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Motor starter coil question: GE CR4CJ relay

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  • Motor starter coil question: GE CR4CJ relay

    Hey guys...

    I've let the magic smoke out of my motor starter box. It has 120 volt coils in the relays but the lathe is wired for 3 wire delta configuration -i.e. there is no center tap neutral or ground to get 120 volts. For single phase it produces 208 volts from phase to phase wiring.

    My question is not about wiring the thing, seeing as how a licensed electrician ran the wires and hooked it up but my question is about finding a 208 replacement coil for the relays. My electrician tells me that they should be readily available, however the local places deal exclusively with cutler-hammer and square d. I've found some 208 coils surplus on ebay that have model number CR4XC1AE. The appear to be identical to the 110 volt coil. Is this correct? Can I purchase these specific 208 coils and replace the 110v coils with them?

    Thanks

  • #2
    Fasttrack,

    A couple of questions....
    1) Did this lathe work after the electrician wired it or did it let the smoke out on start-up?
    2) If the coils are 120 volt then either there should have been a step down transformer to get the 120 volts or there would have been a 120 volt control circuit. Do you know which?
    3) Almost all 208 or 240 volt three phase power services have 120 volt single phase available by default. To check this measure from each incoming phase wire to neutral (for testing ONLY you can measure to ground). At least two of them should measure 120 volts. The third may be 120 or High (260 volts plus) if it is high it is the 'wild leg' in a 120/240 three phase service. The phase to phase voltage should be either 230-240 OR 208. All of the above assumes that it is not a 480 volt service.
    If you have 120 volts available you should really have the electrician run a neutral wire for you then you could hook things up as they were designed. If you want to go 208 then you need to really check out the design and make sure it will work for you. As for the coils for the contactors, unless they are really old GE's you should be able to find them. The coils you found on Ebay may be the right ones. You really need to find the part number for the contactor you have and then cross reference the coils, however, if they are the right size, shape, thickness they should work .

    Get me a little more info and part numbers and I will see what I can find out for you. Also, you mentioned coils, plural, Is this a two speed or a reversing setup or both.

    Robin
    Robin

    Happily working on my second million Gave up on the first

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    • #3
      Hi Robin -

      It is a reversing box and only the forward coil blew, since that was the one I was using, but I'd like to get both working properly

      It ran for a combined total of probably nearly 4 or 5 hours but it blew when it was on continously for about an hour. I think the coil was drawing too much current and finally burned up. The "contactor" (the black box with the contacts... I'd call it a relay but I don't know the proper terminology) has CR4CJ written on it.

      There was no transformer so I assume it was supposed to be wired with a phase to neutral (120 that is) running through the push buttons and then to the coils. I guess that would be a 120 volt control circuit? I'd need to check the buttons and make sure they could handle the higher voltage, I suppose.

      This is the exact control unit on my lathe right now and the listing has some schematics if it helps. I no electrician by any means...

      http://cgi.ebay.com/GE-S-S-REVERSING...QQcmdZViewItem

      Here are the potential coil replacements I found:
      http://cgi.ebay.com/NEW-GE-MAGNETIC-...742.m153.l1262

      And yes, there is 120 available if we run a fourth wire but all the motor control boxes around have 208v coils and it would be much simpler to have a similiar box on the lathe in case it needs to be moved. The shop is 60' by 200' and it is unlikely that the lathe has found its permanent home (in the shop I mean!)

      Thanks again! I sure appreciate the help.

      Comment


      • #4
        Fast,

        I understand keeping things the same. I wish everybody thought like you . I think that the stuff you found on Ebay will work. If it were me I would just order 2 of the 208 volt contactors from the guy, at $20.00 each you will be money ahead and have spare contacts for when they fail, you might want to see about an extra coil or just order 3 contactors and keep a spare. The switches on the lathe will be fine for 208, you should check to make sure but, I have never seen an industrial switch rated less than 240 volt. Another thing, if there are any pilot lights they will need 208/240 bulbs. Also, the drawings on the Ebay item are correct for a non reversing setup, you might want to ask if they have a reversing drawing if you buy parts.
        You are on the right track for what you need to do. Just get the right coils and you are good to go. BTW that guys prices are GREAT. I have paid 5+ times what he wants.

        Let me know if you need any more help.

        Robin
        Robin

        Happily working on my second million Gave up on the first

        Comment


        • #5
          Originally posted by rdfeil
          I understand keeping things the same. I wish everybody thought like you .

          LOL nothing worse then dragging out the standard size tool chest to work on an American made car to find half of its metric and half of it SAE

          Thanks for all the help, I sure appreciate it!

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          • #6
            GE Supply's new name is Gexpro, you may try giving them a call.
            Harry

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            • #7
              Thanks for the tip!

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