60Hz and VFD Feeder in same conduit
60Hz and VFD Feeder in same conduit
(OP)
Does anyone know of a reason why I cannot run a 480V 3 Phase 60Hz feeder (to an AC unit) in the same conduit as a 480V 3 phase feeder from a VFD (to a Fan)? Are there any code reasons why this should not be done, or any magnetic interference reasons, practicaly reasons, etc..?
Thanks,
Thanks,






RE: 60Hz and VFD Feeder in same conduit
Since the other circuit is a 480V power circuit, you might not have too many problems, but some of this hash could get coupled into the A/C unit's low voltage circuitry and cause problems.
The only Code restriction would probably be the need to derate the ampacity of both circuits due to more than three current-carrying conductors in the same conduit.
RE: 60Hz and VFD Feeder in same conduit
Gunnar Englund
www.gke.org
RE: 60Hz and VFD Feeder in same conduit
RE: 60Hz and VFD Feeder in same conduit
"Our virtues and our failings are inseparable, like force and matter. When they separate, man is no more." Nikola Tesla
Member, P3
hrc (Electrical)
I've done that...put VFD's in the same panel as regular starters BUT...like all control signals, etc I followed the best practices. Ran the signals away from the normal high power stuff, crossed at 90 degree (helps prevent cross coupling) and used shielded cables.
dpc (Electrical)
Metal-clad cable, such as Okonite C-L-X is a good option for VFD output circuits. It now comes standard with three separate interstitial ground wires.
jraef (Electrical)
Yes, that is the best solution when physical separation is unavoidable. Several MCC manufacturers mention that in newer installation giudes as well.
Read the Eng-Tips Site Policies at FAQ731-376
RE: 60Hz and VFD Feeder in same conduit
So alot comes down to just how well you build it. And how well it gets installed.
RE: 60Hz and VFD Feeder in same conduit
RE: 60Hz and VFD Feeder in same conduit
"Our virtues and our failings are inseparable, like force and matter. When they separate, man is no more." Nikola Tesla
Member, P3
Read the Eng-Tips Site Policies at FAQ731-376
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