The R200A Series3 AHU control board provides microprocessor control of a hot water or electric heat air handling unit. The board features a jumper select operation between an electric heat system or a hot water system. When selecting an electric heat system, it provides line voltage control of a fan motor or low voltage control of an ECM motor. When selecting a hot water system, it provides line voltage control of a fan motor or low voltage control of an ECM motor, line voltage control of a water pump, 24Vac control for an isolation valve and control of a dry switching relay to turn on/off a water heater. Backwards compatible with R200A (Series 1) and R200A/S2 (Series 2)
Series 3 board has an added relay (RLY4) to provide 24 VAC output to an ECM motor control board. RLY 4 (P31) operation is the same as RLY1 (P7).
Series 3 board has an Aquastat (AQ) input terminal. In Hot Water mode, if the AQ selection jumper is selected to ON, the blower (P7 and P31) is energized only after the AQ input is energized. Series 3 board has a test connection for production testing.