The Coil Protection Lockout Switch, MODEL CPLS, is a temperature sensing control, used
to act as a safety against Evaporator Coil freeze up. It is designed to mount on the surface
of a 3/4" or 7/8” suction line. Electrically, it is wired in series with the "Y" lead from the
thermostat or zone control panel, to the compressor contactor coil or relay. The switch
breaks (opens) shutting off the compressor when the temperature of the pipe drops below
37 F. The switch will reset (close), restarting the compressor when the temperature of the
pipe rises above 47 F. EWC strongly recommends installing a compressor time delay
relay when a CPLS control is used.