p45 oil pressure cut out switch HELP!
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  1. #1
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    p45 oil pressure cut out switch HELP!

    Just changed a 15 ton copeland semi hermatic in a Rudd condenser old as dirt. Dont ask why to much politics above my head. Need help cant even find m and s number so owner of the building been working on unit everything, everything wired wrong. I am putting new safetys on when I wire the johnson p45 should I tie the heater into the pressure cut out or can I use a aux contact on the compresser contactor?

  2. #2
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    If you're talking about the CCH,then, yes wire to N.C. on the aux.

  3. #3
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    10 4 THANKS

  4. #4
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    Need more help please, wiring the johnson p45nca12 oil pressure cut out. 208/230 3 phase copleand using a 230v coil relay to make and break 24 compresser contactor. Replaced it already thought I followed wire diagram on back of the cover to the oil cut out perfectly but I am obvisouly missing something.

  5. #5
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    Jun 2006
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    Quote Originally Posted by BatesTech View Post
    Need more help please, wiring the johnson p45nca12 oil pressure cut out. 208/230 3 phase copleand using a 230v coil relay to make and break 24 compresser contactor. Replaced it already thought I followed wire diagram on back of the cover to the oil cut out perfectly but I am obvisouly missing something.
    2 legs of 230 on the LOAD side of contactor goes to t2 and 230v connections. Your 24v feeding your contactor should be in series with L and M.

    I hope that helps.

  6. #6
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    and the jumper .......... does it stay between 2 and m? And L and m do they open and close my relay for the 24 v to the compresser contactor using what volt coil.....

  7. #7
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    Quote Originally Posted by BatesTech View Post
    and the jumper .......... does it stay between 2 and m? And L and m do they open and close my relay for the 24 v to the compresser contactor using what volt coil.....
    In your case...you have a 240v relay controling the 24v coil at the contactor?

    the jumper is removed if using different voltages and a 4 wire hook-up.

    L and M with jumper removed is just a switch...
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  8. #8
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    Quote Originally Posted by sprmktrefertech View Post
    In your case...you have a 240v relay controling the 24v coil at the contactor?

    the jumper is removed if using different voltages and a 4 wire hook-up.

    L and M with jumper removed is just a switch...
    to clarify....if you keep the relay then you can leave the jumper and wire 230v to the 230 term and to the one side of the relay coil the other side to M on the ofc.

    then...break your 24v control cicuit thru the N.O. contacts of your relay...or remove the relay and remove the jumper in the new oil control...and follow the directions as given by Ascj.

    what happened to the wiring diagram that came w/ the control?

  9. #9
    Join Date
    Mar 2005
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    664
    I always hated those wiring diagrams w those oil fail controls and still do! the way they tried to simplify the wiring with contactors lights controls made it a mess , stan
    Keep it simple to keep it cool!

  10. #10
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    I will take the relay and jumper out, wire line voltage to 230 on ofc and different leg to 2then L and M in series with compresser contactor. Can I test ofc by taking 24 v wire off my contactor with compresser not running I should loose my 24v signal in a 120 seconds?????

  11. #11
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    Quote Originally Posted by BatesTech View Post
    I will take the relay and jumper out, wire line voltage to 230 on ofc and different leg to 2then L and M in series with compresser contactor. Can I test ofc by taking 24 v wire off my contactor with compresser not running I should loose my 24v signal in a 120 seconds?????
    if you are to do it as mentioned above....then remember that you are taking 230v from the LOADside of the contactor and removing 24 to the coil will not allow the control to be powered....instead do one or the other:

    -remove the cap tube going to the pump. press connection and don't forget to cap it or,put your oil gauge on... unless you want an oil bath....w/the cover in place(as temp. affects the heater inside) start it up and the contacts should open in the predetermined time of aprox.2 mins.

    the other way is to use a thin blade screw driver into the slot under the trip arm to simulate no oil press diff. and energizing the heater circuit and opening the L and M...Good luck!!!

  12. #12
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    Got it I am asking these questions because I dont ever want to get whipped by one of these again thanks coach.

  13. #13
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    Hmm

    Quote Originally Posted by BatesTech View Post
    Got it I am asking these questions because I dont ever want to get whipped by one of these again thanks coach.
    Don't worry i got whipped by one as well...I bought the one the that you need to use the armored style cap tubes,and could not figure out why it always times out on oil failure....it was the schrader depressor had to be removed when using them on an oil control.LOL

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