Mars Fan Cycle Switch 150/225 M43304

The Mars M43304 is a fan cycling pressure switch with settings of approximately 150 and 225 PSI.

The 75 PSI differential between the two operating points is worth considering, because differential governs how often the fan cycles.

A narrow differential holds head pressure within tight limits but cycles the fan frequently, and frequent cycling wears the fan motor, its contactor, and the switch itself. A wide differential allows head pressure to swing more before the fan responds, which cycles less often but permits greater variation in operating conditions.

For most applications a moderate differential is the right compromise, allowing pressure to move meaningfully before the fan responds without letting it wander far outside the intended range.

Where a condenser has multiple fans, staged switches with progressively higher settings bring fans on in sequence as load increases, which gives finer control than a single fan cycling on and off and reduces the cycling frequency of each individual fan.

The settings must correspond to appropriate condensing temperatures for the refrigerant in use, established from the pressure-temperature relationship rather than applied as generic figures.

Applications include commercial refrigeration and air conditioning with air cooled condensers operating in variable ambient conditions.

Brand

Mars

SKU

M43304

Category

Pressure Switches

Weight

0.2 lbs

Dimensions

3.50" x 2.00" x 1.50"

Price

$46.00

Availability

In stock

Rating

3.9 / 5.0