Honeywell RM7898A1000 7800 Series Relay Module
Configured for microprocessor-based burner management and flame safety sequencing in 7800 Series control systems, the Honeywell RM7898A1000 (RM7898A Relay Module) provides direct physical/electrical execution. It controls automatic burner sequencing, ignition timing, flame supervision, and safe shutdown operations across industrial combustion systems.
Hardware Specifications
| Parameter | Specification |
|---|---|
| Model | RM7898A1000 (RM7898A) |
| Brand | Honeywell |
| Origin | USA |
| Weight | 1.04 kg (2.30 lbs) |
| Dimensions | 127 mm x 127 mm x 60 mm |
| Operating Temp | -40 to 60 deg C |
| Power Consumption | 120 VAC (+10/-15%), 50/60 Hz (10 VA max) |
| Module Type | Primary Burner Control Relay Module |
| Features | Selectable Pilot Type, Preignition Purge |
| Timing Functions | 4 s or 10 s Pilot Flame Establishing Period (PFEP) |
| Interlocks | Selectable Running Interlocks |
| System Family | 7800 Series Burner Controls |
4-20 mA HART Loop Protocol Integration and Channel-to-Channel Isolation
The RM7898A1000 incorporates optically decoupled inputs and decoupled internal signal lines to isolate sensitive microprocessors from high-voltage ignition noise and field contact surges. Channel-to-channel isolation between low-voltage flame sensing circuits and 120 VAC output terminals prevents electrical transients from interfering with logic execution. When operated in combined control cabinets alongside process instrumentation using 4-20 mA HART loop protocol transmitters or cold junction compensation (CJC) thermocouple modules, the relay module maintains high electromagnetic noise immunity and prevents signal degradation across field control loops.
Frequently Asked Questions
Q: What is the key functional difference between the RM7898A1000 and the RM7898A1018?
A: The RM7898A1000 provides standard 7800 Series burner sequencing and flame monitoring without the integrated Valve Proving System (VPS) present on the RM7898A1018 model.
Q: Is the RM7898A1000 compatible with standard Q7800 wiring subbases?
A: Yes. The card mounts directly onto standard 7800 Series subbases (such as the Q7800A, B, or C), engaging the rear terminal pins into the subbase chassis sockets.
Field Installation Guidelines
- Disconnect all 120 VAC electrical power feeds to the control cabinet before mounting or wiring the relay module.
- Align the rear connector header pins of the RM7898A1000 with the terminal block socket of the Q7800 subbase.
- Push the module firmly onto the subbase until the top and bottom captive retaining screws line up with the mounting posts.
- Torque the retaining screws to 0.8 Nm to secure the unit against vibration and ensure electrical contact continuity.
- Route flame sensor input cables in dedicated shielded conduit separate from high-voltage AC lines, grounding the shield at the panel functional earth (FE) terminal.
Honeywell RM7898A1000 7800 Series Relay Module
Honeywell RM7898A1000 7800 Series Relay Module
Configured for microprocessor-based burner management and flame safety sequencing in 7800 Series control systems, the Honeywell RM7898A1000 (RM7898A Relay Module) provides direct physical/electrical execution. It controls automatic burner sequencing, ignition timing, flame supervision, and safe shutdown operations across industrial combustion systems.
Hardware Specifications
| Parameter | Specification |
|---|---|
| Model | RM7898A1000 (RM7898A) |
| Brand | Honeywell |
| Origin | USA |
| Weight | 1.04 kg (2.30 lbs) |
| Dimensions | 127 mm x 127 mm x 60 mm |
| Operating Temp | -40 to 60 deg C |
| Power Consumption | 120 VAC (+10/-15%), 50/60 Hz (10 VA max) |
| Module Type | Primary Burner Control Relay Module |
| Features | Selectable Pilot Type, Preignition Purge |
| Timing Functions | 4 s or 10 s Pilot Flame Establishing Period (PFEP) |
| Interlocks | Selectable Running Interlocks |
| System Family | 7800 Series Burner Controls |
4-20 mA HART Loop Protocol Integration and Channel-to-Channel Isolation
The RM7898A1000 incorporates optically decoupled inputs and decoupled internal signal lines to isolate sensitive microprocessors from high-voltage ignition noise and field contact surges. Channel-to-channel isolation between low-voltage flame sensing circuits and 120 VAC output terminals prevents electrical transients from interfering with logic execution. When operated in combined control cabinets alongside process instrumentation using 4-20 mA HART loop protocol transmitters or cold junction compensation (CJC) thermocouple modules, the relay module maintains high electromagnetic noise immunity and prevents signal degradation across field control loops.
Frequently Asked Questions
Q: What is the key functional difference between the RM7898A1000 and the RM7898A1018?
A: The RM7898A1000 provides standard 7800 Series burner sequencing and flame monitoring without the integrated Valve Proving System (VPS) present on the RM7898A1018 model.
Q: Is the RM7898A1000 compatible with standard Q7800 wiring subbases?
A: Yes. The card mounts directly onto standard 7800 Series subbases (such as the Q7800A, B, or C), engaging the rear terminal pins into the subbase chassis sockets.
Field Installation Guidelines
- Disconnect all 120 VAC electrical power feeds to the control cabinet before mounting or wiring the relay module.
- Align the rear connector header pins of the RM7898A1000 with the terminal block socket of the Q7800 subbase.
- Push the module firmly onto the subbase until the top and bottom captive retaining screws line up with the mounting posts.
- Torque the retaining screws to 0.8 Nm to secure the unit against vibration and ensure electrical contact continuity.
- Route flame sensor input cables in dedicated shielded conduit separate from high-voltage AC lines, grounding the shield at the panel functional earth (FE) terminal.
