How to Go from a Dual Capacitor to a Single in a Air Conditioner

By | April 16, 2020

How to Go from a Dual Capacitor to a Single

I have been asked a few times about wiring up a single capacitor when a dual round has failed.

First of all I dont suggest doing this and it is only a quick fix when you dont have the correct dual round capacitor with you.

With that said this is done all the time by HVAC technicians and you may find yourself working on a unit that has been fixed this way.

Wiring up a single capacitor is easy if you simple remember that a dual round is two capacitors in one package.

The common Leg is shared while the other legs go to separate components.

Since a dual round shares the common leg there is only three connections. A jumper wire will need to go to the common leg on the single capacitor.
How to Go from a Dual Capacitor to a Single Capacitor
A Dual Round is two capacitors in the same package which can be separated into single units.

Often what happens in an A/C unit is one side will fail while the other is good, so a tech will simply wiring a single to replace the bad side.

For example, most all dual rounds will have a capacitor for the compressor and one for the condensing fan motor.
How to Go from a Dual Capacitor to a Single Capacitor 2017
If the compressor side capacitor in the dual round is good but the fan side fails, the fan side can be replaced with a single.

Since the compressor side capacitor is good it will stay connected and working.
Wiring in a single capacitor to replace a dual is easy to do with some basic understanding.

A jumper wire will need to be installed to carry the common wire to the added capacitor since a dual round will share this leg.

Also be sure to match the MFD and voltages to the correct components.

Remember always install the correct components unless you have no other options.



2 thoughts on “How to Go from a Dual Capacitor to a Single in a Air Conditioner

  1. Anthony McMahon

    I have installed a new condensor fan motor 51-23055-11 and it came with a 3uf fan capacitor. My old motor was a 3 wire and the new is a 5 wire. I installed the motor using the black brown and orange wires and joined the yellow and purple together with a wire nut and everything is up and running. I have not installed the I believe required single run capacitor but wired everything to the dual run capacitor,. Once again everything is running. I want to properly install the single 3uf capacitor and leave the dual run for the compressor side. I believe I should take the brown fan wire from the motor and put it on the 3 uf capacitor but I am not sure if I should take the orange new motor wire off of the dual run capacitor and put it on the 3uf or put a jumper from the dual common to the new 3uf. Please advise ? Your video was somewhat helpful but went to fast when showing your hookup.

  2. Elizabeth A Leac

    Hello, I seem to have a strange setup. I need to replace the contactor and capacitor in my unit. When I opened the box, I found two single capacitors; one round with two prongs and one oval with two prongs. Do I have to continue using two singles or can I go to a round dual capacitor? Thank you.


Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.