General wiring requirements above ceiling tiles

[tonype]

I am an engineer that performs building inspections for potential purchasers. I often see sloppy/improper wiring above suspended ceiling tiles in office and other commercial type buildings. I always tell the client that extensive "cleaning up" is needed and that they must retain a licensed electrical contractor. What I am looking for is some concrete guidelines or references with respect to how wiring should be installed. This includes power and LV wiring. What are support spacing requirements? I often see wires just draped between steel trusses and other structural members (also to the top of ductwork). When are cable trays needed?, etc. Is there some publication I can get on this (or a code section devoted to this topic)? Any help would be appreciated.

 

[jtester]

Re: General wiring requirements above ceiling tiles

tonype
There have been a number of recent changes to the NEC, 1999 and 2002 in particular, that somewhat addressed sloppy cable installation. See 725.6 725.58, and similar sections in Articles760, 770, 800, and others. Many sloppy installations may be grandfathered in because of the age of installation. You might want to check more about that.
Jim T

 

[tonype]

Re: General wiring requirements above ceiling tiles

Jim:

Thanks for the speedy reply - I will check into those sections. A specific building I have in mind is one that I looked at yesterday - built circa 1983.

Tony

 

[jimwalker]

Re: General wiring requirements above ceiling tiles

In 20 years i am sure it has some remodeling and typical work performed by maintence men.This could be a rough inspection.Some items were probably ok 20 years ago and some were add ons no telling when.Since this could be costly to the new owner i would suggest you get a local EC to go with you or if possible a county inspector.The code violations could cost thousands easily so spend a few hundred getting an estimate from an EC to bring it to min code.Otherwise when new owner remodels to suit there needs they get trapped into fixing everything.I been there and seen the messes created.

 

[tonype]

Re: General wiring requirements above ceiling tiles

Jim:

My report will be CYA time. The building likely had renovations over the years. I lost count after 30 open junction boxes (some with wires sticking out and never tucked in after the wirenuts were installed). I could have pulled on some of the wires and gathered several feet of slack from the way the wires were draped over the structural steel and ducts. The only area that was done properly was in a section occupied by a large utility in this area (NJ) - nothing hanging below the steel, use of conduit, etc. They had a very good EC.

Anyway, thanks for the reply - I will be recommending extensive corrective action.