Tjernlund PS-1505 Fan Proving Pressure Switch

The TJERNLUND PS-1505 Fan Proving Pressure Switch verifies inducer fan operation before ignition in draft inducer venting systems, ensuring safe operation of gas- and oil-fired heating equipment. Commonly installed on furnaces, boilers, unit heaters, and other heating appliances equipped with AUTO-DRAFT draft inducers, it serves as a draft inducer safety interlock in residential, commercial, and light industrial HVAC systems. It features SPST normally open snap-action contacts with a 125 VA pilot duty rating at 24 VAC and 300 VA at 115–277 VAC, a maximum switching current of 15 A non-inductive at 277 VAC, and a fixed, non-adjustable control set point. The operating pressure is 0.05 ± 0.02 in. W.C. increasing vacuum, with a maximum pressure of 1/2 psi, and the diaphragm is mounted vertically. Electrical connections are #6-32 screw terminals with cup washers, and the operating temperature range is -40°F to 190°F (-40°C to 88°C). Manufacturer is TJERNLUND, part number PS-1505, product type Fan Proving Pressure Switch. For retrofit or replacement, common substitutes include TJERNLUND PS-1506, Cleveland Controls NS2 Series, and Dwyer 1950 Series.