The D21-PSSR electronic controller has been designed to be a compact solution to take full advantage of our patented Air-Flow Sensor which modulates the heater’s capacity according to the quantity of air flowing through the heater by responding to the radiant heat of the elements...

A built-in control transformer is required on most heaters to supply 24 volts to the control circuits. A Class II transformer has built-in safety protection and does not require primary fusing. Primary and secondary fuses can be supplied upon request.

Used to protect the total load or individual stages. High Rupture Capacity type (HRC Form 1).