Installed meter base on exterior wall (200A underground). Installed 200A service panel on interior wall directly behind meter base, but slightly higher since ground level and floor level differ (crawlspace foundation). Two questions for you guys:
1. Went to Lowes and requested cabling for this particular utility company. The guy in the electrical dept (seemed to be knowledgable) sold me SER 4-conductor 4/0 aluminum. The meter base has no provision for a fourth conductor other than the bare copper for the grounding elctrode. I’m thinking a 3-conductor 2/0 copper would have been the preferable choice, and it meets the utility requirements. Should I take the SER cable back and swap it?
2. Since the meter base and SEP are not directly back-to-back, I’ll have to route the service entrance conductors vertically up through the CENTER of the stud bay about 20 inches. While I know that most cables don’t have to be “protected” within a stud bay, I’m not sure about service conductors. The IRC2003 states the following, which seems contradictory to me:
E3505.5 Protection of service cables against damage. Above-ground service-entrance cables, where subject to physical damage (like a misplaced nail through the drywall perhaps?), shall be protected by one or more of the following: rigid metal conduit, intermediate metal conduit, rigid non-metallic conduit suitable for the location, electrical metallic tubing or other approved means.
then there’s this…
E3702.2.2 Cable installed through or parallel to framing. Where cables are installed through or parallel to the sides of rafters, studs or floor joists, guard strips and running boards shall not be required…
Can you guys help me make sense of this?
Thanks.
New knowledge is priceless.
Used knowledge is even more valuable.
Replies
The Lowe's guy is wrong. 3-conductor is what you use upstream of the service disconnect.
I don't know what IRC2003 is, but the text looks similiar to the National Electric Code.
You don't need to treat the SE cable in the wall any differently than other wiring.
Service cables are generally installed out of doors and often exposed, and it's pretty clear this is the main concern of the first section you quote.
The second quote is for wiring inside a building, which is not the same thing.
Ed
Thanks, Ed. The IRC2003 refers to the International Residential Builders Code. That's what the local BI uses for enforcement.New knowledge is priceless.
Used knowledge is even more valuable.
Our electrical utility and city inspectors would demand the use of continuous conduit for any service entrance from the weatherhead to the breaker panel. Better ask them before making expensive decisions not to use conduit.
BTW, your underground wire is in conduit, isn't it?
I'm also curious - Did the utility pay for the wire from their pole to the meter on the back of the house? Ours (in areas with overhead lines) will require meter to be placed on owner-supplied pole in alley and require owner to pay for buried line to the house.
Edited 6/13/2007 2:14 am ET by jimbotoo
"Our electrical utility and city inspectors would demand the use of continuous conduit for any service entrance from the weatherhead to the breaker panel."
That's the only thing that makes "safe" sense to me. I'm thinking that every wire in a stud bay should either be protected by an overload device or placed in conduit. But as you can see from my original post, the code is not crystal clear about it. I'd rather err on the side of safety, so I'm going to make sure it's protected one way or another.
"BTW, your underground wire is in conduit, isn't it?"
It will be. Hasn't been installed yet.
"I'm also curious - Did the utility pay for the wire from their pole to the meter on the back of the house?"
The utility charges a $350 fee to trench and lay the cable from their pole to my meter base. That includes conduit and wire.New knowledge is priceless.
Used knowledge is even more valuable.
"Our electrical utility and city inspectors would demand the use of continuous conduit for any service entrance from the weatherhead to the breaker panel."
Wow. So no houses have SE cable running on the outside of the house down from the weatherhead ? I've seen that everywhere I've lived.
I lived in San Francisco for a while........everything service-related in pipe. RIGID STEEL pipe, no pvc allowed. It was a big day in an electric shop when they could afford to buy a hydraulic pipe bender.
Frank has it right : that is not the norm. No worries about it unless you live in one of those areas.
BTW, for the OP, wire inside finished walls is considered to be protected from physical damage. Only caveat is that is cannot be fastened within 3/4" of the face of structural framing. For an unfused SE cable though I like that idea of the 2 X 4 to keep it further back from the drywall.
Ed
Short run of SE cable in stud bay does not need nail protection here in the situation you describe. I have been asked to nail a 2x4 or such across the stud bay to clamp the SE cable to when there has been more than a foot or so run below the service panel. This also helps locate the SE cable about 1 1/4" from the drywall for nail damage.
However, on the outside of the building, below the meter base, I have to protect the SE cable IF the meter is on a sidewalk or other concrete surface. Grass does not need protected SE, just a hard walking surface. Typically I have done this with PVC conduit in the normal manner*, but have also used 2" PVC conduit split up the back side when a sidewalk was close enough for the inspector to count, but there was grass below the meter..... and I didn't want to remove the SE to rewire in conduit.
Some jurisdictions require conduit for everything. They are not the norm so do not worry about them. Unless you move there!
*Normal manner meaning just conduit on the SE up to the wall, terminating in an LB, not through the wall, and no conduit inside the wall.
Frank DuVal