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-   -   Mounting new load center to concrete block wall. (http://www.diychatroom.com/f18/mounting-new-load-center-concrete-block-wall-148756/)

speedster1 06-30-2012 09:01 PM

Mounting new load center to concrete block wall.
 
Is it okay to mount a new GE 200A load center directly to a concrete block wall with 1/4" tapcons or do I need to build a wooden platform with treated 2x4's and plywood in order to mount the box onto it. The box would actually be above ground level as only the first 3 courses of block in my basement are below drainage.

Techy 06-30-2012 10:22 PM

you can mount directly to the concrete, but it's easier to secure the cables if mounted to a wooden backer

speedster1 07-01-2012 07:42 AM

Quote:

Originally Posted by Techy (Post 955132)
you can mount directly to the concrete, but it's easier to secure the cables if mounted to a wooden backer

I guess it makes sense from a cable management aspect. I hadn't thought about that. I was thinking more in lines of possible condensation problems. I've never noticed any condensation on my walls but I wondered baout electrical codes and such.

I have another question maybe you might answer. I plan to enter the box with my supply line by dropping straight down out of the meter socket about 2 feet and immediately turning 90 degrees and going straight through the wall into the back of my load center. I plan to use 2" PVC conduit. I'd literally only need ~6' of wire. I've noticed that the sheathed wire is extremely stiff. How easy is it to get that stiff wire through the 90 degree elbow? Is it permissible to cut the sheath off the cable and run the 4 wires individually if needed?

k_buz 07-01-2012 07:47 AM

What size wire are you using and what brand of panel?

Speedy Petey 07-01-2012 07:53 AM

Quote:

Originally Posted by Techy (Post 955132)
you can mount directly to the concrete, but it's easier to secure the cables if mounted to a wooden backer

Yup. I use 24"x48" minimum. 32"x48" typical. Obviously this is a 4x8 sheet cut two or three times.

speedster1 07-01-2012 08:28 AM

Quote:

Originally Posted by k_buz (Post 955286)
What size wire are you using and what brand of panel?

I assume 4/0 aluminum. Isn't that whats recommended?

The Panel is a GE 200A 40 circuit/32 space box.

k_buz 07-01-2012 08:37 AM

You cannot come into the back of the panel. You don't have the depth (of the panel) to meet wire bending requirements. You will have to come into the top, sides, or bottom of the panel.

Diameter of 4/0 XHHW = .638 in
300.34 requires 8x diameter
Depth needed .638x8=5.1 in

brric 07-01-2012 09:08 AM

Quote:

Originally Posted by k_buz (Post 955302)
You cannot come into the back of the panel. You don't have the depth (of the panel) to meet wire bending requirements. You will have to come into the top, sides, or bottom of the panel.

Diameter of 4/0 XHHW = .638 in
300.34 requires 8x diameter
Depth needed .638x8=5.1 in

Don't you ever enter the back of a meter socket? Why are there ko's in both the back of a socket and a load center?

a_lost_shadow 07-01-2012 09:10 AM

Quote:

Originally Posted by speedster1 (Post 955284)
Is it permissible to cut the sheath off the cable and run the 4 wires individually if needed?

Wires are required to be marked with a bunch of information such as the type, gauge, insulation rating, etc. (310.120 NEC 2011). Unless all this information is printed on each of the individual wires, you're required to leave the sheathing intact.

brric 07-01-2012 09:11 AM

Quote:

Originally Posted by speedster1 (Post 955284)
I guess it makes sense from a cable management aspect. I hadn't thought about that. I was thinking more in lines of possible condensation problems. I've never noticed any condensation on my walls but I wondered baout electrical codes and such.

I have another question maybe you might answer. I plan to enter the box with my supply line by dropping straight down out of the meter socket about 2 feet and immediately turning 90 degrees and going straight through the wall into the back of my load center. I plan to use 2" PVC conduit. I'd literally only need ~6' of wire. I've noticed that the sheathed wire is extremely stiff. How easy is it to get that stiff wire through the 90 degree elbow? Is it permissible to cut the sheath off the cable and run the 4 wires individually if needed?

Unless the individual conductors are marked as to their insulation types they may not be removed from a cable assembly and used as individual conductors.
Damn, I'm slow.

k_buz 07-01-2012 09:24 AM

Quote:

Originally Posted by brric (Post 955324)
Don't you ever enter the back of a meter socket? Why are there ko's in both the back of a socket and a load center?

I can't remember the last time I have come into the back of a meter socket...99% of the homes here have basements, therefore we come out of the bottom of the meter. There have been times I was able to come into the back of panels, but like I said, it depends on the depth of the panel and the size of the wire.

This GE panel says 3.8"
A Murray (at HD) says 5"

So, the Murray with 3/0 CU would be ok coming into the back of the panel, but not with 4/0.

As for the reason, I assume that the enclosures are made for multiple different panels...150A could be the same as 200A. You can also use those KO's for something other than service entrance cables.

speedster1 07-01-2012 09:50 AM

1 Attachment(s)
Here is a schematic I drew. As you can see I want to drop down from the meter socket approximately 12-18 inches then turn 90 degrees and go directly through the block wall. I'd continue to run the 2 inch PVC through the block wall and connect to the back of my meter. It seems like a better idea than coming in the side or top of the meter simply because it's one less 90 degree turn I have to make. It would require 1 simple 90 degree turn. Only issue is how tight I can make that turn. What kind of fitting is typical for this type of application? A 90 degree sweep or one of those 90 degree boxes with a weatherproof screw plate ?

I could use 2.5" PVC if I had to (prefer not to simply because I already have 2" supplies). Their are knockouts for both sized on both the meter and load center.

I'm not really sure what wire I should use. I'm just basing it on what the electrical supply house recommended that sold me the Meter box and conduit. I thought they told me 4/0, 4/0, 4/0. I assume that's for the hots and neutral. I think they said #2 for the ground. This sound right?

If I had to couldn't I just buy single 4/0 aluminum wire that's marked properly and run it through separately?

k_buz 07-01-2012 09:57 AM

Where is grade?

speedster1 07-01-2012 10:01 AM

Quote:

Originally Posted by k_buz (Post 955339)
I can't remember the last time I have come into the back of a meter socket...99% of the homes here have basements, therefore we come out of the bottom of the meter. There have been times I was able to come into the back of panels, but like I said, it depends on the depth of the panel and the size of the wire.

This GE panel says 3.8"
A Murray (at HD) says 5"

So, the Murray with 3/0 CU would be ok coming into the back of the panel, but not with 4/0.

As for the reason, I assume that the enclosures are made for multiple different panels...150A could be the same as 200A. You can also use those KO's for something other than service entrance cables.

Okay I just re-read your post and realized you were talking about the physical depth of the load center. For some reason in my head I thought you were talking about the 90 degree bend in the service wire before it goes trough that wall.

As for the depth of the box, I planned on stripping the outer sheathing where it comes into the box. Surely I'd be able to bend and loop those aluminum wires and get them into position without harming them. At least it seems like I should be able to do that. I thought the bigger issue was being able to bend the sheathed wire outside the house.

speedster1 07-01-2012 10:02 AM

Quote:

Originally Posted by k_buz (Post 955382)
Where is grade?

below the bottom of load center. The grade would be below the 90 degree entry.


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