Its 415volts 3phase 18.5kw 8pole

Dear,

As long as no load current is < 30-40% of rated current, it is ok.

for 18.5 kw motor, Irated = 29.5 Amp.

12 Amp is 40% of rated current.

It is just acceptable, even though may not be that efficient.

Yes but as it is a 8pole motor dont you think the no load current should be a bit higer? Please advice. Thanks

Seems to be OK as per experience, however no data to authenticate.

best authentication may be from supplier.

Thank You.

Motor is working fine on load too.

Given that more poles means a slower motor and typically more inductance, What you have I would consider acceptable.

If the winding configuration or layout was changed from the original design its likely the inductance and no load currents are going to be different than what was original.

It sounds about right. I expect about 7A for an 11kW which translates to 11.77A for an 18.5kW.

You rewound the motor, did you change the bearings?

Look at #6 - It is working fine, so may be no problem. But as a precaution yes, he should have changed it. may be on next maintenance he will do it .

But since it is a low RPM machine, he should better go for power factor compensation, his pf is likely to be a bit low.

Exactly my point! One of the major problems with these open questions NO ONE gives enough info, so you have to ask a cart load of questions to find out how they got to where they're at! And why on the next maint schedule would you remove this particular motor, strip it down to change the bearings, when on a rewind you have the bloody thing apart in the first place, unless someone has worked out how to rewind without taking a motor apart. Why make work, be logical and proactive in these things

Thank You. Yes the bearings were changed. The motor is working well.

Thats good news, then I think you have all the answers you need from the other replies

Have you checked the power factor of the motor at various percentage loads before and after the change? I presume the power factor would have fallen in an eight pole design.

40% is ok.Best way is to check with manufacturers test report if u have one.