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Hvac

mmc239
mmc239 Member Posts: 94
in A-C, Heat Pumps & Refrigeration
Hi. I am trying to change my capacitor on my central Ac unit. It is rusted on top and I can't see which terminal is herm, C, etc. how do I figure out which wire goes where?

Comments

  • ratio
    ratio Member Posts: 3,777
    The "c" terminal goes to the contactor, the "fan" to the fan, & the "herm" to the compressor.
  • mmc239
    mmc239 Member Posts: 94
    Will I have to trace each wire back to each device? The old capacitor is rusted and I can't read the terminals.
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 16,365
    best bet would be to trace each wire, then you know it's right
  • JUGHNE
    JUGHNE Member Posts: 11,266
    You can look at the wiring diagram that might be on the inside of the cover. It may give you colors which may still be visible on the wires.
    Also I would install new connectors on the ends of the wires.
  • Techman
    Techman Member Posts: 2,144
    I've been tracing out wires on rusted caps for 4+ decades. So, join the club!
  • newagedawn
    newagedawn Member Posts: 586
    check the schematic it will tell you what wire goes where, typically the brown with white is the herm
    "The bitter taste of a poor install lasts far longer than the JOY of the lowest price"
  • HVACNUT
    HVACNUT Member Posts: 6,283
    Is there a problem with the condenser, or you just want to change it? Do you have an RMS multimeter to read Uf?
  • JUGHNE
    JUGHNE Member Posts: 11,266
    The homeowner could buy several capacitors (condensers) for the price of the RMS meter for MFD checking.
    I wonder how the rust ended up on the top unless rain got into the box. The crimp on connectors should be changed also IMO.
  • mmc239
    mmc239 Member Posts: 94
    Will the schematic be located near the capacitor?
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 16,365
    It's usually attached to the inside of the cover. If not you may be able to Google the unit to find it. Or just snip the wire tys and trace the wiring
  • JUGHNE
    JUGHNE Member Posts: 11,266
    If this AC has some years on it the contactor in the same box/area you are showing may be worn out also.
    Has water gotten into the capacitor area?
    The crimp on connectors are aged and should be changed.
    Your contactor contacts may be burned/pitted, you can not always seem without taking off a small arc guard cover.
  • HVACNUT
    HVACNUT Member Posts: 6,283
    Still wondering if this is an operating problem or preventive maintenance?

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