Mars High Pressure Switch 400/200 M43329

The Mars M43329 is a high pressure switch with an approximate 400 PSI cut-out and 200 PSI cut-in.

The 200 PSI differential is unusually wide, and that width is deliberate. After a high pressure trip, the system must fall a long way before the control resets, which enforces a substantial delay before the compressor can restart.

That delay serves a purpose. A high pressure trip means the system has been operating in an abnormal condition, and an immediate restart into that condition achieves nothing beyond further stress. Requiring pressure to fall to 200 PSI ensures that time has passed and, on a system whose fault was transient, that conditions have genuinely changed.

Wide differentials appear on controls intended for applications where restarts should be discouraged. Narrow differentials appear where the control is performing an operating function and regular cycling is expected.

Reading the differential therefore tells you something about the control's intended role, which is useful when identifying an unfamiliar control on existing equipment.

Where a system trips and resets on this control repeatedly, the compressor is being subjected to a fault condition on every cycle.

Applications include commercial refrigeration, air conditioning, and heat pump systems.

Brand

Mars

SKU

M43329

Category

Pressure Switches

Weight

0.2 lbs

Dimensions

3.50" x 2.00" x 1.50"

Price

$18.00

Availability

In stock

Rating

4.6 / 5.0