Single Port 145-175 PSI Air Compressor Pressure Switch
Brand new LEFOO 140-175 PSI air compressor pressure switch control valve with a single female NPT air inlet connection port. The switch listed is a universal replacement pressure switch that replaces brands such as Furnas, Square-D and more. This switch is equipped with an unloader valve, on / off lever, and a single 1/4" female NPT air inlet port. ( Note: NPT measures about 3/4" in diameter.)
The unloader equipped on this switch is used to unload the air pressure off the head of the compressor when the compressor shuts off, this way when it starts there is no pressure on the piston and the compressor is able to start load free. This valve usually has a 1/4" plastic or copper line that runs to the check valve or the head of the compressor. If your compressor does not have an unloader line then this valve can be left not hooked up and the pressure switch will still function properly.
The preset pressure of this switch is most commonly used on two stage compressors as long as the amperage is less than 20 amps on 120 volt or 12 amps on 240 volt, however if this is being used with a magnetic starter on a larger compressor the amperage does not matter, in this case it is just used to turn the starter on & off at the set pressure.
This switch comes preset to turn the compressor on at 140 psi and shut off at 175 psi. This can be adjusted to any pressure within the factory minimum and maximum set points listed below. We have a picture showing the diagram for pressure adjustment.
• PRESET 140-175PSI
• MINIMUM ON: 50 PSI
• MAXIMUM OFF PRESSURE: 175 PSI
• PRESSURE DIFFERENTIAL: 35-55 PSI
• 1/4" COMPRESSION UNLOADER VALVE CONNECTION
• 1/4" FEMALE NPT TANK CONNECTION.
• MAX AMPS, 20 AMPS AT 120VOLT / 12 AMP AT 240 VOLT , AND 9.6 AMP AT 3PH 240 VOLT