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Is this arrangement acceptable from NEC point of view?

Is this arrangement acceptable from NEC point of view?

Is this arrangement acceptable from NEC point of view?

(OP)


Please see attached scan:
https://res.cloudinary.com/engineering-com/image/upload/v1437659196/tips/Scan_xnx3b2.pdf

A quick summary:

Existing Design - MV Starter feeds a 500hp motor via undeground conduit.
Proposed Design - Use the MV starter to feed a MV VFD, and then re-use the underground conduit to feed the motor.

I'm curious to know if it is acceptable to route the cable between the VFD and motor via the MV starter section. We've made sure that there is sufficient space, cutout sections at the top, and no interferences.

The cable would be routed through the starter section inside a conduit, as shown in the attached photo.

RE: Is this arrangement acceptable from NEC point of view?

Where is the lockout for this motor, it is not shown in the your drawing. Also why have starter and a VFD in series? Remove the starter from system and go only with the VFD.
good luck,
Dave

RE: Is this arrangement acceptable from NEC point of view?

(OP)
The lockout will be on the VFD.

I don't have another supply available hence using the starter and vfd in series.

RE: Is this arrangement acceptable from NEC point of view?

I don't understrand... are you WIRING the starter in series with the VFD? Most MV VFDs need to have a controller / controlled breaker ahead of them anyway, so I don't see the problem. Nut if you are using the starter ENCLOSURE just as a raceway for the FEEDER circuit to the VFD, that might be a problem.


"You measure the size of the accomplishment by the obstacles you had to overcome to reach your goals" -- Booker T. Washington

RE: Is this arrangement acceptable from NEC point of view?

I am reasonably sure you could run the motor cable through the starter, but am not sure that you can run the conduit though the stater.
However I can't think of a code rule that says you can't run the conduit through the starter.

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