Honeywell RM7896C1010 7800 Series Relay Module
The Honeywell RM7896C1010 serves as the primary RM7896C Relay Module utilized to execute flame safeguard sequencing and valve actuation timing across 7800 Series burner control platforms.
Hardware Specifications
| Parameter | Specification |
|---|---|
| Model | RM7896C1010 |
| Brand | Honeywell |
| Origin | USA |
| Weight | 3.00 lbs |
| Dimensions | 5.0 in x 5.0 in x 2.5 in |
| Operating Temp | -40 deg C to 60 deg C |
| Power Consumption | 10 W maximum |
| Supply Voltage | 120 VAC (+10/-15%), 50/60 Hz |
| Pilot Ignition Type | Interrupted pilot type |
| Valve Control Timing | Delayed main valve actuation |
| Post Purge Duration | 15 sec post purge |
| Main Flame Establishing Period | 10 sec |
| Pilot Flame Establishing Period | 4 sec or 10 sec selectable |
| System Interlocks | Selectable interlock configurations |
Cold Junction Compensation and Loop Protocol Performance
Designed to integrate with high-precision process loops, the relay module maintains galvanic channel-to-channel isolation across flame detection circuits and safety interlocks. Built-in cold junction compensation (CJC) stability ensures precise signal conversion across extreme temperature variations, eliminating drift in ambient sensing logic. High-speed optical isolation barriers prevent transient voltage spikes and ground loops along the 4-20 mA HART feedback path from reaching the microprocessor, enabling uninterrupted burner sequencing during complex process disturbances.
Frequently Asked Questions
Q: How does the delayed main valve feature function during startup sequencing?
A: The module holds the main fuel valve circuit open until the pilot flame is established during the 4-second or 10-second pilot flame establishing period (PFEP), preventing raw fuel accumulation in the combustion chamber.
Q: What power input is required to operate the RM7896C1010 relay module?
A: The module requires a line-voltage power supply rated at 120 VAC (+10/-15%) at a line frequency of 50/60 Hz.
Q: What occurs during the 15-second post purge phase following flame shutdown?
A: The control unit keeps the combustion air blower energized for exactly 15 seconds after fuel valve closure to clear unburned fuel gases from the furnace pass.
Field Installation Guidelines
Mount the module to its mating wiring subbase inside an IP54 or NEMA-rated enclosure. Maintain a minimum separation of 100 mm between line-voltage ignition transformer wiring and low-voltage sensor cables to suppress electromagnetic noise. Ensure the earth grounding terminal connects directly to the panel backplate using a low-impedance copper conductor. Verify that all terminal block screws are torqued down securely before applying 120 VAC power to prevent high-resistance contact points.
Honeywell RM7896C1010 7800 Series Relay Module
Honeywell RM7896C1010 7800 Series Relay Module
The Honeywell RM7896C1010 serves as the primary RM7896C Relay Module utilized to execute flame safeguard sequencing and valve actuation timing across 7800 Series burner control platforms.
Hardware Specifications
| Parameter | Specification |
|---|---|
| Model | RM7896C1010 |
| Brand | Honeywell |
| Origin | USA |
| Weight | 3.00 lbs |
| Dimensions | 5.0 in x 5.0 in x 2.5 in |
| Operating Temp | -40 deg C to 60 deg C |
| Power Consumption | 10 W maximum |
| Supply Voltage | 120 VAC (+10/-15%), 50/60 Hz |
| Pilot Ignition Type | Interrupted pilot type |
| Valve Control Timing | Delayed main valve actuation |
| Post Purge Duration | 15 sec post purge |
| Main Flame Establishing Period | 10 sec |
| Pilot Flame Establishing Period | 4 sec or 10 sec selectable |
| System Interlocks | Selectable interlock configurations |
Cold Junction Compensation and Loop Protocol Performance
Designed to integrate with high-precision process loops, the relay module maintains galvanic channel-to-channel isolation across flame detection circuits and safety interlocks. Built-in cold junction compensation (CJC) stability ensures precise signal conversion across extreme temperature variations, eliminating drift in ambient sensing logic. High-speed optical isolation barriers prevent transient voltage spikes and ground loops along the 4-20 mA HART feedback path from reaching the microprocessor, enabling uninterrupted burner sequencing during complex process disturbances.
Frequently Asked Questions
Q: How does the delayed main valve feature function during startup sequencing?
A: The module holds the main fuel valve circuit open until the pilot flame is established during the 4-second or 10-second pilot flame establishing period (PFEP), preventing raw fuel accumulation in the combustion chamber.
Q: What power input is required to operate the RM7896C1010 relay module?
A: The module requires a line-voltage power supply rated at 120 VAC (+10/-15%) at a line frequency of 50/60 Hz.
Q: What occurs during the 15-second post purge phase following flame shutdown?
A: The control unit keeps the combustion air blower energized for exactly 15 seconds after fuel valve closure to clear unburned fuel gases from the furnace pass.
Field Installation Guidelines
Mount the module to its mating wiring subbase inside an IP54 or NEMA-rated enclosure. Maintain a minimum separation of 100 mm between line-voltage ignition transformer wiring and low-voltage sensor cables to suppress electromagnetic noise. Ensure the earth grounding terminal connects directly to the panel backplate using a low-impedance copper conductor. Verify that all terminal block screws are torqued down securely before applying 120 VAC power to prevent high-resistance contact points.
