STATOR COIL CLAIM 1

[petronila]

Good day,

I would like to know what do you think about this case history:

Last Year, some stator coil manufacturer was made 120 coils in order to repair a 600 HP-4160 Volts electric motor,the coils was ordered by a stator form wound coil form ,but the data was not taken from the stator´s winding, the coil´s data was provided from the original manufacturers drawings.(50 years old but trully)Finally the coils was manufactured and stored waitting for the schedule maintenance stop. When the factory was ready, the stator was sended to rewound but the coils don´t match.

The real sizes taked from the stator shows a mistake in the INTERNAL DIAMETER SIZE,because the person who filled the form have a mistake, for it the coil manufacturer was made coils with wrong chord size.

This situation was informed to the coil manufacturer, the answer was sorry but we fed a program with the INTERNAL DIAMETER SIZE AND THE SLOTS NUMBER and we have the chord calculation. The question is : IF THE COSTUMER IS PROVIDING THE CHORD SIZE WHY THE COIL MANUFACTURER DON´T CHECKED THE PROGRAMS SIZES WITH THE PROVIDED? Did you think the coil manufacturer has some responsability in this case??

Thanks for the inputs.

Petronila.

 

[edison123]

MV motors are custom designed and built. Unless the coil supplier had physically checked the machine parameters (like core length, dia, slot size etc.), they cannot know them. That is why a coil data sheet is required to be filled by the client for coil manufacture. If they made the coils as per the data provided by the customer, they are not at fault.

* If a little knowledge is dangerous, then I am the safest person in the world *

 

[Skogsgurra]

You say that "the coil´s data was provided from the original manufacturers drawings".

Does that mean that your specification was just that? In that case it is obvious that the coil maker has made a mistake. But, on the other hand,if you gave him the machine data and that is what he is used to and always uses, I can understand him. A third situation is if you gave him coil data and he asked for motor data, ignoring coil data.

The coil winder should have used your coil data. But then he probably could not (or did not want to) enter them into the coil machine. So he took motor data instead. I think that he should have checked the resultant settings against your coil data.

Also, when the coils were received, I think that QC should have had a look at them to confirm that they were the right size.

I would say that the responsability is more with the coil winder than with the buyer. But there are shades of grey there.

Gunnar Englund

http://www.gke.org

 

[electricpete]

I tend to agree with edison. If he built what you asked for on paper, it's tough to hold him legally accountable. Although perhaps if he were on his toes there might be some way he could have caught the mistake in your specification/ / purchasing documents ?

Just to clarify:

"the coil´s data was provided from the original manufacturers drawings"

"the person who filled the form have a mistake.."

If I read this right, the original motor manufacturer's drawings were correct, and the data was incorrectly transposed from that motor manufactuer's drawing onto a purchasing document by someone in your organization, correct?

Were the OEM drawings ever provided to the coil manufacturer?

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[Davercn]

I understand that the customer did not measure the old stators but had the original drawings. The data sheet was developed using the original drawings and the correct core diameter of the motor was not written on the data sheet. Instead the wrong core diameter was given to the coil manufacturer on the data sheet.
First, the motor is 50 years old. Any coil manufacturer that has been in business for a respectable length of time, as my company has, would have wound this motor coil before. The problem would have been discovered after the first sample coil was wound, or even before. The customer would have been called to check his data and the problem would never have gotten this far.
However, considering that the manufacturer built the coils to the specs provided the hard reality is - the customer received what they ordered and is responsible. The manufacturer, however, in order to keep a customer would negotiate a reduced price for rework or manufacture of new coils.

 

[aolalde]

Hi Petronila.

Since "the person who filled the form have a mistake, for it the coil manufacturer was made coils with wrong chord size." The responsible is the person or company that filled the wrong data.

As Edison mentioned OEM's motor designs, even for the very same HP, Speed and Frame could be different. therefore the coil manufacturer does not have a way to ensure if the data received with an order is correct or not.

 

[powerjunx]

Hi Petronila,

Even we experinced rewinding over a decade or more, it is better to counter check such data collection especially to critical specifications.

When we do the rewinding, we do require the coil manufacturer to send a representative to check whether their coil design is perfect, in contrast to existing one, before affirming their PO checks. Rewinding such unit is no joke interms of repair cost and we cant afford to have a back job.

In your case, it is highly probable that the OEM will never garantee your claim.

Next time, it is better to have a good coordination on both party for this crucial orders.

 

[oftenlost]

This post confuses me a little. (easily done) Even a 50 year old motor core stays the same physically. If the manufacturer's data provided to the coil shop was correct and the coil shop recorded the wrong data, they should be responsible. If the error in recording was the OEM, good luck getting relief.