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  1. #1
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    Do capacitors have a polarity?



    I know that this is a dumb question, but here goes. Basically, my central AC system from the early 2000s has been having a hard time starting up. It used to come on almost instantly, but it recently started struggling to start and browning out the lights for about 1 second when it starts up. However, once the system is running, it runs great. I checked the cap, and it was very corroded. I installed a new capacitor, and the unit starts up instantly again. The cap for the indoor blower motor seems weak too, so I went back to that HVAC shop to get a new cap for that too, and the guy warned me that they have a polarity, and the cap may work fine if connected backwards for a little while, but it can explode and start a fire with no warning. That doesnít sound right to me, but Iím far from an expert. I thought that AC caps donít have a polarity since the current alternates anyway, hence the name ďACĒ. Could someone please verify that the capacitors donít have a polarity? Thanks, I just want to make sure that I didnít screw up.



  2. #2
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    Re: Do capacitors have a polarity?

    Capacitors used in electronic have polarity.
    The capacitors we use in AC&R do not have polarity.

  3. #3
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    Re: Do capacitors have a polarity?

    Quote Originally Posted by chemi-cool View Post
    Capacitors used in electronic have polarity.
    The capacitors we use in AC&R do not have polarity.
    My understanding is that AC capacitors donít have a polarity since AC alternates, but DC capacitors have a positive and negative. Is that correct?

  4. #4
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    Brian_UK is online now Moderator I am starting to push the Mods: of RE Site Moderator : and general nice guy
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    Re: Do capacitors have a polarity?

    That's what he said, electronics are DC.
    Brian - Newton Abbot, Devon, UK
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  5. #5
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    Re: Do capacitors have a polarity?

    The HVAC shop guy is either lying to you or is incompetent.
    Mostly found in Oxfordshire, UK :)

  6. #6
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    Re: Do capacitors have a polarity?

    Only ever witnessed one explode wow how do they get all that stuff in a small tube

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