RM7850A1019 Burner Control Module: Reliable Flame Safety Management

Core Technical Specifications

• Brand & Model: Honeywell RM7850A1019 (RM7850 series). Burner programming control category. Supplied by Ubest Automation.
• Voltage & Frequency: 120 Vac (+10%, -15%). Supports 50 Hz or 60 Hz (±10%).
• Flame Establishing Period: Pilot: 3 or 5 seconds. Main: 3, 5 seconds, or intermittent.
• Post-Purge Timing: Fixed 15 seconds. Pre-purge depends on ST7800A plug-in timer card.
• Interlocks: Lockout type with preignition enabled. Airflow check is user selectable.
• Pilot Type: Interrupted with second stage pilot valve running intermittent duty.
• Temperature Range (Operating): -40°C to +60°C (-40°F to +140°F). Storage down to -40°C to +66°C.
• Humidity & Vibration: Handles 85% RH noncondensing continuously. Withstands 0.5G vibration.
• Dimensions & Weight: 127 x 127 mm base. Depth varies by subbase: 133 mm (Q7800A) or 155 mm (Q7800B). Weighs 0.73 kg (1 lb 10 oz).
• Power Dissipation: Relay module draws max 10W. Optional KDM uses 3W. Total connected load up to 2000 VA.
• Fusing: Requires 15A type SC fuse or equivalent for total load protection.
• User Interface: Five LEDs show sequence status. One five-function Run/Test switch simplifies diagnostics.
• Flame Amplifier Compatibility: Works with plug-in amplifiers: R7847, R7849, R7861, or R7886.
• Memory & Fault Logging: Nonvolatile memory retains history files and lockout status after power loss.
• SIL 3 Capable: Suitable for Safety Instrumented Systems when properly designed (see form 65-0312).
• Approvals: Factory Mutual (J.I.0Y0A9.AF), GASTEC (CE-63AP3070/1), and EN298 certified. Complies with Gas Appliance, Low Voltage, and EMC Directives.

Installation Guidelines

• Mount the RM7850A1019 on a Q7800A or Q7800B universal wiring subbase. The subbase provides all field wiring terminals.
• Install a compatible plug-in flame amplifier (R7847, R7849, R7861, or R7886) into the relay module.
• Insert the ST7800A plug-in purge timer card to set pre-purge duration. Choose the card that matches your application.
• Connect the flame detector per Table 7 in Honeywell documentation. Use the correct detector for your fuel type.
• Apply power at 120 Vac (+10%, -15%) only. Use a 15A type SC fuse on the total connected load line.
• Verify all external voltage check points before startup. The design allows easy probe access.

Frequently Asked Questions (FAQ)

• Q: Does the RM7850A1019 work with existing Honeywell flame detectors?
  A: Yes, it is compatible with most Honeywell flame detectors. Choose the correct plug-in amplifier from Table 7.
• Q: What shipping carriers do you use?
  A: We ship via FedEx, UPS, or DHL depending on your location and order urgency.
• Q: Can I use this module for 220-240V systems?
  A: No, the RM7850A1019 requires 120V. For 220-240V, order EC7830 or EC7850 series instead.
• Q: How do I check fault history after a lockout?
  A: The nonvolatile memory retains fault logs. Use an optional keyboard display module (KDM) or external annunciation.
• Q: Is the RM7850A1019 suitable for safety-critical systems?
  A: Yes, it is SIL 3 capable in a properly designed Safety Instrumented System. Review Honeywell form 65-0312.

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