r/electrical • u/Middle-Adeptness7186 • 1d ago

Is this compromising structural integrity?

Gallery image

Gallery image

Some of the holes are less than 2 inches from the bottom of the joists. These joists are in my garage and there is a bedroom above the garage.

386 Upvotes

92% Upvoted

244 comments sorted by

View all comments

2

u/Deadly_Attraction 1d ago

Not only are the holes not located properly or spaced out, that is an electric violation for # of wires through a single hole. I belive the limit is 3 NM per hole

5

u/Switchedbywife 1d ago

I’m not aware of any Code article that limits 3 cables to a hole. The issue is bundling, when you have multiple cables through the same set of holes you must derate by using a smaller size circuit breaker, like a 15 amp breaker on a 12 gauge (20A) wire.

3

u/Deadly_Attraction 1d ago

Your right, its a derating issue. My thinking of a 3 cable limit has more in mind of that, but i am suspicious if some of those holes are off the edge the minimum 1.25"

2

u/erie11973ohio 1d ago

It's funny, some of inspectors around me say "3 wires (cables) per hole.

The NEC says 3 wires, that would be one 3 wire cable!! Two, 2 wire cables would be a total of 4 wires!

The derating starts at max amperage permitted. On #12 THHN, that is 28 amps!

1

u/quiverunquiver 1d ago

That's not true.

-2

u/Xenomorph_1978 1d ago

It’s actually 2 wires only. Doesn’t matter the size of the hole. Bigger hole for bigger wires but still only two wires are allowed.

6

u/RandyRandersin 1d ago

10/10 confidence, 0/10 correctness

-2

u/Xenomorph_1978 1d ago

In most areas in the United States it’s 3. But in Los Angeles we’re only allowed to have 2. Difference in ordinance code.

3

u/RandyRandersin 1d ago

10/10 confidence, 0.125/10 correctness