Click here to Find a Contractor in your area.
Welcome! Here are the website rules, as well as some tips for using this forum.

If you've found help here, check back in to let us know how everything worked out.
It's a great way to thank those who helped you.
Need to contact us? Visit

small capacitor

I have many small ptac units that use a 2uf capacitor for evaporator blower...can I use a 4 uf in its place safely? I was always taught that you can use a smaller cap,but try not to use a larger one? so...can I use the 4uf's?


  • Eugene SilbersteinEugene Silberstein Member Posts: 1,380
    Capacitor Replacement

    When replacing capacitors, the microfarad rating of the new capacitor should not differ from the origianl by more than ten percent. Since you are dealing with 2 microfarad capacitors, installing a 4 microfarad capacitor would be increasing the capacitance by 100 percent. This can result in the overheating of the motor.

    The voltage rating on the capacitor, however, can be exceeded, as this is the dielectric breakdown voltage and not the operating voltage of the device.
  • Steve Ebels_3Steve Ebels_3 Member Posts: 1,290

    This is a motor run capacitor of more or less standard oval dimensions, Grainger has a 2mfd/370VAC in stock. It's part number 6X650 and it's 2 1/8" tall, 2 3/16" wide and 1 5/16" deep.

    Hope that helps.
This discussion has been closed.


It looks like you're new here. If you want to get involved, click one of these buttons!