A pressure differential switch is used to prevent a heater from operating if there is no airflow across the heating elements. The switch is provided with a pitot tube to be installed into the duct, which makes it sensitive to velocity pressure as well as to static pressure. In ap...

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.

Pneumatic-electronic transducer. The P37 is a Pneumatic-electronic transducer that converts a 2-13 psi input into a proportional Pulse or 0-10VDC output and therefore replaces both the P35 and P36. For ease of use the board is programmed for 3-8 psi Pulse output selectable from ...