The Daikin/McQuay 860-654873B is a microprocessor control board (MCB1) engineered for remote monitoring and centralized command of up to eight MicroTech-equipped rooftop and self-contained air conditioning units. This PC board computer manages duct static pressure control, temperature distribution, and multi-unit coordination across networked HVAC systems while maintaining independent schedule assignment and alarm oversight.
## Technical Specifications
• **Part Number:** 860-654873B (variants: 860-654873B-11, 860-654873B-06)
• **Manufacturer:** Daikin / McQuay
• **Product Type:** Microprocessor Control Board (MCB1) / PC Board Computer / Chiller Control Board
• **Power Input:** 18 Vac center-tapped from transformer T2
• **Internal Power Distribution:** 12 Vdc to LED Status Board; 5 Vdc to Keypad/Display backlight
• **Fusing:** Two 2 amp fuses in MCB power supply circuit
• **User Interface:** 12-key keypad with 2-line × 16-character alphanumeric display
• **Communication Ports:** Dual ports (A and B) with six terminals each; RS-232C and RS-485 data transmission standards supported; AMP connectors
• **Network Capacity:** Up to 8 MicroTech-equipped units; 2–8 unit groups for common duct static pressure and temperature control
• **Scheduling:** Four independently assignable schedules per unit or unit combination
• **Network Configuration:** Stand-alone operation or integration with MicroTech Network Master Panel (NMP); IBM-compatible PC with MicroTech Monitor software compatible for full-screen monitoring; optional modem support for remote telephone-line access
## Key Features
• Coordinates communications between RMC controller and unit controllers
• Emulates remote unit keypad/display via special keystroke combination
• Two hex switches for RMC network address assignment
• Microprocessor status LEDs (red, green, amber) indicate operational state
• Provides common control temperature distribution across multiple units
• Manages temperature monitoring via space or return air sensors
## Typical Applications
Multi-unit HVAC installations requiring centralized monitoring, networked unit control, and coordinated temperature and pressure management across rooftop and self-contained air conditioning systems.
## Compatibility & Integration
Works with MicroTech-equipped Daikin and McQuay applied rooftop and self-contained air conditioning units. Integrates with MicroTech Network Master Panel infrastructure and PC-based monitoring via standard RS-232C/RS-485 interfaces.
