Large AC motor wiring
Large AC motor wiring
(OP)
For the project of automotive test facility we use a large AC dynamometer (1040 FLA).As per customer spec, this motor must be translating with significant amount of travel in both X and Y axes. To meet the spec, we have to use cattracs and flexible motor cables, and in this case we would need to use 10 cables in parallel, each cable (3 phase, 4 conductors, shielded) is VFD rated, Olflex/LAPP brand, conductor size AWG #2. These cables run from motor J-box through the cattrack and terminated at the end of the cattrack in fixed floor mounted enclosure. The problem is that NEC(2005 Edition) allows to connect conductors in parallel only for sizes AWG 1/0 and larger (exceptions listed in article 310.4 do not apply in our case). Any opinions how to handle this situation?





RE: Large AC motor wiring
RE: Large AC motor wiring
Is it the shielding requirement that is causing the problem?
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Sometimes I only open my mouth to swap feet...
RE: Large AC motor wiring
Welding cable is not permitted for use on power systems by the NEC...There is a Type W flexible power cable that is almost identical that is permitted for this use by the NEC.
Don
RE: Large AC motor wiring
thinker,
What you will likely need to do is to change to using a lower count of individual shielded conductors of a larger gauge. Lapp / Olflex makes it. 4 x 250kCMil per phase should probably do it.
http
RE: Large AC motor wiring
RE: Large AC motor wiring
RE: Large AC motor wiring
RE: Large AC motor wiring
respectfully
RE: Large AC motor wiring
thinker,
You might try scouring the depths of the odd-lot wire brokers for some short lengths. Houston Wire and cable is one http://www.houwire.com/ , Anixter is another http://www.anixter.com , but there are a lot of others out there.
Still, it seems as though the VFD manufacturer's engineers are living proof of my signature line...
JRaef.com
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