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Electric Motors/Alpak Induction Motor


I would like to know if the following motor is suitable for a Variable Requence Drive
Frame Type - D365T
Serial # - TP551597 07

Gord,  I am finding nothing on this NEMA Frame ALPAK     it should be a standard NEMA 365T Frame, the suffix is nothing but a standard large shaft compared to a TS,  the motor compatibility with a drive should be noted on the nameplate,  even if it is included in the packaging docs,       

If not new,  you will have to try and chase down Alpak,  and see if they can cross the serial and find out if the motor was wound for VFD duty

TO be honest it is a crap shoot either way,   I have seen VFD approved motors fail on drives,  and non VFD motors operate just fine, on VFDS, the more modern the VFD   any brand the less likely you will experience problems,    but even on VFD labeled motors they are very specific about the compatibility, as far as the considerations I listed below,      

I cannot find the serial and any relationship with ALPAK      I have no idea if it is new, if it is  it should say somewhere on the data plate  stamped or permanent that the motor is suited for frequency drive use,        

Past that most motor shops can pull one end off and see if the windings are formed with freq duty wire   it is fairly easy to identify the wire just by the color,   

365 frame motor dependent on speed could be 50 to 75 HP    so no small gamble,     

But again the only way to know is some cross reference of the serial  from ALPAK     

If it came on or with a piece of driven equipment it could be the serial will be OEM to the manufacturer of the device, [compressor so on]  and then there will likely be no information   only if it is an off the shelf motor    and it appears it could be with the standard frame is there a good chance you can trace back by serial,       

Wish I could help more, but ALPAK doesn't provide a detailed listing by Serial that I can find,     

If you have any other info on the motor, history of the motor,  new used  new surplus   you might send that to me and I may be able to gather more information for you,      

I believe ALPAK through 200 IEC frames are all inverter duty,  but when you get up in these integral frames  it should be on the data plate,  if it has a clean data plate and there is no mention of inverter duty it is likely not.

However that does not mean it will not operate on a drive,  but it depends on what you are going to do with the drive,  lots of speed changes and speed ranges way off the sync speed  are more likely to have issues than if you just used the drive for soft start.

So if you want to risk it,  and again  even rated motors fail on inverters      there is just no absolute   only the warranty    that counts,        and then if it does fail    they have to do a warranty evaluation     

Anything else you can tell me is bound to be a help,     the motor at a 365 T   DEPENDING ONE THE BASE SPEED is may be a very typical 1800 off the shelf motor but without more infor it could be a 900 rpm that is very expensive and you would not want to chance it,     

Send me whatever else you have and I will help you from there          


Depending on the age of the motor,   and the type of drive and the considerations below:

Inverter compatibility with motors is complex. As a result, many variables
must be considered when determining the suitability of certain types of
motors. These variables include:
Torque requirements (Constant or Variable)
Speed Range
Line/System Voltage
Cable Length between VFD & Motor
Drive Switching (Carrier) Frequency Motor Construction
VFD dv/dt
High Temperatures High Humidity
Wider speed ranges, higher voltages, higher switching frequencies
and increased cable lengths all add to the severity of the application
and therefore the potential for premature motor failure. Nidec Motor
Corporation has differentiated its products into families for your ease of
selection for various inverter applications.

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Three phase/ AC DC single phase motors, controls, any problems or failures, motor installation, performance issues, connections. All other electric motors/gearboxes/apparatus. Specialty repair concerns, obsolete motors and solutions. Other mechanical or specialty equipment. See my profile under Home/electrical at this site


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