Service Entry Exposed NM Cable

[Stuart Brooks]

NEW CONSTRUCTION: I keep running into service entry installations where the NM SEC from the meter base is exposed for lengths of 6 inches t o 18 inches before it goes through the wall to the main service panel. The service is underground and when installed (not done yet in this picture) the power company runs the cable through conduit to the meter base. I do see a lot of installations where if a short run is required on the exterior from the meter base to the service panel, it is also enclosed in conduit. BUT, I also find a lot of the cable exposed as shown. I write it up as a deficiency, NM cable exposed to inadvertent damage (especially with weed whackers). The various AHJs in the area apparently are just fine with the installation. Am I out in left field?

[Robert Meier]

First point, that is SE cable not NM cable. Secondly, it is permitted as shown to leave the meter enclosure and enter into the structure and on to the panel as long as it is not subject to physical damage. Subject to physical damage is not defined in the NEC so it's up to the AHJ to decide if the SE cable requires protection. Also if the SE cable is run on the outside of the structure it's length permitted is unlimited.

My two cents, if the AHJ has already determined that protection is not required you shouldn't be writing it up that it is.

[Jerry Peck]

First point, that is SE cable not NM cable. Secondly, it is permitted as shown to leave the meter enclosure and enter into the structure and on to the panel as long as ...

... the service equipment is located directly on the other side of that wall.

[Robert Meier]

... the service equipment is located directly on the other side of that wall.

Yup, and nearest the point of entry is right up there with subject to physical damage, neither are defined by the NEC. I read somewhere that Washington State allows up to 15' of entry into the structure. That would allow the installation to not be on the other side of the wall.

[Jim Port]

I don't see that as subject to damage, especially from weed wackers. That cable looks to be at least 2' above grade.

[Jerry Peck]

I don't see that as subject to damage,

I agree, but I do see it as a country road ;) for water to enter the service equipment from the outside.

[Jim Port]

I would expect silicone caulk or duct seal at a minimum to seal the siding/cable joint. Maybe I expect too much.

[Robert Meier]

I would expect silicone caulk or duct seal at a minimum to seal the siding/cable joint. Maybe I expect too much.

Looks like spray foam in the photo. Is that water resistant?

http://www.inspectionnews.net/home_inspection/attachments/electrical-systems-home-inspection-commercial-inspection/24762d1330403677-service-entry-exposed-nm-cable-exposedentrycable.jpg

[Jerry Peck]

I would expect silicone caulk or duct seal at a minimum to seal the siding/cable joint. Maybe I expect too much.

That was one path I was considering, the other was down through the cable sheath itself as there is no drip loop. Not sure how much water would be generated in the meter can or how much could run down inside that outer sheath.

That is why I said 'country road' instead of 'super highway' like raceway would be. ;)

[Jim Port]

Looks like spray foam in the photo. Is that water resistant?



The finish siding isn't up yet. It is fairly resistant as it is a closed cell structure.

As far as the moisture in the can, the meter should be 3R rated and the sheath should extend up past the connector inside. The water would drain out before flowing into the sheath.

[paul hardy]

also the equipment needs 1/4" airspace between the enclosure and the surface (312.2 2008 NEC) if you run siding up to the meter and seal around it you lose that space. The wall covering should be in place before the meter was mounted.

[Stuart Brooks]

1. The service panel is on the other side of the wall, about 2 feet below the entry point.
2. I have seen water in the service panel when the SE cable is installed like this. This was right after a night rain. The outside of the cable wasn't wet between the panel and the entry point through the wall. That implied it was coming through the inside of the cable.
3. Usually, pipe seal is used to seal the hole in the siding. I don't know if the foam is water proof. It's the same product the builder uses as fire-stop inside. But that is a good point. I'll see if I can find info on the product.

[Stuart Brooks]

First point, that is SE cable not NM cable. Secondly, it is permitted as shown to leave the meter enclosure and enter into the structure and on to the panel as long as it is not subject to physical damage. Subject to physical damage is not defined in the NEC so it's up to the AHJ to decide if the SE cable requires protection. Also if the SE cable is run on the outside of the structure it's length permitted is unlimited.

My two cents, if the AHJ has already determined that protection is not required you shouldn't be writing it up that it is.

NM - non metallic and I used it as shorthand; if a cable doesn't have a metallic outer covering it is NM. The AHJs get a lot of things wrong or miss them all together. It goes both ways. I've seen them make builders do the most idiotic things as well as let things slide.

[Robert Rolleston]

I prefer to go out the back of the meter socket to enter the building. And use conduit all the way up to the weather head. As long as you seal the back of the meter socket where the hole is it keeps the water out.

[Robert Meier]

NM - non metallic and I used it as shorthand; if a cable doesn't have a metallic outer covering it is NM. The AHJs get a lot of things wrong or miss them all together. It goes both ways. I've seen them make builders do the most idiotic things as well as let things slide.

In the context of the NEC, NM cable and SE cable are similar but not the same. IMO they should not be used interchangeably.

[Jerry Peck]

I don't know if the foam is water proof. It's the same product the builder uses as fire-stop inside.

Is that foam the pinkish/reddish/orangish color type?

If not, it likely is not approved or listed for use as draftstopping or firestopping.

The foam which is listed for this use typically has a reddish dye in it, and depending on the color of the foam, the reddish dye may end up as pinkish, reddish, or orangish in color.

[Stuart Brooks]

Is that foam the pinkish/reddish/orangish color type?

If not, it likely is not approved or listed for use as draftstopping or firestopping.

The foam which is listed for this use typically has a reddish dye in it, and depending on the color of the foam, the reddish dye may end up as pinkish, reddish, or orangish in color.

Orange

[Don Hester]

Funny thing happened on the way to the forum.

I was just back in the mid west and say the type of SEC for the first time on a relative's home.

I never see this in my neck of the woods. All SEC are in conduits.

[bob smit]

As stated in a previous post, code requires sheathing to extend at least 1/4" inside an enclosure. The U-Co will also have this type of requirement.

The problem usually, in my experience, is a result in the following; slice in the extended sheathing at the bottom of an enclosure, lack of sealing compound/caulk where the mast threads into the top of the meter can,
improper 'goose-neck' and/or drip-loop, pin hole or slice in the sheathing anywhere along its length.

P.S. watch around the cable clamps:eek:

[bob smit]

Here's one, NEC 314.17(B) & (C)

[H.G. Watson, Sr.]

1. The service panel is on the other side of the wall, about 2 feet below the entry point.
2. I have seen water in the service panel when the SE cable is installed like this. This was right after a night rain. The outside of the cable wasn't wet between the panel and the entry point through the wall. That implied it was coming through the inside of the cable.
3. Usually, pipe seal is used to seal the hole in the siding. I don't know if the foam is water proof. It's the same product the builder uses as fire-stop inside. But that is a good point. I'll see if I can find info on the product.

Has to be weather tight. Last time I checked it still snows (albiet occasionally in certain areas), freezing rain, and the wind still blows in Virginia. Service-entrance conductors shouldn't be entering the interior Service equipment from top or back of panel.

I recall you were quite clear this was not a drop but underground service - lateral supplied.

See NEC Article 230, Parts I, III, IV and for the Service Equipment Part V.

[Garry Blankenship]

Donno what the building finish will be above that masonary work, but it might partially, if not entirely, cover that SE cable. Agree a weed whacker is no concern, but if that SE cable ends up covered by the "exterior", it may be a mute concern. Otherwise it will be difficult to seal that cable well enough to insure no moisture can travel on it.

[bob smit]

Robert, if you look again at my post #19 you will read my mention of poco also having spec sheets as to installation requirements.
My code reference was one off the top of my pee-brain. Asking for more is futile at this time... tired. I expected many to chime in additional ref's:cool: