50 Most Common NEC Violations

[kwired]

Here one of the ones I listed:

That looks like the wall cavity was not deep enough for most old work boxes. In that case the low volt ring is allowed:happyno:

 

[jeremysterling]

Well now I'm cornfused as this was the way I was remembering the meeting, maybe I'm for getting a detail or two, looks like I have been running 600's for the wrong reasons, but Bob's code references are dead on as far as I can see?

Don't shoot me just yet I'm only human:?

I'm confused as well. Why would it not be OK for a single disconnecting means but OK for 2 to 6 disconnects? Sounds like a discussion for Mike Holt or Steve Arne to comment on.

I'm not MH or SA but I did learn from "steve66" right here on this forum that:

500 KCM wire is rated for 380 Amps. You can normally protect this wire with a 400 amp breaker by using NEC 240.4 (B) (that's the 2005 reference).

However, your can't use this rule for transformer secondary conductors (see 240.21(C) - specifically, the last sentance BEFORE 240.21(C)(1) ). So a transformer that feeds a 400 amp breaker needs 600 KCM wire between the xformer and the breaker.

From what I hear, 500's get spec'd wrong on a lot of drawings.

 

[stickboy1375]

That was an interesting list. Here's one I found out about not long ago that is probably violated a lot. Electric baseboard heat is supposed to be calculated as a continuous load, so 2-8footers, (4000watts) at 240 is 16.67 amps, X 1.25 % is 20.84 amps, now you need # 10's and 30 amp breaker.

Or you can use a heat relay with a low voltage thermostat and still run # 12 or 14 AWG to each heater....

I found that out when a friend (not an electrician), wanted to install a 4000 watt unit heater. He said what size wire should he run and I said # 12. Then we talked again and he said ("How come the booklet says #10?) Maybe I am missing something though because it would be a pain running #10's for a couple of heaters.

Read Article 424

 

[roger]

Wouldn't that be an inspector oversight as well? I mean, I can hide MANY things from an inspector, but kickplates? hard to miss them. Don't take me wrong, I'm not defending the EC who does that here, but I think the inspector is just as resonsible.

Your license (or the company's license you work for) is what's in violation and jeopardy. An inspector may miss something but that does not shift resposibility. However if a lawsiut should happen everybody will most likely be involved.

What is wrong with that?

Could be a couple of issues, if the disconnect is outside you have a wet location and then there is 310.11

What's wrong with this also? If we're talking resi. Besides this might be an old wiring that was code back then.

Because it's feeding a sub-panel and you can not use 310.15(B)(6)

Why is this your favorite?
The old code allowed dryers and ovens to be wired with 3 wires. That's why(even now) they STILL sell 3 wires 30A dryer receptacles, 3 wires dryer cords, 3 wires 50A receptacles and 3 wires oven cords. I seriously doubt anyone's attempting new installations with that configurations, and definitely not that often to be a favorite.

Because even in old code cycles when NM was used for a dryer the third wire had to be insulated. 10/2 NM was never allowed

Roger

 

[texie]

I'm not MH or SA but I did learn from "steve66" right here on this forum that:

500 KCM wire is rated for 380 Amps. You can normally protect this wire with a 400 amp breaker by using NEC 240.4 (B) (that's the 2005 reference).

However, your can't use this rule for transformer secondary conductors (see 240.21(C) - specifically, the last sentance BEFORE 240.21(C)(1) ). So a transformer that feeds a 400 amp breaker needs 600 KCM wire between the xformer and the breaker.

From what I hear, 500's get spec'd wrong on a lot of drawings.

Yes, I would agree 500's would be OK for a single 400 amp service disconnect IF THE CALCULATED LOAD is less than 380 amps. And also concur with the requirements for transformer secondary conductors.
Also, after thinking it through, 230.90 for 1 disco VS 2-6 disco's makes sense.

 

[kwired]

I'm not MH or SA but I did learn from "steve66" right here on this forum that:

500 KCM wire is rated for 380 Amps. You can normally protect this wire with a 400 amp breaker by using NEC 240.4 (B) (that's the 2005 reference).

However, your can't use this rule for transformer secondary conductors (see 240.21(C) - specifically, the last sentance BEFORE 240.21(C)(1) ). So a transformer that feeds a 400 amp breaker needs 600 KCM wire between the xformer and the breaker.

From what I hear, 500's get spec'd wrong on a lot of drawings.

One that can be easily overlooked is paralleling three 500's for 1200 amps, or four for 1600, and so forth. Once you go beyond 800 you must have conductor ampacity greater or equal to overcurrent protection level. I would not put this one in the top 50 list though.

 

[hurk27]

Yes, I would agree 500's would be OK for a single 400 amp service disconnect IF THE CALCULATED LOAD is less than 380 amps. And also concur with the requirements for transformer secondary conductors.
Also, after thinking it through, 230.90 for 1 disco VS 2-6 disco's makes sense.

But that is what Bob pointed out, there is no requirement for calculated load where only a single disconnect is installed, this is the next size up rule and says nothing about calculated load in exception 2 of 230.90 or the direction to the other codes, this is what I missed or miss-understood.

But if we are feeding two or more disconnects there is no restriction on the total rating of the breakers as long as the total calculated load doesn't exceed the rating of the conductors, so it is where we have more then one disconnect that we must use the calculated load to determine the size of the conductors.

 

[texie]

But that is what Bob pointed out, there is no requirement for calculated load where only a single disconnect is installed, this is the next size up rule and says nothing about calculated load in exception 2 of 230.90 or the direction to the other codes, this is what I missed or miss-understood.

But if we are feeding two or more disconnects there is no restriction on the total rating of the breakers as long as the total calculated load doesn't exceed the rating of the conductors, so it is where we have more then one disconnect that we must use the calculated load to determine the size of the conductors.

I agree. It's enough to make your head spin!

 

[resistance]

That looks like the wall cavity was not deep enough for most old work boxes. In that case the low volt ring is allowed:happyno:

The wall was deep enough, yet I?ve never heard of such a thing (using an open low voltage ring to house a high voltage device). You also loose your fire rating, so that can be true! Please post a code section.

 

[resistance]

That looks like the wall cavity was not deep enough for most old work boxes. In that case the low volt ring is allowed:happyno:

The wall was deep enough, yet I?ve never heard of such a thing (using an open low voltage ring to house a high voltage device). You also loose your fire rating, so that can't be true! Please post a code section.

 

[John120/240]

The wall was deep enough, yet I’ve never heard of such a thing (using an open low voltage ring to house a high voltage device). You also loose your fire rating, so that can't be true! Please post a code section.

That looks like the wall cavity was not deep enough for most old work boxes. In that case the low volt ring is allowed:happyno:

I think kwired is being scarcastic, pulling your leg.

 

[acrwc10]

The wall was deep enough, yet I?ve never heard of such a thing (using an open low voltage ring to house a high voltage device). You also loose your fire rating, so that can't be true! Please post a code section.

It falls under the, "if it works, its fine" type of installation we have all found.

 

[Strathead]

I'm not MH or SA but I did learn from "steve66" right here on this forum that:

500 KCM wire is rated for 380 Amps. You can normally protect this wire with a 400 amp breaker by using NEC 240.4 (B) (that's the 2005 reference).

However, your can't use this rule for transformer secondary conductors (see 240.21(C) - specifically, the last sentance BEFORE 240.21(C)(1) ). So a transformer that feeds a 400 amp breaker needs 600 KCM wire between the xformer and the breaker.

From what I hear, 500's get spec'd wrong on a lot of drawings.

That is why I come here. I think I have done this one wrong before.

 

[kwired]

The wall was deep enough, yet I?ve never heard of such a thing (using an open low voltage ring to house a high voltage device). You also loose your fire rating, so that can be true! Please post a code section.

I think kwired is being scarcastic, pulling your leg.

I thought the :happyno: made that somewhat obvious.

It falls under the, "if it works, its fine" type of installation we have all found.

I think those same words are somewhere in Art 90, or maybe it was 110. :happyno:

 

[RICK NAPIER]

Thank you all for your suggestions!

 

[acrwc10]

Thank you all for your suggestions!

You should have asked for pictures of the worst violations we have seen, you could have printed a book. (feel free to copy my picture if you want to use it in class)

A little violation I see all the time, atleast there is a box and cover.



And notice the "neutral" of the K&T stapled to the joist, you should have seen the rest of the attic.

 

[A/A Fuel GTX]

Stuff I see the most.

Romex stripped and used in AC discos.

I don't think it is intent of the Code to disallow this. What about dwellings that have all of the circuits terminating in an exterior panel? This is standard practice in many areas.