Relay Module

The Honeywell RM7800M1011 , also cataloged as the RM7800M1011 Relay Module, operates as a dedicated hardware component for automatic burner sequencing, flame supervision, and safe firing rate execution within Honeywell 7800 Series burner control systems.

Hardware Specifications

4-20 mA HART Loop Protocol & Channel Isolation

The module manages automatic burner programming sequences, low-fire proven purge checks, and interrupted/intermittent pilot timing using an internal microprocessor. System status is indicated via five front-panel LEDs and the included S7800 Keyboard Display Module. Integrated flame supervision circuitry interfaces with interchangeable plug-in flame amplifiers (R7847, R7848, R7849, R7851, R7852, R7861, or R7886) to execute dynamic self-checks and force a fail-safe safety shutdown upon flame failure or loss of running interlocks. Non-volatile memory preserves lockout history, sequence position, and diagnostic fault logs across main power loss events.

Frequently Asked Questions

Q: Which plug-in accessories are mandatory for the operation of the RM7800M1011 module?

A: The module requires a Q7800A or Q7800B universal wiring subbase, an ST7800A plug-in purge timer card to define pre-purge duration, and an R78 Series flame signal amplifier tailored to the optical or ionization flame sensor in use.

Q: How is the low-fire proven purge state verified during the burner startup sequence?

A: Onboard sequence logic monitors the low-fire switch interlock circuit during the pre-purge cycle; if the low-fire position is not proven prior to ignition trial, the controller holds the sequence and prevents pilot valve energization.

Field Installation Guidelines

1. Isolate and disconnect all 120 VAC line power from the subbase prior to installing, removing, or wiring the RM7800M1011 relay module.
2. Securely mount the Q7800 subbase to the panel and verify that subbase ground terminals are bonded directly to cabinet chassis earth.
3. Route flame scanner lead wires in isolated grounded conduit, strictly separated from high-voltage ignition transformer cabling to prevent high-frequency noise coupling.
4. Insert the required ST7800A purge timer card and R78 series flame amplifier into the module before seating the unit onto the Q7800 subbase and tightening mounting screws.