Mars Fan Cycle Switch 300/400 M43307

The Mars M43307 is a fan cycling pressure switch with settings of approximately 300 and 400 PSI.

Settings in this range suit systems operating with higher pressure refrigerants, where normal condensing pressures are substantially above those of the refrigerants these controls were originally developed for.

This is a point that recurs across every pressure control in a refrigeration system, and it is worth stating plainly: when equipment is converted to a different refrigerant, every pressure control in it must be reviewed.

The reason is that pressure controls act on pressure, but what they are actually managing is temperature. A high pressure safety is protecting against excessive condensing temperature. A fan cycling control is maintaining adequate condensing temperature. A low pressure control is preventing operation at excessively low evaporating temperature. In each case the pressure that corresponds to the relevant temperature changes with the refrigerant.

Controls left at their original settings after a retrofit will therefore act at the wrong temperatures, and the consequences range from nuisance trips through to a safety that no longer protects.

Applications include commercial refrigeration and air conditioning with air cooled condensers using higher pressure refrigerants.

Brand

Mars

SKU

M43307

Category

Pressure Switches

Weight

0.2 lbs

Dimensions

3.50" x 2.00" x 1.50"

Price

$41.00

Availability

In stock

Rating

0 / 5.0