BX / armored cable vs EMT connection

[solardad]

Redoing my setup and got a 6x6 36” wireway to help clean up the connections to my sol-ark 12k.
Thinking about reusing the original BX cable sheathing from the wireway to the inverter vs. buying EMT.

Was searching the nec 2020 code and did not come across any call outs in not using BX but I thought I would ask the group in case I missed it.

Thanks

 

[timselectric]

I assume that you are referring to MC cable.
That's perfectly fine. But EMT is better for protection and looks.

 

[zanydroid]

Annotated picture of your setup would help a lot.

You can use MC and FMC but NEC has quite prescriptive protection requirements. Which you can get around by using larger trade sizes but you are reusing. Depending on the EMT run involved it might be easier to bend EMT even with messing up a few times.

 

[solardad]

I assume that you are referring to MC cable.
That's perfectly fine. But EMT is better for protection and looks.

Correct. Thanks for the info.

 

[zanydroid]

Also after adding all the guard strips for your presumably undersized MC (since the minimum size excluded from those requirements is larger than what you need for conduit fill/used in MC cable for the kind of conductors you are likely using).

If running exposed in a place you care about It will look even worse compared to EMT.

 

[solardad]

Annotated picture of your setup would help a lot.

You can use MC and FMC but NEC has quite prescriptive protection requirements. Which you can get around by using larger trade sizes but you are reusing. Depending on the EMT run involved it might be easier to bend EMT even with messing up a few times.

Distance of run is only 10”

Have 1” so there is no jam scenario per online calc., max wires for one connection is 6AWG x 4

 

[timselectric]

1" ?
Now, I believe that you are referring to FMC (Flexible Metal Conduit).

 

[zanydroid]

You are in luck. It's big enough to dodge the nanny state

690.31 D


(2) Flexible Wiring Methods. Where flexible metal conduit (FMC) smaller than metric designator 21 (trade size ¾) or Type MC cable smaller than 25 mm (1 in.) in diameter containing PV power circuit conductors is installed across ceilings or floor joists, the raceway or cable shall be protected by substantial guard strips that are at least as high as the raceway or cable. Where run exposed, other than within 1.8 m (6 ft) of their connection to equipment, these wiring methods shall closely follow the building surface or be protected from physical damage by an approved means.

 

[solardad]

1" ?
Now, I believe that you are referring to FMC (Flexible Metal Conduit).

Correct. I’ve always referred to it as BX / Bronx aka FMC but I live in the past and default to BX

 

[zanydroid]

It's big enough to dodge the nanny state

To clarify I do believe in the extra paranoia since 500V and DC arc faults seem to merit some extra diligence

 

[timselectric]

To clarify I do believe in the extra paranoia since 500V and DC arc faults seem to merit some extra diligence

I also believe that the guarding requirement is necessary for small cables running across joists in an attic. It is very easy for a contractor (electrician or otherwise) to step on and smash it. Or break it over the edge of the joists.

But ,if I understood the situation we are discussing.
This is just a 10" vertical conduit between the trough and Sol-Ark. So, that rule wouldn't apply here.

 

[zanydroid]

But ,if I understood the situation we are discussing.
This is just a 10" vertical conduit between the trough and Sol-Ark. So, that rule wouldn't apply here.

Good point, the x" to equipment allowance applies and might be carte blanche.

 

[solardad]

I also believe that the guarding requirement is necessary for small cables running across joists in an attic. It is very easy for a contractor (electrician or otherwise) to step on and smash it. Or break it over the edge of the joists.

But ,if I understood the situation we are discussing.
This is just a 10" vertical conduit between the trough and Sol-Ark. So, that rule wouldn't apply here.

Correct, they would be vertical.

Thanks @timselectric and @zanydroid