Calling all NEC Electrical and DIY Experts. Follow Up: Thanks Everyone.

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Sandtrap
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Calling all NEC Electrical and DIY Experts. Follow Up: Thanks Everyone.

Post by Sandtrap »

I'm doing the subpanel, feed, and electrical work on a new "shop/farm building".
The building is metal so "Code" is commercial style with EMT and MC cabling, steel j boxes, etc.

*Building permit has been run and permitted.

Question:
The feed to the panel is a 1-1/2" plastic conduit. It's in the rear corner of the shop and is 52 inches tall.
Since it is exposed and not against the wall, does it need to have a "chase" or other protection?

If so, would the following work to fit Code:

1. Full chase, boxing in or wall in (metal or wood studs w/half height wall?)
2. Unistrut on both sides, or just behind with a "U" clamp?
3. ????

I looked up the "NEC Code" but couldn't find something addressing this.
*note: I may or may not do an interior finish out flush to the "C" channels so has to look good.
Thanks for the help.
j :happy

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FOLLOW UP ADDED: (thanks everyone for your help)

Per code and everyone's advice, I added some unistrut to conform to the 36" rule for clamping feed conduit. I also added a 2 inch EMT section of pipe to the existing elec. PVC section to give it ridigity and protection. It had the right inside diameter to make it work. I was trying not to make things look too "jimmy rigged" but it was the best I could come up with.
Thanks again.
Image

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All that's left is to pull the main feed and land it.

j :D
Last edited by Sandtrap on Sat Sep 12, 2020 9:01 am, edited 5 times in total.
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gmc4h232
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Re: Calling all NEC Electrical and DIY Experts. Help?

Post by gmc4h232 »

Did you get a permit for this work? If so, just call the inspector and ask. If not, who cares if it meets code?

I doubt this is an issue in this application.
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Re: Calling all NEC Electrical and DIY Experts. Help?

Post by Sandtrap »

gmc4h232 wrote: Thu Aug 20, 2020 7:02 pm Did you get a permit for this work? If so, just call the inspector and ask. If not, who cares if it meets code?

I doubt this is an issue in this application.
Yes. Building permit issued. Good idea.
j :happy
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Chuck107
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Re: Calling all NEC Electrical and DIY Experts. Help?

Post by Chuck107 »

.....
Last edited by Chuck107 on Mon Oct 05, 2020 8:06 am, edited 1 time in total.
Alas, I find moderation of this forum too restrictive for my tastes, farewell.
neilpilot
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Re: Calling all NEC Electrical and DIY Experts. Help?

Post by neilpilot »

Chuck107 wrote: Thu Aug 20, 2020 7:48 pm Is that schedule 40?
When I ran a box into my tornado shelter the code as per the inspector was schedule 80.

But that's in my area with my inspector.

EDIT, I just enlarged the picture, it is 40, It may be ok I really don't know, depends on your local codes.
In my jurisdiction schedule 40 conduit is suitable for underground use. As shown above I'd have to use schedule 80 through any areas "where the conduit is exposed to physical damage".
sixty40
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Re: Calling all NEC Electrical and DIY Experts. Help?

Post by sixty40 »

NEC article 352 covers installation of rigid nonmetallic conduit (RNC), pvc40 is RNC. Your installation looks ok except you need to securely support the conduit with 3ft if termination to the panel/cabinet.
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Re: Calling all NEC Electrical and DIY Experts. Help?

Post by Sandtrap »

sixty40 wrote: Thu Aug 20, 2020 9:01 pm NEC article 352 covers installation of rigid nonmetallic conduit (RNC), pvc40 is RNC. Your installation looks ok except you need to securely support the conduit with 3ft if termination to the panel/cabinet.
Vertical unistrut with “U” bracket midway then?

Thanks
j🌺
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sixty40
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Re: Calling all NEC Electrical and DIY Experts. Help?

Post by sixty40 »

Sandtrap wrote: Thu Aug 20, 2020 9:21 pm
sixty40 wrote: Thu Aug 20, 2020 9:01 pm NEC article 352 covers installation of rigid nonmetallic conduit (RNC), pvc40 is RNC. Your installation looks ok except you need to securely support the conduit with 3ft if termination to the panel/cabinet.
Vertical unistrut with “U” bracket midway then?

Thanks
j🌺
As long as it’s “secured” and cannot wiggle around, somewhat subjective. Caddy makes a lot of conduit products, or unistrut or any metal channel with conduit strap would work as well.
rivercrosser
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Re: Calling all NEC Electrical and DIY Experts. Help?

Post by rivercrosser »

The only thing I would add. If its in an area where it could get hit by vehicles or equipment etc, I'd put a post or something in front of it just for peace of mind.
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Re: Calling all NEC Electrical and DIY Experts. Help?

Post by Sandtrap »

sixty40 wrote: Thu Aug 20, 2020 9:29 pm
Sandtrap wrote: Thu Aug 20, 2020 9:21 pm
sixty40 wrote: Thu Aug 20, 2020 9:01 pm NEC article 352 covers installation of rigid nonmetallic conduit (RNC), pvc40 is RNC. Your installation looks ok except you need to securely support the conduit with 3ft if termination to the panel/cabinet.
Vertical unistrut with “U” bracket midway then?

Thanks
j🌺
As long as it’s “secured” and cannot wiggle around, somewhat subjective. Caddy makes a lot of conduit products, or unistrut or any metal channel with conduit strap would work as well.
Ok.
I think I'll either go a double vertical unistrut with a base anchored in the slab. Then "U" bracket midway.
It's in the deep corner of the shop so minimal chance of damage from equipment.

That's all I can think of right now unless there's a "slicker" way of doing this that doesn't look "hokey".?

The slab guys set back my "sweep" from where I had it just inside the sill. I gotta work with how it ended up. Oh well. As long as it passes inspection.

j :happy
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sixty40
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Re: Calling all NEC Electrical and DIY Experts. Help?

Post by sixty40 »

Sandtrap wrote: Thu Aug 20, 2020 11:56 pm
sixty40 wrote: Thu Aug 20, 2020 9:29 pm
Sandtrap wrote: Thu Aug 20, 2020 9:21 pm
sixty40 wrote: Thu Aug 20, 2020 9:01 pm NEC article 352 covers installation of rigid nonmetallic conduit (RNC), pvc40 is RNC. Your installation looks ok except you need to securely support the conduit with 3ft if termination to the panel/cabinet.
Vertical unistrut with “U” bracket midway then?

Thanks
j🌺
As long as it’s “secured” and cannot wiggle around, somewhat subjective. Caddy makes a lot of conduit products, or unistrut or any metal channel with conduit strap would work as well.
Ok.
I think I'll either go a double vertical unistrut with a base anchored in the slab. Then "U" bracket midway.
It's in the deep corner of the shop so minimal chance of damage from equipment.

That's all I can think of right now unless there's a "slicker" way of doing this that doesn't look "hokey".?

The slab guys set back my "sweep" from where I had it just inside the sill. I gotta work with how it ended up. Oh well. As long as it passes inspection.

j :happy
What about just using an “L” bracket attached to one of the vertical struts for the panel, bolt bracket to channel and conduit clamp at other end. Anything will work actually. I would accept if inspecting it
sixty40
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Re: Calling all NEC Electrical and DIY Experts. Help?

Post by sixty40 »

Sandtrap wrote: Thu Aug 20, 2020 11:56 pm
sixty40 wrote: Thu Aug 20, 2020 9:29 pm
Sandtrap wrote: Thu Aug 20, 2020 9:21 pm
sixty40 wrote: Thu Aug 20, 2020 9:01 pm NEC article 352 covers installation of rigid nonmetallic conduit (RNC), pvc40 is RNC. Your installation looks ok except you need to securely support the conduit with 3ft if termination to the panel/cabinet.
Vertical unistrut with “U” bracket midway then?

Thanks
j🌺
As long as it’s “secured” and cannot wiggle around, somewhat subjective. Caddy makes a lot of conduit products, or unistrut or any metal channel with conduit strap would work as well.
Ok.
I think I'll either go a double vertical unistrut with a base anchored in the slab. Then "U" bracket midway.
It's in the deep corner of the shop so minimal chance of damage from equipment.

That's all I can think of right now unless there's a "slicker" way of doing this that doesn't look "hokey".?

The slab guys set back my "sweep" from where I had it just inside the sill. I gotta work with how it ended up. Oh well. As long as it passes inspection.

j :happy
What about just using an “L” bracket attached to one of the vertical struts for the panel, bolt bracket to channel and conduit clamp at other end. Anything will work actually. I would accept if inspecting it
ironman
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Re: Calling all NEC Electrical and DIY Experts. Help?

Post by ironman »

Here are the relevant articles in the 2020 NEC:

352.10(F) "PVC conduit shall be permitted for exposed work. PVC Conduit used in exposed areas of physical damage shall be identified for the use" My comments: physical damage is loosely defined in the NEC and is up to the AHJ's discretion.

352.30(A) "PVC shall be securely fastened within 3 feet of each outlet box, junction box, ..." My comments: drop some unistrut and slap a strut strap on the riser.

If these are feeder conductors the relevant code is the NEC. If they are service conductors (prior to metering equipment) from the POCO, the POCO rules apply and may require Schedule 80 (this is true in my location).

Hope this helps.
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Re: Calling all NEC Electrical and DIY Experts. Help?

Post by Crimsonandclover »

Vertical units unistrut with a midway U bracket will satisfy NEC support requirements.
If I was doing this installation I would use schedule 40 ridged galvanized conduit for the exposed portion of the run for protection. This area could be subjected to damage from moving lawnmowers or tools. At some point in the conduit run, the PVC under the slab has a 90 degree fitting. If you can chisel out the concrete you may be able to adapt/transition to galvanized conduit for the exposed portion of the conduit.
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Re: Calling all NEC Electrical and DIY Experts. Help?

Post by Sandtrap »

Crimsonandclover wrote: Fri Aug 21, 2020 7:50 am Vertical units unistrut with a midway U bracket will satisfy NEC support requirements.
If I was doing this installation I would use schedule 40 ridged galvanized conduit for the exposed portion of the run for protection. This area could be subjected to damage from moving lawnmowers or tools. At some point in the conduit run, the PVC under the slab has a 90 degree fitting. If you can chisel out the concrete you may be able to adapt/transition to galvanized conduit for the exposed portion of the conduit.
I thought of this as I was installing the conduit with pvc cement ...... :oops:
It would’ve looked much cleaner.

Alternative might be to frame it out and chaise it.
Shucks
j🌺
Last edited by Sandtrap on Fri Aug 21, 2020 9:50 am, edited 1 time in total.
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Sandtrap
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Re: Calling all NEC Electrical and DIY Experts. Help?

Post by Sandtrap »

ironman wrote: Fri Aug 21, 2020 7:27 am Here are the relevant articles in the 2020 NEC:

352.10(F) "PVC conduit shall be permitted for exposed work. PVC Conduit used in exposed areas of physical damage shall be identified for the use" My comments: physical damage is loosely defined in the NEC and is up to the AHJ's discretion.

352.30(A) "PVC shall be securely fastened within 3 feet of each outlet box, junction box, ..." My comments: drop some unistrut and slap a strut strap on the riser.

If these are feeder conductors the relevant code is the NEC. If they are service conductors (prior to metering equipment) from the POCO, the POCO rules apply and may require Schedule 80 (this is true in my location).

Hope this helps.
220v 40 Amp Subpanel.

Thanks!!!
j🌺
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suemarkp
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Re: Calling all NEC Electrical and DIY Experts. Help?

Post by suemarkp »

There is an information note in article 352 that says: "PVC Conduit, Type Schedule 80, is identified for areas of physical damage."

So you could cut off the conduit just above the floor, glue on a coupler, and transition to sch 80 PVC and be good for the physical damage requirement (if you can find sch 80 electrical PVC conduit at your supplier). Ream the inside well so pulled wire doesn't snag on the inner edge because sch80 has a smaller inside diameter than sch 40. Since the conduit is out from the wall, I'd use strut support or something anyway to further protect and support it. Physical damage is always a pain because the NEC provides only some guidance. The rest is inspector interpretation/judgement.

PVC conduit support varies with diameter. For 1.25" to 2", it must be supported (clamped) every 5 feet and within 3' of any box, conduit body, or termination.
Mark | Kent, WA
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Re: Calling all NEC Electrical and DIY Experts. Follow Up: Thanks Everyone.

Post by Sandtrap »

OP: Thanks everyone for your help and great advice. I updated the original post to show the results. Feel free to add any more great advice. Don't want to get blind sided by the inspector.

mahalo
j :happy
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