GE 1000 HP DC Motor Field Coil Rewind 1

[jktwn]

A couple of days ago we had a failure of a GE 1000 hp extruder motor on one of our films lines here in our plant. The motor had a lot of water and ice ingested into the air intake from the roof during the snow storm shorting out 2 of the 6 motor field windings.

The motor shop says the repairs will take a few weeks mainly because of the fact that the motor has pole face windings and the repairs are labor intensive. I was wondering if anyone has experience with pole face winding repairs and if there might be a way to speed up the process. I don't think the shop is sandbagging on this one but I would like to make sure anyway. I have been told that getting the coils from GE will take 4 to 6 months. I don't have a contact at GE so I can't confirm this right away.
We have installed an 800 hp motor and will run it until the 1000 hp motor gets back from the shop. The main problem with this is we may have to derate production output on some products with the smaller motor in place.

Thanks

Wayne

 

[Skogsgurra]

The pole face windings are compensation windings. They are there to make the armature current/torque relationship linear over a larger range.

It may be possible to run without them. Especially if your motor is fed from a controlled rectifier. You may not be able to run overload, but fairly close to full load would be possible.

Gunnar Englund

http://www.gke.org

--------------------------------------
100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...

 

[stardelta]

There is no hiding the fact, bar-wound pole-face compensation windings are very labour intensive to replace and there are no short cuts other than to work around the clock. Without seeing the job its difficult to give an estimate but assuming its a full field rewind shunt/series/comp`/interpoles 14 days is not at all unrealistic. I can understand your urgency, I hear it constantly. The first question we are always asked is when will it be back? often before we have even seen the motor let alone asessed its condition etc. I am sure that as a valued client they will be doing everything they can to return your motor as soon as they possibly can.

 

[edison123]

As a rewinder, I would say 3-4 weeks for the full field and the compensating windings. The sad part is that for a field rewind, even healthy compensating winding has to be rewound.

 

[jktwn]

Good feedback.

Looks like the motor is down for the count. We do have another 1000HP GE motor at another site in USA that is available but I'm not certain if it will fit. It is a frame size CD6270 versus CD6766 that came out. Electrical specs are similar althoght rpm is 1600 versus 1200.

Does anyone have a good source for large dc motor frame size information? I need some dimensions.

thanks again

 

[waross]

Should the 1600 be 1800?
remember that going from 1200 to 1800 will result in a drop in torque of 1200/1800. That's a 1/3 drop in torque. If this is direct drive you have a problem. If this is belt drive you may have to locate a different belt pulley. If space is limited you may need a different set of belt also.
respectfully

 

[unclesyd]

This pdf shows renewal parts for GE frame CD6766 motors. It might pay to give them a call.

page 28

http://www.secrist.net/acdc_mo_7_medium_dc.pdf