CH Ampgard MV Control & 4160 V 450HP motor burnout

[naminorite]

Here are the stats:

CH Ampgard MV Control Nameplate Data
Starter Type: Solid State RV/Induction
Rated Voltage: 4160V, 3-PH
Rated Load: 450HP, SF 1.0
Dwg Ref: ASMV0CP9S01, Mfg Date: 05/06

US Motors Titan II Nameplate Data
FR 5008P, Type RU, Encl WPI
Ph 3, 50 degree C, ID# M 12 20082021-0001 R 0001
Insul Class F
HP 450, RPM 1770, SF 1.15
Volts 4160, Max kVAR 75.3, NEMA Nom Effic. 93.6
Amps 56, Code 6, DES B
SF Amps 64, PF 89.6, Guaranteed Effic 92.4
Special Features:
175% EHT
Over Temp Prot 2

The distance between the VFD & the motor is over 1000 feet.

Suggestions on why the motor is burning out? Sorry so vague, I don't have a lot of history on this.

 

[rbulsara]

You described the nameplate not the problem or circumstances.
What is the issue? Burning out but under what circumstances?

Motor burn out from a variety of reason, start eliminating them one by one, until you narrow down to more probable ones. Start with overload, lack of cooling, under voltage (causing over current), voltage imbalance, insulation failure, poor maintenance, sabotage, excessive harmonics....list goes on.

Operating on VFD at low speeds will reduce cooling effect. There is a limit as to how slow you can run continuously on a VFD.

Get some experienced person on site or send it to a good repair shop and they may be able to shed some light on by looking at the motor damage itself.



Rafiq Bulsara

http://www.srengineersct.com

 

[naminorite]

The only additional info that I have to shed light on this is that it is not a cooling issue. There are two other motors that have the same setup and we are finding that they need to be replaced also. Interestingly enough, an older Westinghouse FV starter with the same type of motor has been the steadfast workhorse.

 

[rbulsara]

What is the finding that tells you to replace? You cannot hide the hat and ask for the donation at the same time.

Rafiq Bulsara

http://www.srengineersct.com

 

[naminorite]

I'm sorry for the poor choice of words. There are no "findings". It has just been from what I hear that in the past, the 3 motors on the VFDs have been replaced while the one of the FV starter has been working fine. I jumped into this without enough information for anyone to provide a clear-cut recommendation. I believe I should find out more info on what caused the 3 motors to be replaced and not assume that since the motor on the FV starter is working fine that it has something to do with the VFD.

 

[jraef]

Those are not VFDs, they are Solid State Soft Starters.

One common cause of motor failure when controlled by soft starters is improper setup / commissioning. Often times people ascribe capabilities to soft starters without truly understanding how they work and what they do. So they end up trying to make them do something that they cannot do, and it can be the motor that suffers the consequences.

For example, I have seen several instances where a salesman, in his zeal, allows a customer to believe they can start a motor with less than 100% FLA using a soft starter. Why? Because the soft starter programming will allow such a setting! Nobody explained to the user (or the salesman) that this was an impossible task, so they bypassed the overload protection and repeatedly attempted it until the motor suffered thermal damage. I'm not suggesting this is your problem, this is only an example to show that there are a lot of things it might be.

So in order to get help, you would need to provide a LOT more information.


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