Honeywell Original RM7840L1018 R7861A1026 RM7840L1075 R7849A1023 RM7800L1012 Combustion Controller EC/RM7800 Amplifier Card

I. Program Controllers (3 Models: Main Unit, Mounting Base, Plug-in Amplifier)

1. RM7840L1018

Core Features: Includes air pressure differential switch detection, intermittent ignition, and optional pre-purge functionality.

Functions: Fully automatic sequenced control (Pre-purge → Ignition → Low Fire → High Fire); Flame monitoring; Fault lockout; 5-way LED status indicators (Power / Pilot Flame / Main Flame / Run / Alarm); Non-volatile fault logging (retains records after power loss).

Timing Parameters: Pilot flame establishment time selectable (4s/10s); Main flame establishment time (10s/15s); Flame cutoff lead time (5s); Supports external air pressure interlock protection.

Compatibility: Pairs with R7849A/R7861A series amplifiers; Universal compatibility for UV (ultraviolet) and Ion Probe flame detection; Includes standard dust cover.

Applications: Gas boilers, natural gas burners, and applications requiring air pressure interlock protection.

2. RM7840L1075

RM7840L General Standard Edition: No air pressure detection; the flagship model of the 7840 series.

Functions: Identical to the RM7840L1018, but omits the air pressure switch wiring terminals; basic timing parameters are fixed. Can be fitted with an S7800A purge timer plug-in module to adjust pre-purge and post-purge durations.

Optional Accessories: External KDM remote display panel, remote reset terminal.

Dimensions: 127 × 127 mm; Net weight approx. 0.9 kg; Original manufacturer "Red Box" packaging.

Applications: Small to medium-sized gas/diesel burners, oven combustion systems.

3. RM7800L1012

The 7800 Series Flagship Model: Features an integrated S7800 keypad/display interface, Modbus communication support, and "First-Out" fault indication.

Exclusive Configuration: Integrated LCD control panel on the unit body allows for on-site modification of ignition timing and purge durations; Non-volatile memory retains a complete history of all faults; Supports remote communication monitoring and remote fault notification.

Detection Compatibility: Ion rectification, Ultraviolet (UV). Fully compatible with three types of flame detection signals—UV, IR, and rectification—with interchangeable, plug-in amplifier modules.

Timing: Pilot flame (4–10s, adjustable); Main flame (10–15s); Features intermittent, two-stage pilot valve control.

Applications: Large and medium-sized industrial boilers, thermal fluid heaters, and fully automated multi-stage combustion equipment.

II. Flame Signal Amplifiers (2 Models; plug into the side slot of the main controller; serve as flame signal processing modules)

1. R7861A1026 (Purple Label — UV Dynamic Self-Check Amplifier)

Compatible Probe: C7061 Series UV Flame Detectors (specifically for gas applications).

Key Feature: Dynamic, continuous self-checking—constantly monitoring the probe, wiring, and internal circuitry; immediately triggers a safety lockout on the controller in the event of a wiring break or probe failure.

Flame Failure Response Time (FFRT): Selectable 2s or 3s settings; Flame detection output: 0–5 VDC analog signal; includes a built-in test jack for on-site voltage measurement.

Positioning: Standard flame detection module for natural gas, LPG, and city gas combustion systems.

2. R7849A1023 (Black Label — Ion Rectification Amplifier)

Compatible Probe: Ionization Rods (for oil/gas flame detection); detects the presence of a flame by utilizing the principle of flame rectification.

Characteristics: No dynamic self-check function; relies on changes in flame current to determine the presence or absence of a flame; Flame Failure Response Time: 0.8–1s; Features a keyed pin configuration to prevent incorrect installation (fool-proof design).

Applications: Diesel/heavy oil burners, integrated gas burners (utilizing an ionization flame detection scheme).

III. Complete System Configuration Logic

Gas + UV Detection: RM7840L1018 / RM7840L1075 + R7861A1026 + C7061 Probe

Oil + Ion Detection: RM7800L1012 / RM7840L + R7849A1023 + Ionization Rod

Large Boiler Remote Monitoring: RM7800L1012 + Any Amplifier + S7800 Remote Panel

IV. Summary of General Parameters

Operating Environment: -40°C to +60°C; Humidity ≤ 85% (non-condensing)

Maximum Load per Unit: 2000 VA; drives ignition transformers, gas solenoid valves, and fans

Certifications: UL, CSA, and CE Industrial Safety Certifications; commonly used accessory component for the boiler industry (3C certified)