Exposed NM 6/3 and 10/3

[CharlieFer]

I’m working in a finished basement with floor joists overhead at 6’11”. I need to run both 6/3 and 10/3NM perpendicular to the joists, on the surface, and then bring it down to this wall on the left for 11 disconnects. I don’t believe I need to worry about the NM being subject to physical damage do I?

On the left wall I’m gonna install some plywood and create a box for my disconnects to be mounted on so that I can cover the romex coming down the wall, but suddenly I’m wondering if I’ll need to box the overhead romex as well. Thanks in advance.

 

[Little Bill]

You can run both exposed. However, the 6-3 NM can strap/staple straight to the bottom of the joists, the 10-3 would need to be either through bored holes, or placed on a running board.

 

[CharlieFer]

You can run both exposed. However, the 6-3 NM can strap/staple straight to the bottom of the joists, the 10-3 would need to be either through bored holes, or placed on a running board.

I see, what’s the reasoning for the 10-3 needing to be protected but not the 6-3? I think I’m gonna attach some 2x4’s and just box it out regardless, save myself the hassle

 

[Little Bill]

I see, what’s the reasoning for the 10-3 needing to be protected but not the 6-3? I think I’m gonna attach some 2x4’s and just box it out regardless, save myself the hassle

I think it's the size of the cable. Someone might try and use the cable for hanging things off of it. The larger cable could handle it, depending of what is hung there, but the smaller cable could be damaged.
This is just what I have been told. I don't know for sure if that is the official reasoning or not.

 

[jap]

I see, what’s the reasoning for the 10-3 needing to be protected but not the 6-3? I think I’m gonna attach some 2x4’s and just box it out regardless, save myself the hassle

That's a good idea.

Those rough sawn floor joists look perfect to me.

Jap>

 

[kwired]

I think I’m gonna attach some 2x4’s and just box it out regardles

For that reason I would tend to prefer to just run EMT most cases. You mention 11 disconnects are they being supplied by said cables or are the disconnects supplying the cables? That aspect could change how I might run things as well. I'd probably be running either common feeder and/or multiple branch circuits in raceway(s) if they all are routed through same path for a significant length.

 

[CharlieFer]

For that reason I would tend to prefer to just run EMT most cases. You mention 11 disconnects are they being supplied by said cables or are the disconnects supplying the cables? That aspect could change how I might run things as well. I'd probably be running either common feeder and/or multiple branch circuits in raceway(s) if they all are routed through same path for a significant length.

10 6/3’s are coming in to 10 disconnects, I forgot 1 is no longer going here. Piping would need to branch out to 10 boxes that are gonna be lined up 5 on top of 5, so just too complicated to pipe it. The 10/3’s are then going from each disconnect to a j box to feed each existing apartment that has MC. I may be able to pull back some MC to route it into the disconnect but in case I can’t 10/3 NM it is.

 

[kwired]

10 6/3’s are coming in to 10 disconnects, I forgot 1 is no longer going here. Piping would need to branch out to 10 boxes that are gonna be lined up 5 on top of 5, so just too complicated to pipe it. The 10/3’s are then going from each disconnect to a j box to feed each existing apartment that has MC. I may be able to pull back some MC to route it into the disconnect but in case I can’t 10/3 NM it is.

Not knowing much of what you have to deal with, it sounds like you need a larger feeder and a panelboard instead of all those disconnects.

 

[Elect117]

10 6/3’s are coming in to 10 disconnects, I forgot 1 is no longer going here. Piping would need to branch out to 10 boxes that are gonna be lined up 5 on top of 5, so just too complicated to pipe it. The 10/3’s are then going from each disconnect to a j box to feed each existing apartment that has MC. I may be able to pull back some MC to route it into the disconnect but in case I can’t 10/3 NM it is.

This doesn't sound code compliant to me.

6/3s down to 10/3s aluminum to feed apartments? Are they fused at 30A? Do you have more than one circuit supplying each dwelling unit? Or is this their one circuit?

 

[kwired]

Piping would need to branch out to 10 boxes that are gonna be lined up 5 on top of 5, so just too complicated to pipe it.

That's what wireways are for.

This doesn't sound code compliant to me.

6/3s down to 10/3s aluminum to feed apartments? Are they fused at 30A? Do you have more than one circuit supplying each dwelling unit? Or is this their one circuit?

Sounds like load is fairly minimal. Should do a load calculation from art 220 and probably can run a lesser expensive feeder than what it will cost for all those 6/3's. Maybe even as low as a 125, 150 or 200 amp feeder and supply a panelboard instead of all those disconnects.

 

[Little Bill]

This doesn't sound code compliant to me.

6/3s down to 10/3s aluminum to feed apartments? Are they fused at 30A? Do you have more than one circuit supplying each dwelling unit? Or is this their one circuit?

Where did you see the OP was using aluminum wire?

 

[CharlieFer]

This doesn't sound code compliant to me.

6/3s down to 10/3s aluminum to feed apartments? Are they fused at 30A? Do you have more than one circuit supplying each dwelling unit? Or is this their one circuit?

Old knob and tube, they were all ran off 30’s from when they were built back in the 1800’s. One circuit supplies the entirety of each apartment.

 

[CharlieFer]

That's what wireways are for.

Sounds like load is fairly minimal. Should do a load calculation from art 220 and probably can run a lesser expensive feeder than what it will cost for all those 6/3's. Maybe even as low as a 125, 150 or 200 amp feeder and supply a panelboard instead of all those disconnects.

This is purely to comply with the 60A minimum size service disconnect circuit breaker rule for each unit at the 11 meter MeterPak. 11 units with individual meters were already fed with 30A breakers and prior to that fuses, I have to install this in line simply to have a place to install a 30A breakers.

 

[CharlieFer]

Each unit isn’t even using 220V, just a single leg

 

[Eddie702]

When I ran perpendicular to the joists and didn't have anything for a running board I would staple it up and then come back and put guard strips on either side.

 

[kwired]

This is purely to comply with the 60A minimum size service disconnect circuit breaker rule for each unit at the 11 meter MeterPak. 11 units with individual meters were already fed with 30A breakers and prior to that fuses, I have to install this in line simply to have a place to install a 30A breakers.

I was thinking earlier about asking if these are separately metered somehow, now what you are doing does make some more sense.

That said, can you not install 30 amp breakers at the meter(s)? Most meter packs I seen will take anything up to 125 unless it is a 150+ amp tenant meter space.

There about has to be service disconnect ahead of 11 meters or you are in violation of six disconnect rule so the runs to each unit are feeders and there is no minimum size feeder to each unit other than per load calculations, but right or wrong you somewhat have already set that at 30 amps with the size of conductor you basically be extending.

 

[CharlieFer]

I was thinking earlier about asking if these are separately metered somehow, now what you are doing does make some more sense.

That said, can you not install 30 amp breakers at the meter(s)? Most meter packs I seen will take anything up to 125 unless it is a 150+ amp tenant meter space.

There about has to be service disconnect ahead of 11 meters or you are in violation of six disconnect rule so the runs to each unit are feeders and there is no minimum size feeder to each unit other than per load calculations, but right or wrong you somewhat have already set that at 30 amps with the size of conductor you basically be extending.

The meterpak takes 30A QO’s, but I think 230.79 or something similar is where the inspector is coming from. I didn’t feel like arguing with him as he’s pretty knowledgeable, seemed to be an electrical contractor in the past. There’s already a main fused disconnect for all 11 meters.

 

[Elect117]

Where did you see the OP was using aluminum wire?

I was reading section 230 before posting and the minimum wire size was #8 copper or #6 al. and that made it's way on the the forum post lol. I was thinking the OP was bringing down #6 service conductors as Al. But it was all assumptions. Nothing the OP said.

 

[Fred B]

I see, what’s the reasoning for the 10-3 needing to be protected but not the 6-3? I think I’m gonna attach some 2x4’s and just box it out regardless, save myself the hassle

Its not about protection its about support. You can run between the joists.

What are you building out? With 11 meters and such small panels sounds like are you building out a bunch of SRO's or extended stay hotel rooms? If so, that in most municipalities require metallic wiring methods (MC, EMT etc.) and NM is prohibited even PVC can be restricted.

I would personally use this made by Arlington, can mount between studs and carry the cables. These are made for NM, MC or EMT.

 

[AC\DC]

Are these runs service or feeders?