how to wire a compressor pressure switch?

[slickrock]

Just picked up a new pressure switch for my OBA and it is a different one than I have used in the past.

It is the type that normally goes on a 110V or 220V (big square type Square D) but I have seen them used on OBA systems in rigs. There are 4 connectors on the back: L1 T1 T2 L2. Which ones do I use to run the power to my compressor. (which 12v positive do I run in and which do I run out of and does it need to be grounded)?
Thanks, Dan

Can I jsut run 12v from the battery to L1 and t1 goes to the pump power?

 

[Pin_Head]

You can use either T1 and L1 or T2 and L2; your choice. The power supply wire should be fused (the engine fuse would be OK) and go to T1. Then a wire from L1 goes to the compressor.

Whether you need a ground wire depends on what type of compressor. If the compressor clutch is grounded, then no wire is needed as long as the compressor case is grounded. If the compressor has two wires then run the ground wire to a good ground, like the frame, to compete the circuit.

 

[slickrock]

You can use either T1 and L1 or T2 and L2; your choice. The power supply wire should be fused (the engine fuse would be OK) and go to T1. Then a wire from L1 goes to the compressor.

Whether you need a ground wire depends on what type of compressor. If the compressor clutch is grounded, then no wire is needed as long as the compressor case is grounded. If the compressor has two wires then run the ground wire to a good ground, like the frame, to compete the circuit.

Thanks for the reply. I have the ground off of the compressor gounded to the battery. I was not sure about the Square D switch. Slickrock