My pipe is full

[BillGalbraith]

The riser pipe running from my subpanel up the face of the concrete block wall is full. I thought there was going to be room to run the three more cables that I need, but the top appears to be constricted.

If I could, I'd punch a hole in the back of the box and run it up inside the concrete block, but the box is mounted on a poured cell, so it is full of concrete.

The exisiting pipe is partially encased in stucco, so removing it and replacing it will be difficult.

Can I just add another pipe onto the box for the wire that I need?

Oh, and I guess this would be a good thing to specify to an electrician when they install it. Another good thing to specify is that you want all of your switches and receptacles wire wrapped instead of back-stabbed, even if it is allowed by code.

 

[jay50]

They must have used awg14 for the light/wall receptacle circuits; that's the min size permitted by code. Those devices permit back-stabbing to make connection with awg14. I've always used AWG12 for those same circuits; they can not be backstabbed; only wrapped around the screws.

 

[walrus]

; they can not be backstabbed; only wrapped around the screws.

Buy spec grade devices and you can back stab them. They aren't like the spring loaded back stabs, you tighten the screw which clamps the wire in place. Its all I use

 

[BillGalbraith]

Okay, after measuring and scratching my head, I think I can drill straight through the subpanel box into the concrete block, and miss the poured cell, and run the additional wire up inside the concrete block. Is this an acceptable way to do it, or should I get another pipe, or replace the existing pipe with a larger one (my least favorite idea).

 

[6768rogues]

Check the electrical code. The ampacity of wires decreases as the number in a bundle increases. The ampacity of a wire is a function of the temperature rating of its insulation, and too many wires clustered close together cannot cool efficiently. If you have a conduit that is so full that there is no room for another wire, you might have a problem brewing.

 

[rockwithjason]

there is no physical protection for the wire in the block cavity. besides being difficult, i would bet you would cut a wire in the process. run a new pipe for your stuff and while you are there you might look at stubbing up a few spares. if you insist on running in the block you will need to find some kind of way of bushing the opening in the panel can. code on this one is iffy at best

 

[BillGalbraith]

Problem solved. I'm an idiot.

I never looked at the pipe, since it was on the outside of the block wall, and I could just barely see the top of it. There is a clamp at the top of the pipe to hold the wires coming out of it. Will have to investigate further. Is this clamp meant to limit the number of wires in the conduit, so that you don't fill the conduit up, thereby causing a heat problem?

 

[walrus]

. Is this clamp meant to limit the number of wires in the conduit, so that you don't fill the conduit up, thereby causing a heat problem?

No. Its meant to clamp wires in the pipe. The clamp would be listed for so many cables? What that amount is or kinds of cable is,????

 

[BillGalbraith]

So what is the purpose of clamping the wires? Stress relief for the weight of the wire dangling down into the subpanel? It's only a 4 foot drop, so not too bad.

 

[Norcal]

Strain relief is required of all cables, & you need to check the listing of the connector, if more then 1 cable is allowed, more then 2 cables in 1 connector is unlikely.

 

[BillGalbraith]

Okay, but there is no room to add all the wires that I need to. So, can I add another vertical conduit to my subpanel, or do I have to replace the existing one with a larger one?

 

[walrus]

Okay, but there is no room to add all the wires that I need to. So, can I add another vertical conduit to my subpanel, or do I have to replace the existing one with a larger one?

You can add another conduit

 

[BillGalbraith]

I checked with Homer. The metal pipe is only available in 10 foot sections, at $32 for 10 feet. I need 4 feet. Can this conduit be PVC?

 

[walrus]

I checked with Homer. The metal pipe is only available in 10 foot sections, at $32 for 10 feet. I need 4 feet. Can this conduit be PVC?

Depends on what you're doing. Are you just sleeveing romex up the wall? Unless its against local code I'd say yes

 

[BillGalbraith]

Just sleeving romex up the wall.

Thanks for the responses.

 

[Aceman]

there is no physical protection for the wire in the block cavity

Romex doesn't need any extra protection when fished in block. 334.10(A)2

 

[BillGalbraith]

Just to finish out this tread, I replaced the conduit coming up out of the subpanel box. It already was PVC, not steel. Just bought a new base (about $6) and a new piece of 2 inch conduit (about $4). Going from 1-1/2" to 2" gives me 77% more room in the conduit, plenty of room for the additional wiring that I had to run. Took about an hour to change out. That aspect was important to me, as the house a/c is wired through this panel, so I had to shut the a/c off for an hour.

Thanks for all the help on this, guys. It turned out to be a non-event.

 

[Todd.Brock]

I hate that. All the planning, fretting and figurin' all for nothing.. I hate when I over engineer a problem just as much as being under prepared...