DDP Series
Air Pressure Sensing Switches

the Model DDP-105 is a general purpose proving switch designed for HVAC and Energy Management applications. the DDP-105 provides dual switching action: two separately-operated, independently-adjustable SPDT snap-acting switches are mounted on a common foot bracket. Differential pressures up to 12 inches w.c. can be measured. Because the two snap switches are set independently, an adjustable “dead- band” can be established for control circuits requiring both high and low actuation points. Many control and alarm functions are possible: for instance, monitor two pressure sources and sense the differential for actuation at two independent set points.

Each of the two plated housings contains a diaphragm, a calibration spring and a snap-acting SPDT switch. there are two low pressure sample connections (one for each switch assembly), and a common high pressure sample connection (located on the foot bracket between the two low pressure connections). All three sample connections accept 1⁄4” OD metallic tubing via integral compression ferrule and nut fittings.



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