The control relay is a single pole / single throw (SPST) configuration. The control relay will energize and
the contacts will close when the process value is at or above the set point value. The control relay will de-
energize when the process value is at or below the set-point value minus the control hysteresis. This output
is used to signal the control board to turn the compressors on and off. Event input 1 of the C42 control is
utilized for the power failure alarm indication and is active by the power failure output of the control board.