NM cable in basement

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Re: NM cable in basement

A lot of the service work I do takes me to attics, some 50 yrs old some nearly new. I have never seen NM cable installed in this area in unfinished attics other than simply laid across the top of the ceiling joists. I am not saying whether its code compliant or not but probably 100% of the houses around here are done this way apparently with approval by the inspector.
 
Re: NM cable in basement

Do we see the problem? how can we compete and do this right while others throw there wire over the trusses?
If inspectors forced this rule then within days we would have compliance.Im in full support that this should be enforced ,i have walked many of attics and walked on wires.

[ January 30, 2004, 04:50 PM: Message edited by: jimwalker ]
 
Re: NM cable in basement

Jim
I teach a class with the inspectors here every wednesday night. When we went over this requirement, they were stunned to see it in the NEC. Guess what is being enforced in this area these days :) Needless to say the contractors are not too happy.

Pierre
 
Re: NM cable in basement

...So is the basement finished because of the drop ceiling or is it not finished?

Of COURSE it's finished! What do you think the ceiling is for?

This is a poorly worded article so you have to apply common sense to understand the intent. Running boards are for physical protection where the cables can be stepped on, articles placed on them or hung off of them. None of this is going going to happen if the cables are above a hung ceiling.
 
Re: NM cable in basement

How about teaching our inspectors and for that matter our electricians too.
You just pointed out the problem.Even inspectors did not know this was a violation.With egg on face i will admit that i have violated this for over 20 years.Please don't ask me to go back and fix,im too old to get them all corrected.
 
Re: NM cable in basement

By pierre: This requirement is not only for the top of floor joists, but the surface of studs and rafter up to 7 feet from the top of joists or the floor. This means that in most attics that the wiring needs to be protected or run through bored holes.
Click to expand...
If the scuttle does not have a permanent stairs or ladders, It only has to be protected op to 6' from the scuttle hole

320.23(A) Where Run Across the Top of Floor Joists. Where run across the top of floor joists, or within 2.1 m (7 ft) of floor or floor joists across the face of rafters or studding, in attics and roof spaces that are accessible, the cable shall be protected by substantial guard strips that are at least as high as the cable. Where this space is not accessible by permanent stairs or ladders, protection shall only be required within 1.8 m (6 ft) of the nearest edge of the scuttle hole or attic entrance.

So now we can discuss :p LOL
 
Re: NM cable in basement

Wayne are you referring to the NCC?


National Chicken Code. :D

[ January 30, 2004, 06:54 PM: Message edited by: iwire ]
 
Re: NM cable in basement

A question if i may.If the trusses are not designed for storage and there is no equipment in the attic ,just why would we put pull down stairs in?
And stairs or not what keeps the wires from being walked on?
 
Re: NM cable in basement

Speaking of equipment, say a few years later someone installs a air handler for A/C or heat pump, now is all that attic wiring is now in violation since the equipment must be accessible for service? :roll:
 
Re: NM cable in basement

Originally posted by electricman2:
Speaking of equipment, say a few years later someone installs a air handler for A/C or heat pump, now is all that attic wiring is now in violation since the equipment must be accessible for service? :roll:
Click to expand...
A furnace in an attic has several requirements.

1) The trusses must be designed to carry the load
2) 22"x30" attic access
3) 24" wide pathway to the appliance, not longer than 20 feet.
4)30"x30" clear space at the location of the equipment where such service is required.
5) Light, switch and receptacle outlet.


Considering the fact that the pathway is required, I would say that NM cables on top of the trusses is not an issue. I can't think that a service person, given the choice, would walk on the trusses as opposed to a nice level and sheathed pathway.

References: 2000IRC, Sec M1305.1.3, 2002 NEC 210.63 and 210.70
 
Re: NM cable in basement

Originally posted by pierre:
Scott
You have hit on a running discussion we have been having in our jurisdiction.
(C) is a subsection of 334.15 Exposed Work. AS Scott has mentioned, behind ceiling panels, the wire is exposed. So is the basement finished because of the drop ceiling or is it not finished. I believe that the building official decides if it is finished or not and then you go from there.

Pierre
Click to expand...
Pierre, I'm curious what the next step is. If the building official decides that the basement is finished, due to the drop ceiling, then 334.15 (C) does not apply. So running boards are not required based on that article.

However, as Scott suggests, the wiring may still be considered exposed, based on the definition of exposed wiring ("On or attached to the surface or behind panels designed to allow access.") This means that the wiring must still comply with 334.15 (B):

"Protection from Physical Damage. The cable shall be protected from physical damage where necessary by conduit, electrical metallic tubing, Schedule 80 PVC rigid non-metallic conduit, pipe, guard strips, listed surface metal or nonmetallic raceway, or other means ."

Those "other means" could be running boards. So, the question of whether guard strips, or running boards are necessary above a dropped ceiling depends on whether they are deemed "necessary" to physically protect those wires. In my opinion, If there is a significant risk of damage to those wires then they must be protected even if they are above a dropped ceiling. However, the dropped ceiling eliminates most of the risks that I can think of. With a dropped ceiling people wouldn't be tempted to hang things from the wire. Also you couldn't pull at, or cut the wire accidently like you could without the drop ceiling. (I can picture a gawky teenager taking his alpine skiis into the basement to give them a wax job, but catching the tip on a low wire, or even cutting it with the sharpened edge of his ski.) So, it seems to me that the wires above a drop ceiling simply do not need any special protection, even though they are technically "exposed".

Jason Rand
 
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