120V Modulating Control with Valve Proving System (VPS) Capability
The Honeywell RM7890B2048 is a microprocessor-based modulating primary burner control designed for single-burner applications firing gas, oil, or combination fuels. It provides integrated burner sequencing, flame supervision, system diagnostics, and safety shutdown. This model includes built-in compatibility for a Valve Proving System (VPS), enhancing system safety by verifying valve integrity before burner start-up.
Technical Specifications
- Model: RM7890B2048
- Series: RM7800
- Product Type: Modulating Primary Burner Control
- Voltage: 120V AC (+10%, -15%)
- Frequency: 50/60 Hz (±10%)
- Application: Single-burner gas, oil, or combination fuel systems
- Pilot Type: Intermittent
- Flame Detection: UV, IR, or rectification (depends on amplifier)
- Flame Amplifier Compatibility: R7847, R7848, R7849, R7851, R7861, R7886
- Flame Establishing Period – Pilot: Typically 4 to 10 seconds
- Flame Establishing Period – Main: Intermittent
- PrePurge: Required (set via ST7800A Purge Timer)
- Delayed Main Valve: Yes (with VPS logic)
- VPS Capability: Integrated
- Mounting: Requires Q7800A or Q7800B Subbase
- Weight: Approx. 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
- Operating Temperature: -40°F to +140°F (-40°C to +60°C)
- Condition: New
Key Features
- Integrated microprocessor-based flame safeguard and burner sequencing
- Compatible with Valve Proving System for added safety
- Supports intermittent pilot and modulating burner configurations
- Stores lockout history and operating hours in nonvolatile memory
- LED indicators provide burner sequence and fault status
- Optional remote display, annunciation, and PC interface
- Supports report generation and remote reset capability
- Compatible with Honeywell’s full line of plug-in flame amplifiers
Compatible Accessories
- Q7800A / Q7800B Universal Subbase
- ST7800A Purge Timer Card
- R7847, R7848, R7849, R7851, R7861, R7886 Flame Amplifiers
- S7800A Keyboard Display Module
- Flame rods, UV and IR flame scanners
- DATA CONTROLBUS™ and Combustion System Manager™ Software
Industry Applications
- Industrial boiler systems
- Packaged burners and furnaces
- Commercial heating plants
- Process heating with enhanced safety requirements
Installation & Maintenance Notes
- Install using approved subbase and purge timer
- Use correct flame amplifier and sensor for burner type
- Enable VPS logic per wiring configuration and system design
- Review LED indicators and diagnostics for lockout causes
- Monitor system performance and flame signal strength regularly