motor testing

[jcole]

Hello guys.

I sent a 3ph 60hp induction motor off for a checkup because the motor had smoked and water had entered it.

I recieved a call back and was told that it had failed a surge test and that it would have to be rewound and something about baking the motor. Before I approve the po can you answer these questions for me?

What is the purpose of a surge test and how does this show if the winding are good or not? Theory please.

What does he mean by baking the motor?

What is the process of rewinding a motor and what materials are used?

I asked these questions to the rep and he couldnt help, accept with a phone number.

Thanks for any replies.

 

[VinceS]

This may help...

This may help...

Follow this link...

http://www.reliabilityweb.com/art04/motor_pdm.htm

Surge testing is described in outline section "D"...

Baking the motor removes moisture from the windings.

 

[mdshunk]

If it failed the surge test, baking it will only mask a problem that continues to exist. Have it rewound or replace it.

 

[Besoeker]

If it failed the surge test, baking it will only mask a problem that continues to exist. Have it rewound or replace it.

The OP suggests that it will have to be rewound then baked.

 

[Cold Fusion]

If it failed the surge test, baking it will only mask a problem that continues to exist. Have it rewound or replace it.

Help me out. I don't understand what problems would be masked.

Say the repair shop bakes it out. It passes a surge test and megs out fine. What is being masked?

Or, after baking out, it fails either the surge test or meg. Repair shop says, "Rewind". Again what problem is being masked?

cf

 

[Cold Fusion]

(cut)it had failed a surge test and that it would have to be rewound and something about baking the motor.(cut) .

The "would have to be rewound" part is pretty clear. The repair shop says it is dead - no amount of baking or varnish is going to fix it.

The "something about baking the motor" part says you really should call the repair shop and talk to the foreman. I have never had any trouble getting a shop to tell me what they are going to do.

I would really hesitate to guess on the information in your OP.

The rest of your questions are pretty straight forward, but I still recomend you call the shop first.

cf

 

[mdshunk]

Help me out. I don't understand what problems would be masked.

Say the repair shop bakes it out. It passes a surge test and megs out fine. What is being masked?

The winding varnish would still be compromised, only there's no longer water bridging the gap, so to speak.

Or, after baking out, it fails either the surge test or meg. Repair shop says, "Rewind". Again what problem is being masked?

In that example, nothing.