Announcement

Collapse
No announcement yet.

Bad Motor or Capacitor?

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • Bad Motor or Capacitor?

    The Motor on my compressor will not run and I am wondering if it is the starting capacitor... I can rotate the motor easily enough and when I try to turn it on, the motor will start moving, but will not run...so I am asking those that know, will I be lucky enough to just have to replace the Starting Capacitor. It does not have a run capacitor, it is just a one Capacitor Motor...5HP 3450 RPM
    Walt

  • #2
    The only way I know is to test the capacitor, either with an ohm meter, or a multi-meter that has a capacitance mode. If the capacitor is open it probably won't start at all, even with no load on it. If it's shorted it may start with no load on it, but probably won't start a load.

    It's also worth noting that some motors, although they only have one can on them, the capacitor is 2 capacitors in one package, these capacitors have 3 connections/leads on them, and have 2 micro-farad (uf) ratings on them. The larger value is usually the start cap and the smaller value should be the run cap.

    Comment


    • #3
      Two things are typical- start cap goes bad, and start switch contacts go bad. I've never seen the start winding go bad, but I'm sure that does happen also. The cap has a vent, and that area should look clean and not crusted with electrolyte. It's not a guarantee that if it's clean it's good, but if it has leaked it's almost always bad. The start switch can sometimes be reached without pulling the end bell, but most often you do have to pull it- not too bad, usually you can leave the motor in place. If you take it apart, make a drawing first so you can put the wires back exactly where they came from. If you get this far and find the contacts burnt, they could probably be cleaned but it's best to replace instead. You might get lucky and find that a new cap fixes it, but if the start switch contacts are sticking you'll cook the new cap.
      I seldom do anything within the scope of logical reason and calculated cost/benefit, etc- I'm following my passion-

      Comment


      • #4
        Thank you for replying and giving me things to check out
        Walt

        Comment

        Working...
        X