Fit Check on every partFree shipping over $4930-day returns
Help: contact us
HVAC FitterTHE PART THAT FITS
CAPACITORS · 5 MIN READ

Condenser for a cooler motor: how to match the run capacitor

A cooler motor condenser is its run capacitor. Match the µF exactly and the volts same or higher, and check the motor really uses one.

By the HVAC Fitter teamUpdated October 22, 2026
THE SHORT ANSWER

"Condenser" is the old name for a capacitor. On a cooler or fan motor it means the run capacitor: the small can wired to the motor.

  • µF (MFD): must be the same as the old one or the motor label.
  • Volts: same or higher. 440 V can replace 370 V.
  • No capacitor now? then the motor does not use one. Do not add one.

Safety first

Unplug the cooler, or turn off its breaker, before you open the motor cover. A capacitor can hold a charge even with the power off. Do not touch its terminals until it is discharged.

Discharge it with a capacitor discharge tool or a resistor rated for the job, with insulated handles. Water and electricity sit close together in an evaporative cooler: keep the motor and wires dry while you work. Not comfortable? Call a licensed technician.

1Condenser means capacitor here

Early capacitors were called condensers, and the old word is still used today. A "condenser for a cooler motor" is the run capacitor that helps the motor start and run.

Do not mix it up with an air conditioner condenser: that is the outdoor unit with the coil and fan. If you need the fan motor for an outdoor AC unit, see condenser fan motors.

2Does your motor use a capacitor?

Some single phase motors keep a run capacitor in the circuit all the time. Others start and run without one. Check before you buy:

  • Look for a small round or oval can wired to the motor or mounted near it.
  • Read the motor label. A motor that needs a capacitor often lists its µF and volts there.
  • No can and no µF rating? The motor does not use a capacitor. Adding one will not fix it.

3Match the µF exactly

Read the label on the old capacitor. µF is also written MFD or uF; they mean the same thing. The new one must have the same µF. The tolerance on the label, like ±5% or ±6%, is the normal range, not a choice of sizes. A bigger or smaller µF changes how the motor runs.

One motor uses a single run capacitor: one µF value and two terminals. A dual run capacitor has two values and three terminals and runs two motors in an AC unit, the compressor and the fan. Dual run vs single run.

4Volts: same or higher

The voltage on a capacitor is the most it is rated for. A 440 V capacitor can replace a 370 V one with the same µF. Never use a lower voltage than the old one. Can a 440 V capacitor replace a 370 V one?

5Size, mounting and wiring

  • Pick a shape and size that fits the bracket or strap, so the can is held firmly.
  • Take a photo of the wires before you remove the old one. Move them one at a time.
  • Match the terminals: most single run capacitors have two, with one or more tabs each.

Common single run sizes: 7.5 µF and 10 µF. Or browse all run and start capacitors.

Signs the capacitor is the problem

  • The motor hums but the fan does not turn.
  • The motor starts slowly, or only some of the time.
  • The capacitor top is swollen, or oil is leaking from it.

A capacitor can also fail and still look fine. A technician can test it with a meter that reads µF. A hum can also mean a seized motor or bearing, which a new capacitor will not fix.

Ready to match the numbers?

Filter by the specs printed on your old part.

Shop capacitorsSearch by model

Part numbers

Run and start capacitors by part number · Condenser fan motors by part number · All part numbers

Next guides

5 MINHow to find your AC model numberRead guide6 MINWhich capacitor do I need?Read guide