480V Switchgears

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rey-man

Senior Member
Location
New york
We need to feed a MCC with parallel feeders from an existing switchgear. The switchgear is on the 1st level. The new MCC is on a higher floor.

The plan is to run conduit from below the switchgear and route to the MCC. However, we cannot core-drill through the slab where the switchgear is on, no space in the gear for a coredrill machine.

there is one spare conduit sleeve that we can use for one feeder and its right on the section where the breaker we want to use is located. the other available sleeve is in the adjacent section.

Is it allowed by Code to cut a hole between sections to run the other set of feeder wires from a section to another section?

Is there an exception to run the other set from above the MCC?

As usual, Thanks for comments and info.
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
That would change the lengths and physical characteristics of the parallel sets, probably creating a violation of 310.10(H).
 

infinity

Moderator
Staff member
Location
New Jersey
Occupation
Journeyman Electrician
there is one spare conduit sleeve that we can use for one feeder and its right on the section where the breaker we want to use is located. the other available sleeve is in the adjacent section.

Is it allowed by Code to cut a hole between sections to run the other set of feeder wires from a section to another section?

Is there an exception to run the other set from above the MCC?

IMO no you cannot do this.

How thick is the deck with the sleeve in it? Is it possible to put a box directly under the sleeve location and install all of the conductors in one raceway? If 24" or less you can use 60% fill and no derating required.
 

rey-man

Senior Member
Location
New york
IMO no you cannot do this.

How thick is the deck with the sleeve in it? Is it possible to put a box directly under the sleeve location and install all of the conductors in one raceway? If 24" or less you can use 60% fill and no derating required.

the deck is only 18" thick but no way to put a box underneath. is there a reference for your recommendation? I'd like to note it down for future work.
 

petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
the deck is only 18" thick but no way to put a box underneath. is there a reference for your recommendation? I'd like to note it down for future work.

310.15 (B)(3) Adjustment Factors.
(a)(2)Adjustment factors shall not apply to conductors
in raceways having a length not exceeding
600 mm (24 in.).

Does your switchgear not have a wiring compartment across the top or the bottom where you could route the wires to get to the conduits? I don't use a lot of switchgear but i seem to recall the wiring compartments are open to the bus area and maybe you can run the wires through the wiring compartments and up the back side to where the conduits are.
 
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