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Motor nameplate data and drive question

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sproles43

Mechanical
Aug 2, 2006
1
I recently received a motor with nameplate in two parts.

Part 1:
Interter data
20 HP
6-60 HZ
460 V
23.6 Amps
1.0 service factor

Part 2
Sine Data
25 HP
60 HZ
460 Hz
29.7 Amps
1.15 service factor

The motor will be installed using a standard combination started (60 Hz) not a VFD.

Question 1 - Should the conduit, wire, starter, fuses, etc. be sized for per the NEC based on the 25 HP motor?

Question 2 - Is it a code requirements that if a drive is being installed on a piece of equipment with a standard motor (motor not rated by inverter service) that motor be replaced with a motor that is rated for inverter service?


 
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To install the motor for use on utility power, I believe you need to size per NEC based on the 25 HP nameplate marking.

NEC does not require the use of a motor rated for inverter service when connecting the motor to a VFD. If the motor needs to be UL listed, such as for use in a hazardous (classified) location, I believe that the UL label will be valid only for a motor that is rated for inverter service.
 
That's right. I also think that what that nameplate is saying is that it is an inverter rated motor, but not at 25HP. Instead they are saying that as an inverter motor it is only rated for a 20HP load.

http:/Eng-Tips: Help for your job, not for your homework Read faq731-376 [pirate]
 
Use:
Inverter Data when used with VFD.
Sine Data when connected to the utility or fix frequency source.
 
The derate on the inverter is probably due to a constant torque requirement over 6-60hz. It's probably good for 25hp variable torque 6-60hz or 25hp constant torque 15-60hz. Reliance often rates and labels their motors that way.
 
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