Marvair 70281 Control Board

The Marvair 70281 Control Board is a specialized 24-volt OEM electronic module engineered for Marvair ComPac, Slimpac, and Minipac vertical wall-mounted air conditioning systems. As a direct replacement for LPR-AJ1710-1 and LPR-AJ1710-2, this board manages critical system logic, including compressor sequencing, blower relay timing, and integrated safety circuits. It is designed to handle the high internal heat gains typical of telecommunication shelters and industrial equipment rooms, ensuring consistent environmental control through high-precision monitoring of pressure and temperature inputs.

This HVAC control board features onboard LED status indicators that provide real-time diagnostics for technicians, identifying operational modes and potential fault conditions such as high-pressure lockouts or low-ambient cooling adjustments. Built with advanced circuitry to optimize energy efficiency and system reliability, the board facilitates essential timing functions like delay-on-make and delay-on-break to protect the compressor from short-cycling. Its compact PCB design allows for seamless integration into the existing control box, maintaining the original factory wiring configuration for Marvair wall-mount AC units.

Key Benefits for HVAC Technicians

• Universal OEM Compatibility: Verified replacement for Marvair part numbers 70281-SP, LPR-AJ1710-1, and LPR-AJ1710-2 LF.
• Enhanced System Protection: Integrated high and low-pressure switch monitoring with built-in lockout logic prevents catastrophic component failure.
• Optimized Operational Modes: Supports advanced functions including post-purge, low-pressure bypass timing, and low-ambient control for year-round cooling.
• Simplified Troubleshooting: Bright LED diagnostics allow for rapid identification of system status without needing extensive manual testing.
• Precise 24V Control: Regulates compressor activation and fan speeds with millisecond accuracy to maintain strict temperature setpoints.

Common Questions

Is the Marvair 70281 compatible with my specific ComPac unit?
This board is the standard control module for Marvair ComPac series vertical AC units. If your existing board is labeled LPR-AJ1710-2 or 70281, this is the correct OEM replacement. Always verify your unit's data label before installation.

What do the flashing LEDs on the 70281 board signify?
The status LEDs indicate the current operating mode or a specific fault code, such as a high-pressure lockout or a sensor failure. This allows for faster diagnostics during field service calls without pulling the entire cabinet apart.

Does this board support low ambient cooling operations?
Yes, the 70281 includes integrated low ambient control logic, which is essential for maintaining cooling cycles in specialized applications like server rooms where outdoor temperatures may drop below standard operating ranges.

Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.