AC motor wiring and capacitor use

[Trance]

Hello,

I'm totally a newbie to this but I'd like to get my problem fixed.

I have a chilling system made back in the '90 and the motor kind of
died (rotating slowly but never going to full speed). Someone in my
department has a similar system made by same manuf. that died for
different reasons, so I thought I could swap motors.

The problem is (1) I'm not sure about the wiring and (2) the rating is
different.

These are three wire motors (hence based on what I quickly read means
there are two coils, a starter one and a running one, the starter one
giving more torque). On both motors, two wires run together, and
another one is independent. Colors do not match, and even if they
matched, I would still like to properly wire based on knowing what the
wires do.

Another issue is that the rating is different. The motor that died is
rated for 16 microF, and I'm trying to replace it with a 8 microF one.
I'm not sure if this means some capacitor may need to be changed
accordingly.

Any suggestions would help. Thanks.

 

[Tom Biasi]

Hello,

I'm totally a newbie to this but I'd like to get my problem fixed.

I have a chilling system made back in the '90 and the motor kind of
died (rotating slowly but never going to full speed). Someone in my
department has a similar system made by same manuf. that died for
different reasons, so I thought I could swap motors.

The problem is (1) I'm not sure about the wiring and (2) the rating is
different.

These are three wire motors (hence based on what I quickly read means
there are two coils, a starter one and a running one, the starter one
giving more torque). On both motors, two wires run together, and
another one is independent. Colors do not match, and even if they
matched, I would still like to properly wire based on knowing what the
wires do.

Another issue is that the rating is different. The motor that died is
rated for 16 microF, and I'm trying to replace it with a 8 microF one.
I'm not sure if this means some capacitor may need to be changed
accordingly.

Any suggestions would help. Thanks.

You have two different motors.
I would suggest that you try a new capacitors on your original motor.
To adapt the other motor for your use would require some more specs.
Rated HP, torque, RPM, direction, mounting considerations just to name a
few.

 

[Trance]

In the post above I was wrong. I'm replacing a motor with rating of 8
muF with one with rating of 16 muF. The old motor most likely has one
of the coils fried so I cannot reuse it.

 

[Tom Biasi]

In the post above I was wrong. I'm replacing a motor with rating of 8
muF with one with rating of 16 muF. The old motor most likely has one
of the coils fried so I cannot reuse it.

The capacitor value is not the motor rating.
You say "most likely" has a bad winding, but do you know that?
A capacitor is a cheap test.

Tom

 

[[email protected]]

In the post above I was wrong. I'm replacing a motor with rating of 8
muF with one with rating of 16 muF. The old motor most likely has one
of the coils fried so I cannot reuse it.

There are both starting and run capacitors on some ac motors.
Presuming the motor is the physically similar to the one that burned
out why don't you just grab the capacitor from the other unit as well?

What does the motor do? Turn a fan?

 

[Baron]

There are both starting and run capacitors on some ac motors.
Presuming the motor is the physically similar to the one that burned
out why don't you just grab the capacitor from the other unit as well?

What does the motor do? Turn a fan?

I would be guessing, but I suspect that he is talking about the
compressor motor. In which case he is on a hiding to nothing !