R401

The R401 specification describes a configurable microprocessor heat pump control board for water source heat pumps. Operating environment is -20 F to 140 F and up to 90 percent RH non-condensing. Storage is -30 F to 150 F at the same humidity limit. Power draw for the board alone is a nominal 5 VA at 24 Vac and a maximum 9 VA. The sheet calls for a dedicated 24 Vac, 50-60 Hz, single-phase transformer of 40 VA minimum for a typical water source heat pump application. The board is grounded through two metal standoffs.

Relay ratings are a compressor relay of 40 VA at 24 Vac, and alarm, fan, accessory, and auxiliary heat relays at 28 VA at 24 Vac. Features include anti-short cycle protection, high- and low-pressure cutouts, water-coil and air-coil low temperature cut-out, random start, and a diagnostic LED. Dip switches leave the factory off. Jumpers select a 30 F or 10 F coil cutout. Delays include a random start of 5 to 80 seconds and a 5 minute anti-cycle delay. Display codes include St for standby, FO for fan only, CO for cooling, and H1 for heating.