Need some help wiring magnetic starter for compressor

[lzicc]

I moved my compressor to my new house and got confused on the wiring for the magnetic starter. The compressor will not run. The wire coming from the fuse box comes in through the top and connects to L1 and L2. The wire coming from the motor comes up through the bottom and connect to T1 and T2. The wires coming from the pressure switch comes in from the left of the picture and one wire is connected to L1 and the other wire goes to the lug behind it which I guess is 1. I am pretty sure this is how it was connected. If you look at the wire on the right which is a thin black wire, it came out when I disconnected it and I am not sure where it should go. Right now I have it in the same lug as the one pressure switch wire is in on lug number 1. I'm not even sure what that wire is for. I have a power test light and I get power on L1 and 2 which is obvious, I get power from both of the pressure switch wires, but no power going to the motor wires which are T1 and 2, so it seems like the switch is not engaging. The model number of the switch is 100-NX66H. I believe Allen Bradley is the maker, but I cannot find any info on the net for this switch. Any help would be appreciated. I did let the air out of the tank, so it has nothing to do with the pressure being too high for it to come on.

 

[mrb]

incoming power should go to L1 and L2. The jumper from 14 to L2 should stay. The pressure switch should be connected between L1 and 13

 

[lzicc]

Thanks for the reply MRB. 14 (the black jumper wire) is currently going to L1, not L2 and it is on a lug that is behind L1. Not sure if they are the same, but they are 2 different screws. The lug 13 was never used before. I just checked, and the screw was very tight, so there was never a wire in there before, so I hesitated putting that wire in there, but I see the symbol like something should go in there to complete switch. All the connections I disconnected I left loose and 13 with a few others were tight like they were never used before. I just don't want to make a mistake.

 

[mrb]

ok sorry my mistake. 13 and 14 are aux contacts. There should be two contacts behind the front of the thing, A1 and A2. Those are the coil. Basically you need power going to L1 and L2. One side of the coil should be connected to L2. The other side of the coil connected to the pressure switch. The other wire from the pressure switch connect to L1.

and bond the can that contactor is in.

 

[mrb]

i also just noticed you dont appear to have an overload. How many HP is this compressor?

 

[Stuart in MN]

I just looked through the Allen-Bradley website and found bulletin 100 contactors, but didn't find a 100NX66H. I'm guessing it's an old model that's been superceded by a newer version.

Based on the information on the contactors they sell now, I think terminals 13 and 14 are for a set of auxiliary contacts. They would be used to turn on an indicator light or something like that. The terminals for the contactor coil (the part that pulls the contacts in to energize them) don't appear to be visible in the photo - there should be two more terminals we can't see on the side or top, probably labeled as A1 and A2. The question is what voltage the coil is supposed to run on - it could be 120vac or 240vac, hopefully that's marked on it somewhere.

If it's a 240vac coil, it should be hooked up like this:

L1-----pressure switch-----A1 and A2----L2

If it's a 120vac coil, it should be hooked up like this:

L1-----pressure switch-----A1 and A2----N (neutral)

 

[lzicc]

It is 5 HP. I saw 208V on the switch.

A1 is on a lug that is behind L1 and A2 is on a lug behind 14.

If you look at the pic below, you can see the white and black wire in the very back of the pic. That is A1. I have the jumper wire that comes from A2 into A1. There is also another wire in A1 that is one of the wires from the pressure switch.

In this picture of the bottom, the black wire that jumps around on the right is A2 which I have going to A1.

The picture below is a side view of the switch.

 

[lzicc]

Stuart, I set the wires up like you suggested and it worked. Thank you and MRB for your help, it is much appreciated.

 

[Stuart in MN]

Good deal!