purpose of capacitor
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  1. #1
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    what is mechanical purpose of the run capacitor and the start capcitor?
    Start provides starting torqe and run capacitor provides current for compressor operation. is this correct?

  2. #2
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    Start Capcitor electrical storage device used to start and run circuits on many electric motors.

    Run Capacitor a device that dissipates heat generated by a motor.

  3. #3
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    capcitors

    Originally posted by framehvac
    Start Capcitor electrical storage device used to start and run circuits on many electric motors.

    Run Capacitor a device that dissipates heat generated by a motor.

    can any one verify this info as being correct?

  4. #4
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    Yes I will.HaHa

  5. #5
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    Re: capcitors

    Originally posted by jgb123
    Originally posted by framehvac
    Start Capcitor electrical storage device used to start and run circuits on many electric motors.

    Run Capacitor a device that dissipates heat generated by a motor.

    can any one verify this info as being correct?
    meant to ask " can anyone else verify this as being correct?"

  6. #6
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    Re: capcitors

    Originally posted by jgb123
    Originally posted by framehvac
    Start Capcitor electrical storage device used to start and run circuits on many electric motors.

    Run Capacitor a device that dissipates heat generated by a motor.

    can any one verify this info as being correct?
    Close enough.

  7. #7
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    you @framehvac could both get help from an electronics course. Learning fundementals is essential before understanding the rest.
    there is no mechanical job of a capicitor.its electro-magnetic. It doesnt release heat either
    never say never

  8. #8
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    Feb 2005
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    Originally posted by contactor
    you @framehvac could both get help from an electronics course. Learning fundementals is essential before understanding the rest.
    there is no mechanical job of a capicitor.its electro-magnetic. It doesnt release heat either
    So what is the purpose of a run capacitor and a start capacitor in a condensing unit in relation to the compressor? did not think it absobs heat from the motor.

  9. #9
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    OK, the start cap's purpose is to cause a phase angle shift during the starting of the motor to increase the efficiency of the start winding, it, and the start winding, have to be out of the circuit when the motor is at full speed, or will burn. This is often accomplished with the potential relay, but could also be done with a centrifugal switch.


    The run cap does the EXACT same job, but is left in the circuit during motor operation, charging and discharging constantly. It DOES reject heat, but only it's own heat, created by that constant charging and discharging, not that of the motor winding. The run caps are usually built tougher, to take higher heat, but are not heat sinks.

    Happy?

    Hey, you asked............

  10. #10
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    Originally posted by jgb123
    Originally posted by contactor
    you @framehvac could both get help from an electronics course. Learning fundementals is essential before understanding the rest.
    there is no mechanical job of a capicitor.its electro-magnetic. It doesnt release heat either
    So what is the purpose of a run capacitor and a start capacitor in a condensing unit in relation to the compressor? did not think it absobs heat from the motor.
    Often, in a condensing unit, the run cap ill be for the fan motor.

    The compressor will be started with a start capacitor and potential relay.


  11. #11
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    Feb 2005
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    15
    Originally posted by condenseddave
    OK, the start cap's purpose is to cause a phase angle shift during the starting of the motor to increase the efficiency of the start winding, it, and the start winding, have to be out of the circuit when the motor is at full speed, or will burn. This is often accomplished with the potential relay, but could also be done with a centrifugal switch.


    The run cap does the EXACT same job, but is left in the circuit during motor operation, charging and discharging constantly. It DOES reject heat, but only it's own heat, created by that constant charging and discharging, not that of the motor winding. The run caps are usually built tougher, to take higher heat, but are not heat sinks.

    Happy?

    Hey, you asked............
    Thank you for the info, so the run capactor remains in the circuit to keep compressor running after the compressor reaches full speed, correct. would this be a way of explaining this on a test, still in school and studying for exam.

  12. #12
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    East Stroudsburg, PA
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    On a capacitor-start-capacitor-run motor, which is not real common for a compressor, yes.

    A Permanent Split Capacitor motor is the most common application for the run capacitor.

    In the PSC motor, the run cap actually assists in starting the motor, and then increases the efficiency of the motor while it's running by causing the phase angle shift.

  13. #13
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    Some of these replys give that "deer in the headlight" look.

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