WEG 5HP Dual Capacitor 208-230 volts single phase Motor Capacitors

Does anyone have a WEG 5HP Dual Capacitor 203-230 volts Single Phase Electric Motor in their shop?. I need the capacitor values. Model

0898 AP77935. The motor is usually found on a compressor.

I am trying to repair this motor for a shop and 3 electricians have given up. But the capacitors are missing. Yes missing. The wiring for the capacitors is not in parallel so the capacitors are probably for running and starting.

WEG is unable to find the model number in their reference materials. And the local motor shop is no help without the capacitor values.

Thanks for any assistance.

WEG is unable to find the model number in their reference materials. And the local motor shop is no help without the capacitor values.

I had an initial helpful reply to the above message and additional information was possibly available but things apparently got lost in the shuffle.

Thanks for any assistance.

Bob AZ

Reply to
Bob AZ
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A motor repair shop should be able to recommend and supply the correct values for the start and run capacitors this motor requires.

Make certain to mention that the motor is air compressor duty rated, and listen to hear the term capacitor-start/capacitor-run motor, which is the specific type of motor you have.. and if there's any suspicion that they don't know what you're referring to, call/visit a different shop.

A CS/CR air compressor duty rated motor of this size will typically require a start cap value of about 650-850uF and a run cap value of about 25-50uF (uF, MF, mF typically used to represent microfarads).

The caps need to be AC types (no polarity markings for +/-) and will typically be rated/marked at about 300VAC.

If you don't have a motor repair shop that you can call or visit, try a HVAC supplier such as Johnstone, where they at least have some experience with parts for these types of motors.

It's not that WEG would've used any special values of caps critical to this specific motor.. the cap values would be about the same for most other CS/CR motors of this size rated for air compressor duty.

Reply to
Wild_Bill

This a long shot but.............are there numbers on the compressor tank and does the motor look original? If so, go the compressor mfg and see if they can help you. Good luck Lyndell

Reply to
Lyndell Thompson

WB

I am inclined to take your advice and try capacitors in the sizes you suggest. If the starting and running current are close to the name plate I will let it go. If not I will adjust the sizes as needed.

There are some posts that suggest 80uf per HP for starting and 100 for running. Maybe I will call WEG again and hope to get some more information.

Thanks Bob AZ

Reply to
Bob AZ

As a manufacturer, they should have someone in the company that knows something about motors, and it wouldn't need to be a design engineer or someone who assembled this specific motor model.

If they have any specs of CS/CR capacitor-start, capacitor-run air compressor duty rated motors that are the same HP as yours (and approximately the same size pump), the cap values will be completely suitable.

One characteristic of motor cap values is they have a wide tolerance as far as value.. so if the marked value indicates 10uF, the actual measured value of a new cap may be as low as 7, high as 13, but most likely less than +/-

20%.

Heavy duty motors and power circuits in general aren't as critical of component values as electronic circuits are.

My local motor shop told me years ago that for *fractional HP* motors, the Start cap value ROT rule of thumb is 500uF per HP.

When the motor HP size is over 1 HP, the ratio drops because the values get huge.

The Run caps for motors that I've had apart are only a small fraction of the Start cap value, and in the last 3 HP CS/CR air compressor motor I serviced, the Run cap value was about 20-30uF, IIRC.

FWIW, For small CR AC motors such as PSC permanent split capacitor types used in gearmotors and various machine applications (up to about 1/8 HP), the cap value will slightly affect the motor's speed (and operating temp), but the cap values are often single-digit values, and most often less than 20uF.

Reply to
Wild_Bill

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