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TNRIVERSIDE's avatar
TNRIVERSIDE
Explorer
Jun 01, 2015

Need help selecting the correct hard start kit for AC

After reading a lot of post on AC / generator issues I'm trying to select the correct hard start kit for my AC. I hope to pick one up tomorrow. The AC unit is an Advent 13,500 BTU. I found the wiring schematic and it showed only one capicitor. The cap has three taps labeled FAN, C and HERN. C goes to compressor "R". HERN goes to compressor "S". I assume the hard start capacitor goes across C and HERN. But I'm not sure which unit would be the best for my application. I see some that are only a capacitor and others that are an electronic unit with a relay. Any help would be appreciated.
I am using a Honda 2000I and it has started the AC unit okay so far.

8 Replies

  • kgragert's avatar
    kgragert
    Explorer
    Jun 01, 2015
    Not sure if this will help. It's a YouTube video of a SPP6 install.
    https://youtu.be/7cEaPdvzU04
  • SoundGuy's avatar
    SoundGuy
    Explorer
    Jun 01, 2015
    K.i.S.S. ... regardless of all the debate here and in any other forum discussion about hard starts caps for RV A/C use a Supco SPP6 will do exactly what you want.
  • TNRIVERSIDE's avatar
    TNRIVERSIDE
    Explorer
    Jun 01, 2015
    So if I use the SPP4e does it replace the original capacitor? If it's an e unit (smart) it seems that it would need to replace the original unit not be placed in series.
    Also, amazon says the SPP4e is not available.
  • j-d's avatar
    j-d
    Explorer II
    Jun 01, 2015
    SPP6e $23 on Amazon Prime. Saw an interesting review where homeowner removed a 5-2-1 and installed SPP8e (big home central A/C and much bigger genset) to get the A/C to start on generator. It's possible the 5-2-1 kit was sized wrong or worn out, but this suggests SPP6e is the better choice. More common, Less expensive, Easier connections.
  • Blacklane's avatar
    Blacklane
    Explorer
    Jun 01, 2015
    Air Conditioning dual capacitors usually have 3 terminals: Fan, Common, and HERMetically sealed compressor. The hard-start capacitor goes between the Common and HERM terminals.
  • j-d's avatar
    j-d
    Explorer II
    Jun 01, 2015
    SUPCO "SPP6e" or 5-2-1 "CSR U1" both available on Amazon.

    Most of us get the SUPCO and it wires across COM and HERM as you noted. SPP6e works better on RV than SPP6.

    The CSR has three wires, two across COM and HERM. plus a third wire to another point. Comes with instructions. Supposed to perform better than 2-wire units, I have not tested it and don't recall anybody here using one.

    EDIT BASED ON FRED's REPLY

    Fred - SPP4e makes sense, and SUPCO recommends the series without "e" but I go with our tech friend Chris Bryant's endorsement of SPP6e.

    OP - The non "e" SUPCO assist kits aren't "smart" like "e" series, the CSR, or an OEM relay setup.
  • Golden_HVAC's avatar
    Golden_HVAC
    Explorer
    Jun 01, 2015
    Suppco SPP4E is rated at 120 volts and anything under 3 tons.

    Also you should be monitoring your input voltage. If you are less than 108 volts, watch it very closely, and shut it off if below 105 volts.

    I plug in a voltage booster if I am below 113 volts. Many times if it is a state park, or only 30 amp services, you will need a voltage booster. But places with 50 amp wiring is much larger wire, rated at 150 amps or more, and not as likely to have a bad voltage drop.

    Good luck!

    Fred.

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