mstrlucky74
Senior Member
- Location
- NJ
Have a spec that reads all vfd OUTPUT circuits to be inXHHW. Would the output wires be the wires from the panel to the vfd withintegral disconnect or from the vfd/disconnect to the motor? Thanks.
VFD Output Circuits XHHW
- Thread starter mstrlucky74
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- Placerville, CA, USA
- Occupation
- Retired PV System Designer
Anything connected to the VFD output. (On either side of disconnect.)
The main reason is the presence of high, sharp edged, voltage pulses which can stress the insulation in ways that a sine wave of the same nominal voltage will not.
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The main reason is the presence of high, sharp edged, voltage pulses which can stress the insulation in ways that a sine wave of the same nominal voltage will not.
Sent from my XT1585 using Tapatalk
mstrlucky74
Senior Member
- Location
- NJ
So that could or would be the wires on the line AND load side of the vfd/disconnect? So essentially the entire run.
I suppose so but I've only ever seen the problem with motors.
No, the output wiring would only be the wiring from the VFD to the motor.
mstrlucky74
Senior Member
- Location
- NJ
Thanks.
- Location
- San Francisco Bay Area, CA, USA
- Occupation
- Electrical Engineer
I think what GoldDigger was meaning is that if you have a disconnect on the LOAD side, i.e. within sight of the motor, you still need the XHHW. All the way from the drive to the motor as steve66 said.
Nothing special on the input side, other than the different sizing rule in 430.122.
mstrlucky74
Senior Member
- Location
- NJ
Thanks.
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