Question 1

What is an air compressor pressure switch?

Accepted Answer

It is a control device that starts and stops a compressor according to receiver pressure.

Question 2

What does cut-in pressure mean?

Accepted Answer

Cut-in pressure is the lower pressure point where the compressor starts again.

Question 3

What does cut-out pressure mean?

Accepted Answer

Cut-out pressure is the upper pressure point where the compressor stops.

Question 4

Why does a compressor not stop running?

Accepted Answer

Common causes include incorrect settings, a failed pressure switch, leaks, insufficient compressor capacity or a blocked pressure sensing port.

Question 5

Why does a compressor not start?

Accepted Answer

Possible causes include no power, tripped overload, faulty switch contacts, low voltage, failed capacitor or motor fault.

Question 6

Why do pressure switch contacts burn?

Accepted Answer

Contacts may burn from overload, frequent cycling, loose wiring, contamination or using an undersized switch.

Question 7

What is an unloader valve?

Accepted Answer

An unloader valve releases trapped head pressure after the compressor stops so the motor can restart more easily.

Question 8

What is a 4-way pressure switch?

Accepted Answer

A 4-way switch has multiple ports for fittings such as gauges, safety valves, outlet connections and unloader lines.

Air Compressor Pressure Switch Technical Resources

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