NEC 300.4(C) Don't Let Conductors Lay On Top Of Suspended Ceiling Tiles - Pet Peeve of the Day

[jar546]

The code says this: (posted for educational purposes under fair use)

(C) Cables Through Spaces Behind Panels Designed to Allow Access.
Cables or raceway-type wiring methods, installed behind panels designed to allow access shall be supported according to their applicable articles.

What it means:
Imagine you've got a room with a panel on the wall or a ceiling with lift-up tiles – these are designed so you can easily get to the stuff behind or above them, right? The rule here is about how to handle wires and cables in these accessible spaces.

If you've got cables or pipes (raceways) for wires running behind these panels or above these ceilings, you can't just let them hang loose or lay them on the ceiling tiles. That would be like leaving your tools scattered on a workbench – it gets messy and makes it hard to use the space.

Instead, these wires and cables need to be properly supported and secured. This is not just for neatness; it's a safety thing. Imagine trying to access a panel or lift a ceiling tile and having a bunch of wires fall on you – not good. So, these cables should be fixed in place following specific rules (like those in sections 300.11(B) and 300.23 of the code).

The same goes for other types of wiring like low-voltage, optical fiber, broadband, and communications cables. Just because they're not carrying a lot of power doesn't mean you can let them block access. They need to be neatly tucked away and secured, so they don't get in the way when someone needs to reach equipment or wiring behind these panels or above these ceilings.

 

[Mr. Inspector]

This is also a pet peeve of mine.
Today I did an inspection of a 1,500 sq ft existing tenant space for a change of occupancy B to M and alterations. All they did was installed 3 new pendant lights from the suspended ceiling and a few new receptacles. At the inspection after lifting a ceiling panel and moving the insulation that is laying on it I saw tons of existing Romex, MC wiring and junction boxes, and a disconnect laying on top of the insulation. Some of the wiring just ended with no box and some were in large coils. and this was just in the immediate area of where I took out the one panel, who know what it looked like in the rest of the area above the supposed ceiling. This could have been the first inspection since the state required any permits and inspections. I know the NEC says unused wiring is to be removed but this would be a huge undertaking for the electrician which would have been at least 10 times of more work than their contract was for just adding 3 light pendant light and 15" of mc and a wall switch in one corner of the tenant space, and I would not be able to make them make all this existing stuff to comply to code anyway. I saw the new mc wiring wasn't supported and told them to fix it. Then I told the tenant that the unused wiring should be taken out and the rest of the existing wiring should be supported and repaired to code for safety, but that I cannot make him do it.
What would you other inspectors do?

 

[Mr. Inspector]

Another building was replacing all their suspended ceiling and adding new lighting with MC wiring. But there was a ton of existing Romex up there too. Since the ceiling is new now, do they need to replace all the existing Romex?

 

[jar546]

I know the NEC says unused wiring is to be removed but this would be a huge undertaking for the electrician which would have been at least 10 times of more work than their contract was for just adding 3 light pendant light and 15" of mc and a wall switch in one corner of the tenant space, and I would not be able to make them make all this existing stuff to comply to code anyway.

What part of the code allows you to make financial decisions and waive requirements based on the cost to the contractor?

 

[steveray]

I know the NEC says unused wiring is to be removed

Which section says this?

 

[Mr. Inspector]

I thought there was but i can't find it. Maybe an older code had it.

 

[steveray]

The code says this: (posted for educational purposes under fair use)

(C) Cables Through Spaces Behind Panels Designed to Allow Access.
Cables or raceway-type wiring methods, installed behind panels designed to allow access shall be supported according to their applicable articles.

What it means:
Imagine you've got a room with a panel on the wall or a ceiling with lift-up tiles – these are designed so you can easily get to the stuff behind or above them, right? The rule here is about how to handle wires and cables in these accessible spaces.

If you've got cables or pipes (raceways) for wires running behind these panels or above these ceilings, you can't just let them hang loose or lay them on the ceiling tiles. That would be like leaving your tools scattered on a workbench – it gets messy and makes it hard to use the space.

Instead, these wires and cables need to be properly supported and secured. This is not just for neatness; it's a safety thing. Imagine trying to access a panel or lift a ceiling tile and having a bunch of wires fall on you – not good. So, these cables should be fixed in place following specific rules (like those in sections 300.11(B) and 300.23 of the code).

The same goes for other types of wiring like low-voltage, optical fiber, broadband, and communications cables. Just because they're not carrying a lot of power doesn't mean you can let them block access. They need to be neatly tucked away and secured, so they don't get in the way when someone needs to reach equipment or wiring behind these panels or above these ceilings.

Sooooo....do you mark which panels need to be removed for access so that the other ones can have wires on them?.....That is, if the suspended ceiling manufacturer allows it to carry the additional weight....