50 Most Common NEC Violations

RICK NAPIER · Apr 12, 2012

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.

jumper · Apr 12, 2012

I got plenty that I see and have seen - no pics.

Do I gotta post sections? Most are really basic.

cowboyjwc · Apr 12, 2012

right now, around here at least:

1) 210.4 (B) & (D)
2) 406.8(B)(1)
3) 300.11(A)(2)
4) 110.12(A)
5) 1006.3 of the UBC

I'm sure I'll think of more later.:happyyes:

ASG · Apr 12, 2012

Panels with transformers below them
Kitchen appliances being hardwired not in line-of-sight from panel with no disconnect switch
Plug-and-cord equipment in hung ceiling

jumper · Apr 12, 2012

Stuff I see the most.

Knock out seals missing.

Overfilled boxes.

Non fan rated boxes.

Switches not grounded.

Improper stapling and securing cables.

Nail plates missing.

Mismatched breakers.

GFCIs missing.

Romex stripped and used in AC discos.

Pull chains in closets with exposed incandescent bulbs.

Working space of panels.

#2 AL SER to sub panels on a 100 amp breaker.

Burial depths in 300.5 shallow.

SABCs tapped for DW/disposal/ or range hood.

Furnace circuit supplying non associated loads.

Romex in underground PVC runs to out buildings.

WH discos missing.

Wrong size/type OCPD for AC unit.

Sump pumps on an extension cord.

Mislabeled panels.

and my favorite:

10/2 NM to a dryer.

jumper · Apr 12, 2012

Loose devices because drywall is cut wrong.

Flying splices in attic.

MWBC neutrals not terminated correctly

277 and 120 switches with no barrier.

Pull box dimensions.

cowboyjwc · Apr 12, 2012

I'll go along with Derek on the securing of cables too. Let me rephrase that, securing of cables and conduits.

rbalex · Apr 12, 2012

From an industrial applications point of view, 250.36(E)&(F) often have problems with both design and installation; especially if the neutral impedance isn't convieniently located (physically)near both the transformer and the first system disconnecting means or, in some cases, first overcurrent device.

texie · Apr 12, 2012

Derek,
That's a list! But true.
About the wire size to the 100 amp sub panel-I'm not sure this will ever get resolved. Problem is, many AHJ's allow this but it never seems to be in writing and you never know which way the wind is blowing that day. I'll be the first to admit that it is not compliant the way the code is now writen.

jumper · Apr 12, 2012

rbalex said:
From an industrial applications point of view, 250.36(E)&(F) often have problems with both design and installation; especially if the neutral impedance isn't convieniently located (physically)near both the transformer and the first system disconnecting means or, in some cases, first overcurrent device.

:?

rbalex · Apr 12, 2012

250.36(E) is the usually the proplem. "The equipment bonding jumper (the connection between the equipment grounding conductors and the grounding impedance) shall be an unspliced conductor run from the first system disconnecting means or overcurrent device to the grounded side of the grounding impedance." It isn't uncommon to simply run the jumper from the grounded side of the grounding impedance to the most convientient grounding electrode whether it is located at first system disconnecting means or overcurrent device or not.

jumper · Apr 12, 2012

rbalex said:
250.36(E) is the usually the proplem. "The equipment bonding jumper (the connection between the equipment grounding conductors and the grounding impedance) shall be an unspliced conductor run from the first system disconnecting means or overcurrent device to the grounded side of the grounding impedance." It isn't uncommon to simply run the jumper from the grounded side of the grounding impedance to the most convientient grounding electrode whether it is located at first system disconnecting means or overcurrent device or not.

I guess I am a bit confused, I thought impedance was a value, not a physical identity. Interesting.

RICK NAPIER · Apr 12, 2012

Pretty good! Your suggestions give me additional ideas while I'm still reading. Please keep them comming.

GerryB · Apr 12, 2012

Why is #2 SER not compliant?

texie · Apr 12, 2012

GerryB said:
Why is #2 SER not compliant?

Because you can't use table 310.15(B)(7) to feed a panel that is not the entire load of the residence.

Strife · Apr 12, 2012

jumper said:
Stuff I see the most.

Knock out seals missing.

Agreed, biggest one I have noticed.

jumper said:
Stuff I see the most.

Overfilled boxes.

Agreed, for the most part.

jumper said:
Non fan rated boxes.

That has to be second best.

jumper said:
Stuff I see the most.
Switches not grounded

I noticed that too, but not that often, as you would imply it.

jumper said:
Nail plates missing.

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.

jumper said:
Stuff I see the most.
Romex stripped and used in AC discos.

What is wrong with that?

jumper said:
#2 AL SER to sub panels on a 100 amp breaker.

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

jumper said:
Romex in underground PVC runs to out buildings.

I assume you mean NON UF rommex? Otherwise I'd still agree, UF cable doesn't need conduit.

jumper said:
Wrong size/type OCPD for AC unit.

Hard to "wrong size" the AC's. between the MCA and MOCP the range is so great, I hardly ever seen one not being either or.

jumper said:
Mislabeled panels.

I agree with this, however, it's a fairy tale. Ain't gonna happen. If all electrical violations will be fixed one day, we'll still have mislabeled panels.

jumper said:
and my favorite:

10/2 NM to a dryer.

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.

GerryB · Apr 12, 2012

texie said:
Because you can't use table 310.15(B)(7) to feed a panel that is not the entire load of the residence.

so it's ok like for a 3-family outside meter/dis to the panel, but strictly a sub-panel it would be 90 amps? 310-16, 75 degrees?

liquidtite · Apr 12, 2012

texie said:
Because you can't use table 310.15(B)(7) to feed a panel that is not the entire load of the residence.

so ser 2awg is good for 90 amps

texie · Apr 12, 2012

GerryB said:
so it's ok like for a 3-family outside meter/dis to the panel, but strictly a sub-panel it would be 90 amps? 310-16, 75 degrees?

Yes, but it may be even worse as you may have to use the 60 degree column depending on code year and if it is in insulation. I note you quoted Table 310.16 (2008) and not 310.15 (2011) which leads me to think you are using 2008.

augie47 · Apr 12, 2012

In a State that allows Homeowners permits, the list is endless:

Most common Residential:

Stapling (Improper or inadequate)
Lack of Nail Plates
Box Fill
Receptacle spacing
Mixed small appliance branch circuits
Too many NM in holes
No inter-system bond termination
Improper overcurrent protection
NM in damp/wet locations

Most Common Commercial:
Violations associated with MWBC
Improper use and identification of grounded and grounding conductors.
Raceway & cable support
Box Fill
110.26

50 Most Common NEC Violations

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