High amperage parallel power feeders phase wires run in separate conduits AAA-BBB-CCC-NNN??
High amperage parallel power feeders phase wires run in separate conduits AAA-BBB-CCC-NNN??
(OP)
A Contractor was to splice two 1000 Amp busways together. The busways are about 100 feet apart. He used conduit but put each phases conductors in a separate conduit. I'm aware of the NEC Handbook that says it's essential to run A-B-C-N in each conduit, but it doesn't really state it like this in the actual NEC. Is there a big problem here?






RE: High amperage parallel power feeders phase wires run in separate conduits AAA-BBB-CCC-NNN??
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RE: High amperage parallel power feeders phase wires run in separate conduits AAA-BBB-CCC-NNN??
I have seen this several times with much less current.
A 400 Amp switch destroyed by heat corrosion by a 200 Amp load.
I have seen the paint burned off of a buss-way with uneven current.
In the Canadian Code it is called "Magnetic Encirclement".
In the Canadian Code steps must be taken to mitigate the effects when the unbalance is greater than 200 Amps. Personally I think that that limit is a little high.
That is why single conductor cables are entered into panels through aluminum plates or non-conducting plates.
If the conduits are non-ferrous, there may still be issues with higher than needed reactive impedance and excess voltage drop.
Bill
--------------------
"Why not the best?"
Jimmy Carter
RE: High amperage parallel power feeders phase wires run in separate conduits AAA-BBB-CCC-NNN??
xnuke
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RE: High amperage parallel power feeders phase wires run in separate conduits AAA-BBB-CCC-NNN??
RE: High amperage parallel power feeders phase wires run in separate conduits AAA-BBB-CCC-NNN??
soonimmediately become obvious.If the conduits are non-ferrous it will be more an issue of inductive reactance and higher than expected voltage drops.
This rule will prohibit the installation in Canada:Is there a similar rule in the NEC?
Bill
--------------------
"Why not the best?"
Jimmy Carter
RE: High amperage parallel power feeders phase wires run in separate conduits AAA-BBB-CCC-NNN??
RE: High amperage parallel power feeders phase wires run in separate conduits AAA-BBB-CCC-NNN??
Bill
--------------------
"Why not the best?"
Jimmy Carter
RE: High amperage parallel power feeders phase wires run in separate conduits AAA-BBB-CCC-NNN??