Microprocessor-Based 120V Flame Safeguard for On-Off Burners

The Honeywell RM7890B2030 is a primary burner control designed for single-burner applications firing gas, oil, or combination fuels. This microprocessor-based module offers dependable burner sequencing, flame supervision, and safety shutdown functions. It supports standard prepurge operation and integrates seamlessly with Honeywell’s RM7800 series subbases and flame amplifiers.

Technical Specifications

  • Model: RM7890B2030
  • Series: RM7800
  • Product Type: Primary Burner Control
  • Power Supply: 120V AC (+10%, -15%), 50/60 Hz
  • Application: On-Off Single Burner Control
  • Flame Establishing Period – Pilot: 4 or 10 seconds
  • Flame Establishing Period – Main: Intermittent
  • Interlocks: Selectable
  • PrePurge: Determined by ST7800A Purge Timer Card
  • Delayed Main Valve: No
  • Pilot Type: Intermittent
  • Airflow Switch Check: Included
  • Mounting: Requires Q7800A or Q7800B Subbase
  • Flame Amplifier Compatibility: R7847, R7848, R7849, R7851, R7852, R7861, R7886
  • Certifications:
  • UL Recognized – File No. MP268
  • CSA Certified – File No. LR95329-3
  • FCC Part 15, Class B Emissions
  • Weight: 1 lb 15 oz (0.9 kg)
  • Dimensions (with Q7800A): 5″ W x 5″ H x 5-1/4″ D
  • Dimensions (with Q7800B): 5″ W x 5″ H x 6-3/32″ D
  • Shipping & Storage Temperature Range: -40°F to +140°F (-40°C to +60°C)
  • Condition: New

Key Features

  • Microprocessor-controlled sequencing and diagnostics
  • Compatible with all standard Honeywell plug-in flame amplifiers
  • Optional keyboard display, remote annunciation, and reset
  • Nonvolatile memory retains history and status after power loss
  • Five onboard LEDs display sequence and lockout information
  • Suitable for gas, oil, or combination-fuel systems

Compatible Accessories

  • Q7800A or Q7800B Subbase
  • ST7800A Purge Timer Card
  • R7847, R7848, R7849, R7851, R7861, R7886 Flame Amplifiers
  • S7800A Keyboard Display Module
  • Flame rods, UV and IR flame detectors

Industry Applications

  • Commercial and industrial burners
  • Process heating systems
  • Steam and hot water boilers
  • Fuel-fired HVAC and manufacturing systems

Installation & Maintenance Notes

  • Install with correct subbase and verify flame amplifier compatibility
  • Set purge timing using ST7800A card
  • Monitor status with built-in LEDs or optional display
  • Test flame signal strength during startup
  • Review stored lockout and history data during service

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