Motor Valid Data

[Modula2]

I find that at least one motor manufacturer allows their marketing staff access to motor performance data for manipulation, recalculation, etc. At design stage, we get sloppy spreadsheet submittals, obviously assembled by sales staff. Some data is obviously calculated by sales persons, and usually inconsistent or incomplete data. A long time after the motor is bought by others, and our asking for valid engineering data, we receive a more complete document, which is easy to do today with office software. On examination, it is obvious this is also assembled by the sales dept. Are there now manufacturers who no longer have engineering dept. originated and controlled data?

 

[electricpete]

I'm curious what kind of design data you are talking about and whether this would be a catalog motor or special order.

 

[jbartos]

Suggestion: It appears the original posting touched base pertaining to manufacturer product information and application. I share my experience with something similar. The prestigious manufacturer of protective relays provided information about auxiliary contact relay rating within email to me. I checked posted documents on the manufacturer website and I noticed discrepancy. The posted document indicated the higher current rating for the auxiliary contact. I sent the email to the tech support, left messages on the answering machine (always on) and I never received any information explaining the discrepancy. I now try to concentrate on a good contact or connection with the tech support, meaning telephone calls, and discussion first, if possible. Then, fax or email communications. Sometimes, this is not possible since only the email is known. Some manufacturers, often overseas, do not respond my emails pertaining to more information about the product, mainly literature.

 

[mdonner]

Hi there

I am somewhat confused: you get garbage for engineering data and yet purchase the "goods"?!
If you can not reach tech contacts, what will happen if you need warranty service and support?
How about local rep/distributor to assist you with the required info?
I used to work for a local rep of Reliance Electric (now Rockwell), and customers received full engineering data and support. I believe there are many others that will offer the same service: do not compromise.

 

[Modula2]

When a mechanical engineer buys the motor as part of the equipment package and ignores the EE input, then, yes, the EE has the garbage to live with, such as excessive flicker, poor torque (long start) and so on.

In the end, the data was completely supplied, but not certified datasheets from the engineering dept., unaltered by anyone else, but rather assembled by the sales person using a wordprocessor and spreadsheet. You want valid data, then they simply add a "validated or verified by" box and enter the salespersons initials.

The point is that when a manufacturer provides it's engineering data to the sales and reps and allows them to extract, modify, reformat and so on, then how do we have confidence in it. For example, you want 50% torque, current vs speed curve and it's not available, then the salesperson simply calculates and presents it the same as original data from the engineering dept.

This is not one of your good two companies, who do properly control data and it's integrity. But it is one of similar stature. This can be turned around to make valid data a selling issue.

 

[Farkel]

Certified Testing other than routine tests is expensive, and one can ask for these to vertify engineering data,and with witness tests if needed. Historically nameplate data of motors has been only an indication of what is really is, so one has to dig much deeper if one is concerned with performance. Case in point, many manufacturer's of motors nameplate motors with a given horsepower; however, when one does the calculations of HP=Slip Speed x Torque / 5250, one does not come up with that figure on the nameplate.

 

[Modula2]

Certified testing is not always needed. Engineering calculated data is sometimes all that is available and that has become more accurate today with 3D electromagnetic and other software. This is more extensive than nameplate data, with full torque and current vs speed curves, and so on. That data must be signed and fixed by the design dept. and not modified or re-calculated by the sales dept. It's a question of proper data control to ensure validity.

 

[jbartos]

Suggestion: I was reviewing a 1MW generator damage curve by Newage. There was a fine print to the extent that the curve is for information and also serves as an input for protective and coordination study. There were no guarantees that the curve accurate. This necessitated a comment regarding a tolerance band for the damage curve or the lower safe limit of the damage curve, which would be the lower boundary of the damage curve.