Air Compressor Contactor Will Not Engage
- Thread starter peteco
- Start date
knobby
Well-known member
If the coil is replaceable sure but small DP contactors are usually inexpensive and replacing the whole contactor may be cheaper than the replacement coil by itself
Read the schematic and see if there are any devices in the coil circuit, momentaryily jumper by pass each one and observe the result; finally apply rated voltage to the coil and observe. A lot of older contactors can be manually engaged to test. Check all connections for erosion, this is a current drawing device.
Dingleburry
Well-known member
Check A1 and A2 for 120v when you think it should be running
Or disconnect and ohm out A1 to A2
Manually engage like above said, to check for free movement.
Or disconnect and ohm out A1 to A2
Manually engage like above said, to check for free movement.
Wrench97
Well-known member
That should be a pressure switch with spring control no?
OccupantRJ
Well-known member
Does the receptacle the unit is plugged into have power? That is the first step.
Yes I am pretty sure that's it. The switch is made by Siemens but the rest of the information on the label is rubbed off.
30 gallon compressor @ 120 volt probably has a pressure switch, not a contactor
they operate by tank pressure and when the pressure drops below the set level, they close & the contacts engage.
are you positive the unit is switched on?
they operate by tank pressure and when the pressure drops below the set level, they close & the contacts engage.
are you positive the unit is switched on?
sounds like it's sticky .probably best to just replace it
rlitman
Well-known member
That looks like a pressure switch / unloader to me, not a contactor. Notice that there's no coil involved. No secondary input. Just line and motor. And it's screwed into a pipe connected to the tank.
Wrench97
Well-known member
For small compressors this is what I have used > https://www.homedepot.com/p/Square-...pressor-Pressure-Switch-FHG12J52XBP/206398804