50 Most Common NEC Violations

[jeremysterling]

I'm sorry is this a violation? What article number is it a violation of?

Yeah, that's right!

But the OP wanted anecdotal observation and photographs, not the actual article numbers!

Everyday, I open many 4square boxes and see a 250.148 violation. The EGC is not bonded to the box. (With 10 or 12, but to me 12 is OK!)

 

[Little Bill]

Wires not in proper or any connector.

 

[acrwc10]

Wires not in proper or any connector.

View attachment 6775

Ground screw wrapped around a sheet metal screw to a box. very common violation.
Panel cover screws replaced with sheet metal screws.
MWBC phase conductors "on the same phase" (black and red both on phase "A")

 

[iwire]

Panel cover screws replaced with sheet metal screws.

I do that one all the time.

How about if I use these?

 

[stevebea]

I was unable to locate a powerpoint presentation I found on internet on this topic so I have decided to create my own. I am asking all you inspectors, contractors, engineeers or anyone else with an opinion what are the 50 Most Common NEC Violations? These could be plan review or in the field violations. If you have any pictures showing an example even better. Thanks for your help.

Saw this in a church last week...... lordy,lordy!: Extension cord run in CPVC feeding a receptcale. :jawdrop:

 

[hurk27]

If the calculated load on the conductors is less than 381 amps why is this a violation with the 400 amp situation?

In a meeting with the state back in the 90's this came up as people were using the exception 3 to 230.90(A) for where you only have one service main or disconnect, it was explained by the CMP's at the meeting that in order to use this exception you must have one set of SEC's that feed more than one set of mains or disconnects but conductors feeding each main are required to still be sized to its rating as per 230.90(A)

If we look at 230.90(A) it clearly says it:

230.90 Where Required. Each ungrounded service conductor
shall have overload protection.
(A) Ungrounded Conductor. Such protection shall be
provided by an overcurrent device in series with each ungrounded
service conductor that has a rating or setting not
higher than the allowable ampacity of the conductor.

No where in 240 is there an allowance for service conductors to be sized smaller then the OCPD, and 240.2 makes this clear:

Tap Conductors. As used in this article, a tap conductor is
defined as a conductor, other than a service conductor, that
has overcurrent protection ahead of its point of supply that
exceeds the value permitted for similar conductors that are
protected as described elsewhere in 240.4.

Which allows it for taps same as 230.90(A) exception 3 but you are still required to size each tap conductor to the size of the OCPD down stream of the tap.

so if I have a 200 amp service feeding a 200 amp main and a 100 amp out building then yes the service conductors to the split can be 3/0 but the run to the 100 amp main has to be sized for it #3's and the conductors to the 200 amp main will have to be 3/0 as long as the total caculated load doesent exceed the 3/0 service conductors.

But if I only have one main there is no allowance to reduce the size required in 230.90(A)

Maybe this is a wrong interpatation but it's what I got out of that state meeting.

 

[acrwc10]

I do that one all the time.

How about if I use these?

If "you" did it I'd be confident it is safe. I'm talking about the guys that use a 2" sharp pointed ones. :slaphead:

 

[iwire]

If "you" did it I'd be confident it is safe. I'm talking about the guys that use a 2" sharp pointed ones. :slaphead:

For what it is worth that was what Cutler Hammer shipped as cover screws on a 3R panel I installed.

 

[Strathead]

It may or may not be - more details of the installation will make a difference. If you had multiple circuits in a raceway and 10AWG EGC was required for largest overcurrent device protecting conductors in that raceway then you need to run 10 AWG in the raceway. But a 12 AWG EGC pigtail to a device on a 20 amp circuit supplied by 12 AWG conductors is certainly acceptable.

Sorry if I was misunderstood. I was referring to the box pigtail, not the device pigtail, which as we have discussed here in another thread, is not legal.

 

[Strathead]

500 KCMIL for 400 A

500 KCMIL for 400 A

I am confused as heck here. There are a few posts referring to using 500KCMIL on a 400 Amp servicelike this is illegal. This is the size that is 90% of the time specified and used in my area. 310.16 ampacity is 380 amps at 75 degrees. As Kwired pointed out, as long as 230.42 is complied with, (which in most cases I have not seen a new construction calculated that close to maximum) the th 500KCMIL is perfectly fine. IMO. Please comment.

 

[iwire]

I am confused as heck here. There are a few posts referring to using 500KCMIL on a 400 Amp servicelike this is illegal. This is the size that is 90% of the time specified and used in my area. 310.16 ampacity is 380 amps at 75 degrees. As Kwired pointed out, as long as 230.42 is complied with, (which in most cases I have not seen a new construction calculated that close to maximum) the th 500KCMIL is perfectly fine. IMO. Please comment.

I know I am puzzled as well.

230.90(A) Exception 2 seems to directly allow the application of 240.4(B) which allows 500 to be used as you describe.

 

[kwired]

Sorry if I was misunderstood. I was referring to the box pigtail, not the device pigtail, which as we have discussed here in another thread, is not legal.

Why wouldn't the pigtail to the box need sized for largest overcurrent device protecting conductors in that box?

I am confused as heck here. There are a few posts referring to using 500KCMIL on a 400 Amp servicelike this is illegal. This is the size that is 90% of the time specified and used in my area. 310.16 ampacity is 380 amps at 75 degrees. As Kwired pointed out, as long as 230.42 is complied with, (which in most cases I have not seen a new construction calculated that close to maximum) the th 500KCMIL is perfectly fine. IMO. Please comment.

I see same thing a lot with 4/0 aluminum protected by 200 amp OCP, and have installed many times myself - not just dwellings where it is specifically allowed by 310.15(B)(7)

Seems if those installs are incorrect and I was called to correct those installs all I need to do to make them compliant is show a load calculation that is less than the service conductor ampacity, and then somehow tap to another service disconnect - could only be 15 amps and supply one of the loads and now I have multiple service disconnecting means, and service conductors only need to be able to carry calculated load.

 

[RICK NAPIER]

The replies so far have been very helpful. At this rate I will have enough material for a 4 and 8 hour seminar on the topic. I only have to start taking and searching for a lot of pictures.

In answer to the question about what kind of work ie. residential, commercial, industrial etc., well these seminars are offered to electricians of varying backgrounds to meet state CEU requirements. Some of my inclussions will be specific to the bylaws of my state. I wanted to have other opinions so as not to overlook any common issues.

 

[hurk27]

I am confused as heck here. There are a few posts referring to using 500KCMIL on a 400 Amp servicelike this is illegal. This is the size that is 90% of the time specified and used in my area. 310.16 ampacity is 380 amps at 75 degrees. As Kwired pointed out, as long as 230.42 is complied with, (which in most cases I have not seen a new construction calculated that close to maximum) the th 500KCMIL is perfectly fine. IMO. Please comment.

I know I am puzzled as well.

230.90(A) Exception 2 seems to directly allow the application of 240.4(B) which allows 500 to be used as you describe.

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:?

 

[texie]

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.

 

[iwire]

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.

For a singe service disconnecting means 800 amp or less we can round up the next standard size breaker. That is as far oversized we can be. See 230.90(A) Exception 2 and 240.4(B)

With two thru six service diconecting means there is no limit to how oversized the total over current protection could be in realtion to the condutor rating. See 230.90(A) exception 3

 

[iwire]

Well now I'm cornfused as this was the way I was remembering the meeting,

Maybe they were talking about services 801 amps and above as that would put 240.4(B) out of play.

 

[texie]

For a singe service disconnecting means 800 amp or less we can round up the next standard size breaker. That is as far oversized we can be. See 230.90(A) Exception 2 and 240.4(B)

With two thru six service diconecting means there is no limit to how oversized the total over current protection could be in realtion to the condutor rating. See 230.90(A) exception 3

I'm not saying I can't read. (insert smiley face here) I'm saying I don't follow the reasoning behind it.

 

[resistance]

And why is this a violation? they do make UL listed DB rated wire nuts, Ideal calls theirs "Twisters" use them all the time for repairing postlight feeds.

what are Porkies?

This wasn?t a DB rated wire nut, it was a 341 wire connector (Tan). I forgot I need to be detailed around here
[h=1][/h]

 

[resistance]

Here one of the ones I listed: