What would you say are the most common problems or Violations seen by you and what are the Hazards involved. ie what is a 'plain english' explanation for the existance of the specific Code rule(s) being violated. Please put in terms that someone with no electrical knowledge would understand.
2 wires wrapped around a device screw. This is not good because the terminals are only designed to accomodate one wire. I have seen 2 just laid one over the other and also 2 twisted together and then wrapped around. Proper contact is less likely with these methods.
Sub-panels with grounds & neutrals interconnected. This allows neutral current to divide and flow on the grounding conductors and probably the metal piping systems of a building that are connected to the grounding system.
Replacement of 2 wire receptacles with 3-wire, where there is no ground. This provides a false sense of safety. Also, if a ground fault occurs, the ground wire and the metal frame of any 3-wire equipment plugged into the receptacle will become energized, likely hurting or killing someone.
Insufficient conductor lengths in boxes. This makes it difficult to properly install or replace devices.
Conduits & cables not supported properly. When I climb up them, I need enough support.
Overstuffed(OK for a deli sandwich, not an enclosure) boxes. Over heating of enclosures and increased likelihood of a fault occurring while trying to put a cover on, if you even bother to try.
Derating factors not applied, particularly to bundled cables. This causes overheating of the conductors because air can't circulate.
Working clearances not observed. (Guilty, sir). Try squeezing between a steel I beam and a control enclosure to take voltage readings. If your back doesn't come in contact with the grounded column, your big a** will.
[This message has been edited by Redsy (edited 03-06-2002).]
Redsy covered what I feel are the most common, but I will add another one that is really common.
Failure to follow the instructions (this is a listing violation which just might be the #1 violation in WV).
No explanation should be needed, but if explaining to a non-electrician I'd tell them that equipment is tested under a very specific set of conditions. When you do not follow intructions/comply with listing, then you are operating the equipment under a set of conditions that it wasn't tested for. Many times, this isn't a problem, but since you don't know for sure, you are gambling with peoples safety.
Few things are harder to put up with than the annoyance of a good example.
I think redsy covered most of what I find . except the one most common here #1 Failure to pull a permit! or just plain ole tryin to do it without one
Here in mass you have 5 days from when you commence the work to do so .
I alone ( we have 4 Elec Inspectors full time ) hand out close to $500 ( unforunately only $50.00 per permit ) in fines a week on one occasion last week ONE contractor was fined $250.00 alone and someplace inbetween redsy's list I could put Too many Un-Licensed people on the job or NONE at all !
[This message has been edited by HIGHVOLTAGE (edited 03-06-2002).]
Rdesy pretty much covered them but one I see alot is the equipment grounding concuctor cut off flush where the cable is stripped back to. Oh and another one is the 'in mid-air areial splices', the wires twisted together and taped with friction tape the thing about it is the wires are about an 1 1/2" long,usually its a piece of old BX spliced to newer romex and of course the grounding conductors are not connected because of the two different cables. One I see quite a bit is when pvc is used I see alot of white elbows. I guess ignorance is bliss
#1 is < 1-1/4" to framing edge w/o using a nail plate at bored holes and corners and at staples generally above multi-gang boxes... fires from fasteners shorting romex or MC.
#2 is unprotected cables w/in 72" of an attic access where crossing truss bottom chords or joists... occupants place boxes on cables & slide storage items over the cables.
#3 is mis-identified or un-identified circuit breakers on loadcenter directories... occupants work on circuits they believe they have de-energized, or are unable to locate the correct breaker quickly.
#4 is undersizing conductors... numerous ways... leading to fires from overheated devices and equipment
Bill, you also mentioned most common problems [vs. violations], and there are a few "problems" I see daily doing inspections. First is misunderstanding or lack of knowledge regarding the basics, like grounding and overcurrent protection, and not just by homeowners. Thinking that wires shorted by a nail or something will instantly trip or blow the OCPD, or that the instant a wire accidently touches a pipe or gutter, that it will trip or blow the OCPD.
Another common "problem" is lack of respect for the potential of fire and electrocution by homeowners, or the tradesmen types that know just enough to be dangerous, jacks of all trades and masters of none, or even improperly trained electrical apprentices or journeymen, whatever there background. Guess we're all guilty of that at times, working equipment hot, shrugging off some nail plates that are needed at hard to reach locations, not double checking terminations.
And here's one more "problem" probably beyond the scope of your question [but I'm bored tonight]. How about roping multistory office buildings, for instance. This new 2002 rule change allowing NM a few more stories indicates to me that lawyers have taken over the code making process. I can't believe that went through. The only possible explanation I can imagine is cable manufacturers buying votes or threatening lawsuits. Step one, we pushed dirt up over 50% of the bottom story of a 4-story building so we can say it's only a 3-story. Step two, we changed the code to allow a few more stories. Step three for 2005 will probably be to prohibit the use of MC and EMT in buildings over 1 story. I don't know who was on that CMP, but somebody caved.