RM7895A1014 Honeywell On-Off Primary Burner Control

The RM7895A,B,C,D are microprocessor-based integrated burner controls for automatically fired gas, oil, or combination fuel single burner applications. They are intended to replace the R4795 and R7795 Primary Controls. The RM7895A,B,C,D system consists of a relay module, subbase, amplifier, and purge card. 

Options include: 2-line VFD (see document 65- 0090-6) or 4-line LCD (see document 32-00110-01) Keyboard Display Module, Personal Computer Interface, Data ControlBus™ Module, remote display mounting, expanded annunciator and Combustion System Manager® Software. 

Functions provided by the RM7895A,B,C,D include automatic burner sequencing, flame supervision, system status indication, system or self-diagnostics and troubleshooting.

The Honeywell RM7895A1014 is part of the RM7895 series of On-Off Primary Burner Controls. These microprocessor-based integrated burner controls provide safety, functional capability, and features to efficiently manage single burner combustion in various applications, be it commercial or industrial.

Key features and details related to the RM7895A1014 and the broader RM7895 series include:

1. Microprocessor Technology: The use of microprocessor technology ensures accuracy, reliability, and enhanced functionality in controlling burner operations.

2. Safety: The RM7895 provides safety shutdown and monitoring for flame conditions. If a no-flame or unsafe condition is detected, the system ensures a quick shutdown to prevent unsafe operations.

3. Sequence Control: The system manages the startup and shutdown sequence of various burner components, such as the ignition, main burner firing, and other related functions, ensuring a smooth and safe operation.

4. Diagnostics: The RM7895 series typically comes with diagnostic LEDs which provide a clear indication of the operational status and potential fault conditions, simplifying troubleshooting and maintenance tasks.

5. Compatibility: These burner controls are designed to be compatible with a wide range of Honeywell flame detectors, flame amplifiers, and other related components.

6. Timing Functions: The RM7895 incorporates precise timing functions for ignition, trial for ignition periods, and other key operational sequences. This ensures that the burner operates within safe parameters.

7. Interlocks: These controls can accommodate various interlock inputs, allowing them to work in tandem with other safety devices and systems to provide a comprehensive safety solution.

8. Lockout and Reset: In the event of a flame failure or other detected fault conditions, the RM7895 will initiate a lockout, requiring manual or automatic reset (depending on the configuration and model). The control provides clear indications when a lockout condition has occurred.

9. Remote Reset Capability: Some models, including those in the RM7895 series, might offer remote reset functionality, allowing operators to reset the system remotely, adding a layer of convenience to operations.

10. Selectable Jumpers: Some models may have selectable jumpers to modify the default settings based on specific requirements.

For those looking to install, maintain, or troubleshoot the RM7895A1014 or similar models, it's crucial to refer to Honeywell's official technical documentation and manuals. These documents will provide comprehensive and up-to-date information on installation, specifications, safety precautions, and operational guidelines.

Here's the optimized description for the RM7895A1014:

Suggested Description

The Honeywell RM7895A1014 is a microprocessor-based on-off primary burner control with prepurge, designed for automatically fired gas, oil, or combination fuel single burner applications. It is the direct modern replacement for the legacy R4795 and R7795 Primary Controls, and the defining feature that sets it apart from the RM7890 series is its built-in prepurge capability — requiring an ST7800A Plug-in Purge Timer Card to be installed in the subbase alongside the standard amplifier.

As a full primary burner control, the RM7895A1014 handles automatic burner sequencing, prepurge timing, flame supervision, airflow interlock checking, safe-start checks, and safety lockout — making it the core controller of a flame safeguard system where a timed purge cycle is required before ignition.

Key Features

• On-off primary control with prepurge — the critical differentiator from the RM7890 series; a timed prepurge cycle runs before every ignition attempt
• Intermittent pilot — pilot established at startup and extinguished once main flame is proven
• Selectable pilot flame establishing period — 4-second or 10-second PFEP
• Intermittent main flame establishing period
• Recycles through prepurge on flame loss — if flame signal is lost during run, the control recycles through prepurge rather than going straight to lockout; failure to establish pilot results in lockout
• Safe-start check — prevents startup if a false flame signal is present
• Selectable airflow switch interlock — configurable via site jumper JR3 for applications with airflow proving requirements
• Built-in ignition crossover protection — guards against false flame signals in flame rod rectification systems
• Five status LEDs — real-time sequence indication for Power, Pilot, Flame, Main, and Alarm
• Interchangeable plug-in flame amplifiers — color-coded; supports rectification, UV, and IR detection
• Nonvolatile memory — retains history files and lockout status through power loss
• Optional remote reset capability
• Replaces R4795 and R7795 Primary Controls

Specifications

Required & Compatible Components

• Wiring Subbase: Q7800A2005/U Universal Wiring Subbase (required — note: 2000-series subbase required; 1000-series subbases are not compatible)
• Flame Signal Amplifier: R7847, R7848, R7849, R7851, R7852, R7861, or R7886 (required)
• Purge Timer Card: ST7800A Plug-in Purge Timer Card (required — this is an additional requirement vs. the RM7890 series)
• Display (optional): S7800A1142 4-line LCD or S7800A 2-line VFD Keyboard Display Module
• Optional add-ons: PC interface, Data ControlBus™ Module, remote display module, first-out expanded annunciator, Combustion System Manager™ software

Certifications & Approvals

• UL Listed — File No. MP268, Guide No. MCCZ
• Factory Mutual Approved — Report No. 1V9A0.AF
• Swiss Re (formerly IRI): Acceptable
• FCC Part 15, Class B Emissions

How the RM7895A1014 Differs from Related Models

Common Applications

The RM7895A1014 is used in commercial boilers, industrial process heaters, large furnaces, and combustion systems where applicable codes or equipment design require a timed prepurge cycle before ignition. It is the standard choice when replacing legacy R4795 or R7795 controls in existing systems, and is widely used in HVAC, steam, and hot water boiler applications where intermittent pilot operation with prepurge is specified.

Important Notes

• Subbase, amplifier, and purge card are all required — three components needed vs. two for the RM7890 series; the ST7800A purge timer card is often overlooked and must be ordered separately
• 2000-series subbase required — the Q7800A2005/U subbase is mandatory; older 1000-series subbases are not compatible with this relay module
• Keyboard Display Module is not included — order separately for programmable postpurge and fault history access
• Not weather-tight — must be protected by an approved enclosure when installed outdoors
• Condensing moisture can cause a safety shutdown — avoid environments where condensation may occur