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How to wire "new" contactor to momentary switch

Discussion in 'ELECTRICAL ISSUES - POWER YOUR MACHINES & SHOP' started by Reeltor, Jul 17, 2017 at 5:11 PM.

  1. Reeltor

    Reeltor United States Active User Active Member

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    I need help wiring my shaper. Previous owner(s) cut and removed the contactor.
    Here is what I have, a 16" G & E shaper with a 5hp 3-phase motor.
    On the machine there is a momentary type push button on/off switch, the wiring appears to be in the main housing with the oil and gears (but I cannot see or get to where the wire enters the switch to replace it).
    There is a Main Disconnect with 3-cartridge fuses (one for each phase), I have acquired a "newer" if not NOS contactor (or is this called a starter?) GE CL45

    The push button switch on the shaper has 4-lugs, 1,2 &3 were used with #4 empty.

    Photos of the parts are attached, what voltage is going to the switch? Normally, I wouldn't worry about it but the wiring exposed to the lube oil is a concern and I would prefer a low voltage on/off if possible. At this point I don't have a clue if the motor works, but it is a cool old motor and would like to keep it.

    thanks,

    Mike

    GE CL45 face.JPG cl45 upper side A1-A2 connectors.JPG cl45 lower side A2 connector.JPG Westinghouse push button station.JPG push button leads 1-2-3, 4 empty.JPG shaper motor nameplate.JPG View attachment 237834 CL45 nameplate.JPG
     
    Last edited: Jul 17, 2017 at 6:13 PM
  2. jim18655

    jim18655 United States Active User H-M Supporter-Premium

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    Need the coil voltage of the starter.
    Is there a transformer in the machine? (Probably not)
    You need to find a 3 wire control diagram to follow the wiring.
    Looks like a contactor only without overloads.
    More to follow.
     
  3. Reeltor

    Reeltor United States Active User Active Member

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    If there was a transformer on the machine it is long gone, there is a 110v transformer for a light circuit. I do have another old contactor, I'll shoot a photo or two of it. It might be a better choice.

    Mike
     
  4. jim18655

    jim18655 United States Active User H-M Supporter-Premium

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    Try to get a better picture of the full tag on the contactor above. I can't read it due to the glare.
     
  5. Reeltor

    Reeltor United States Active User Active Member

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    photo of tag has been replace in original post
     
  6. British Steel

    British Steel United Kingdom Active User Active Member

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    Hi Mike,

    It looks like the plastic moulding between the A1 and A2 terminals bears the legend "208v 60 Hz" - if so that's your coil voltage and it would go across Neutral and one phase of the incoming 4-wire=plus-earth(ground) 3-phase, BUT what it doesn't have is an auxiliary contact to "latch" the contactor - the four slots on top are probably where additional aux' contact sets can mount.
    What you will need for that contactor is a normally-open (NO) contact set to mount on top (probably manufacturer- and contactor-size-specific), then feed one 208v phase to one terminal of the contact set, onwards out to your green push-button (check it's push-to-make), wire other side of the push-button comes back and goes to A1 as does the other terminal of the NO contact set, then the A2 connects to neutral through a normally-closed (your red) pushbutton.

    When you push the green NO button, it will apply 208v across the coil (the A1, A2 terminals), which will pull in the NO contacts and also operate the NO aux set, which will then maintain power to the coil and latch the contactor so you can let go of the button. When you push the red, it will break the coil's return to Neutral, no current will flow and the contactor will drop back put until you release the red and prod the green again - this will also give you no-volt-release, so if the power's lost the machine won't restart on its own, it'll wait for you to push the start button again :)

    Ideally you should add a motor overload rated for the motor's full-load amps, between motor and contactor, and if that has an aux' contact set on it use that to break the neutral return if the overload trips, and it may be easier/quicker/cheaper to buy another contactor (EvilBay's good for this sort of thing) that already has the NO contact built in...

    Hope that helps a little,
    Dave H. (the other one)
     
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  7. British Steel

    British Steel United Kingdom Active User Active Member

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    Oh, if you want to go low-voltage on the control circuit (a good idea, safer by a mile!), all the above applies, but put a 208-24v control transformer between incoming 208v and Neutral (with a fuse on the high voltage side!) and run the transformer's 24v output through the same way, using a contactor rated for your motor power with a 24vac coil.

    Dave H. (the other one)
     
  8. Reeltor

    Reeltor United States Active User Active Member

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    OK, the contactor that I have won't do the job.

    If I go to eBay to look for what I need, what search terms should I use? I was able to wire up my RPC panel box to the lathe and mill without a problem but this (what I called a magnetic switch) is a first time for me.

    here is an old contactor that I got with a craigslist purchase, it was connected to a 5-hp motor that I gave to a friend.
    Is this something that can be used?
    old contactor rotated.JPG
     
  9. Ulma Doctor

    Ulma Doctor Infinitely Curious Active Member

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    if you are serious about wanting to use the new 4 pole contactor listed in post 1 above, i can show you a latching circuit that uses momentary switches (1 NO start, and 1 NC stop)
    if both the start and stop switches that are already present are NO for the start and NC for the stop- it will be a slam dunk
    if your switches are somehow any different than NO and NC respectively, there is still hope- i just may need to modify the plan of attack

    i'm sorry for the poor quality of the scan but i hope the idea lands...
    (the overload and control fuses are omitted for simplicity)
    latching circuit.jpg
     
    Last edited: Jul 18, 2017 at 9:47 AM
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  10. killswitch505

    killswitch505 United States Active Member Active Member

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    The problem with using the contactor in the picture you'll not have any over current protection not a big deal if you like living on the edge. Also it looks to me like it's a 3 pole to me. Not counting A1 and A2 I'm only seeing 6 screws/lugs 3 on top and 3 on bottom. If that's the case you need a 4 pole or you might be able to add a NO aux to the side of it. I'm not sure the size or the motor your running more than likely you need what's called a size zero motor starter and you need a 208/240 coil unless you got your heart set on low voltage that's gonna open a different can of warms. The guy above me drawing is good if it's a four poll contactor. It's not drawn how I would draw it his way would actually be easier to understand.
     
  11. British Steel

    British Steel United Kingdom Active User Active Member

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    Hi Mike,
    If EvilBaying you want either a 4-pole or 3-pole-with-NO-aux (may be listed as "3NO+NO" or similar), and it must be rated for the motor - motors are the "AC3" rating in kw or hp marked on the contactor - this will be the LOWEST marked as motors/transformers are inductive and Hard Work, generating high voltages when the load current' S interrupted with bigger arcs at the contacts...
    If you want to be extra safe, 24v control circuits can't fry you, you'll need a 24v a.c. coil contactor and a 208-24v control transformer rated about 50 va - and as suggested, a motor overload that sits between motor and the contactor, either fixed for your motor's full load amps or with an adjustment covering that current - the setting is such that it'll run at FLA but trip 20 - 30% above, saving the motor.
    Check the motor voltage is right for your supply or it can be wired for it, and if it's never run in your sight check it for opens, leakage to earth etc!

    Dave H. (the other one)
     
  12. Reeltor

    Reeltor United States Active User Active Member

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    Guys, thanks for the input and ideas. I will need some time for this info to sink in.
    Let me ponder and I'll be back with questions.

    Thanks again
     

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