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George Marsh 01-04-2013 20:18:45 50.104.202.156 Report to Moderator	Stephen, Has anyone answered your question how to wire the contactor in the pic? What you have is a 3 phase contactor. L1,L2,L3 = 3 phase. It is possible this contactor was used on 3 phase 440v making the coil 440v. Is there any info about the coil? This is only a guess, need to confirm with an ohmmeter. The red wire is a part of the control circuit. One control leg from the pressure switch will feed in on the long red wire, goes to NC, normally closed contact, which will open if the bottom section measures too much current. The power then is sent to T4 via the other short red wire. My guess is T4 is one side of the control coil. Now use your ohmmeter and try to determine which screw is the other side of the control coil, I would try T3. If it is T3, that will be the other wire going to the pressure switch. If there is no info about coil voltage, make up a cord and apply 220v to the coil. Going to say that if you get it right, the blue section will pull inward when the coil is energized. Then all you need to do is apply 220v to L2 & L3 and wire T2 & T3 to motor. Now, don't forget to put all this inside an approved electrical box or the NEC COPS will give you a ticket and push you over a cliff. If you can't get the contactor to work and you find out how much one is going to cost you may want to double up the switch like I said above. Then put the all air compressor inside a metal container, turning it into an appliance. Then make and break one side of the 220v. The metal container will make it safer, NEC approved appliance. You may want to put a grounding rod on the metal box too. Wouldn't want to upset the NEC cops. By the way, a code is not the same as a law, except here. You can be arrested if you break a law. Never seen anyone get arrested for breaking an NEC code. If you could, I would be serving a life sentence. George [Reply]   [No Email]
Stephen Newell 01-04-2013 21:10:28 63.25.67.184 Report to Moderator	Re: Compressor electrical question in reply to George Marsh, 01-04-2013 20:18:45   I took the unit apart and found the model number of the coil and looked it up and found out it is a 110v coil. The long red wire is attached to one side of the coil. On the opposite side of the coil there is a contact A1. I'm wondering since the coil is 110v do I take power from L1 and run to A1 and then run the red wire to the pressure switch and out the other side to ground. I found a generic schematic online which runs the wire from L1 to L2 through the coil but I assume that would be for a 220V coil. If I can ever get that figured out then I have the Overload Relay to figure out. [Reply]  [No Email]
George Marsh 01-05-2013 03:48:14 50.104.202.156 Report to Moderator	Re: Compressor electrical question in reply to Stephen Newell, 01-04-2013 21:10:28   Stephen, Here is the deal, what I tell you the NEC cops will tell you is wrong, you are going to blow up the world, kill someone, kill yourself, get a ticket for breaking the law and so on. Then the advice I'm going to give you is worth what you are paying for it...... Secondly, the contactor you have is not the one that came with the air compressor. It is something so one got off a 3 phase device. That said, the bottom half of your motor contactor is not set up for your motor and I would remove it using only the top contactor. Again, NEC cops will jump all over me for saying this. I would get an extension cord and wire it to your pressure switch. Black wire on one side and white wire on the other side of the pressure switch. Use the ground wire if your 220v wire is not already grounded to the compressor. Then send the black wire from the other side of the pressure switch to A1 and the white wire to the other side of the coil. Plug in extension cord and see if contactor pulls in. If it does, you are half way home. Wire the 220v to L2 & L3 and the motor to the terminals below T2 & T3. Forget the overload protection on the contactor. I've never seen a motor that didn't already have it's own overload protection. Make sure your circuit breakers are the right size for your wire. Put the contactor in a metal electrical box. You should be good to go. Hope I've been a help. Let me know if it works. George [Reply]  [No Email]
Stephen Newell 01-05-2013 05:03:32 63.25.161.202 Report to Moderator	Re: Compressor electrical question in reply to George Marsh, 01-05-2013 03:48:14   It may perhaps be the wrong magnetic starter for my compressor but I bought the compressor new directly from Ingersol Rand and that was the switch that came with it. The motor however went out a few years back and was replaced. You are right the new motor has its own overload protection where I don't think the original motor did. I did give out some bad info about the coil being 110v. I have since learned it is 220V. I also do need to be careful not to energize the compressor itself. The compressor is used outdoors where the ground often gets wet around it. All in all with everybodies help, I'm getting closer to understanding this unit. Thankyou. [Reply]  [No Email]