I have a question on checking for continuity between the neutral and ground of branch circuits in the main distribution panel. I will describe what happened recently on a new residential project that brought this to my attention.
Our company practice was, on the finish out of the job, for the last thing to be done on the job to be cutting in the panels. In this order on main distribution panel, check bonding jumper, strip all romex sheaths while labeling conductors, connect all grounding conductors, before connecting neutral conductors to the same bar as grounding conductors check for continuity to grounding conductors (each neutral with no neutral connected to bar) then connect neutral conductors once they all checked to be open, then connect ungrounded conductors to breakers. We had been doing this for several years until recently when the following happened.
When the electrical was completed on the job we called for a final electrical inspection. The inspector came out and left a note with the following written on it "neutrols down in panel". The general contractor called to tell me our inspection had failed and read me the note. I having never heard that terminology before called the inspector to ask what he meant by "neutrols down in panel". He told me in a not so friendly way that we should have checked for continuity between neutral and ground before calling for a final inspection and when he finds continuity he stops his inspection and will not inspect any further until it is clear. I explained to him our practice and how when we checked they were all open. He angrily told me they were not. I went back to the job site disconnected all the neutral conductors at one time from the neutral/ground bar, checked each one all showing to be open to ground, then reconnected all neutral conductors. At this point I call the inspector back. Politely tried to tell him I could not find any neutral conductors with continuity to ground. He angrily told me there was. I was mad but keep my cool, and told him that I did not read continuity to ground on any neutral conductors. He simply said "OK". I called and scheduled a reinspection for the next day. I wanted to be at the job site when he was but I missed him. He had left a note that said "neutrols down stop inspection". I immediately called him. He was very short with me in telling me that he had already told me once that he would not inspect any further until I fixed the neutral continuity to ground. I told him again that I had checked and it showed to be open. I asked him which one had he checked. He said he did not know but it had to be fixed before he would even look at anything else. We hung up and I opened the panel cover. One of the white neutral conductors had a small red ink dot on it. I removed that one from the bar checked with my meter to ground and sure enough continuity to ground.
I then traced back that neutral to a 3 gang switch box with two circuits in it. With the neutrals from both circuits wire nutted together. I then realized he was taking one neutral at a time from under a terminal checking it then reconnecting it before checking the next. Because those two branch circuit neutrals were together he was reading through back to the panel where the neutral and ground are bonded. Where as I was disconnecting all branch circuit neutrals then checking one at a time to ground before reconnecting any back. I separated the neutrals from the two circuits.
To fix the flaw in our old method we now check in this order on main distribution panel, check bonding jumper, strip all romex sheaths while labeling conductors, connect all grounding conductors, connect neutral conductors to the same bar as grounding conductors while checking for continuity to grounding conductors one at a time before putting neutral conductor under terminal, once they all checked to be open connect ungrounded conductors to breakers.
Finally my question is. Which is a better way of checking? and Do you think this is good practice for inspector to take conductors loose? I do not know of another way in which you would have found this issue.(In this case the wires from all this were almost cut into at the terminals from all the tightening and loosening. Which by the way we cut all the ends off and fixed after the inspector disconnected for the 3rd time.)
Sorry for the long post hope someone has the patience to read and reply. Thanks.
[This message has been edited by Electricrulez247 (edited 07-07-2004).]
247: What you described must be a local thing in your area. We do not check continuity on any installations, nor do we disconnect any terminations. That's the responsibility of the Lic EC on the job.
At final (resi) the power must be on in the structure, and all items must be connected and energized; bulbs must be in all fixtures, panel cover must be "on" and directory in place. Yes, we do open the panel & check cb/conductors, neutral/ground bond, etc.
Your system sounds quite thorough, and it is a very good practice for you/your co to perform.
As to the two neutrals from two circuits being spliced together at the switch box, that is not a good practice for many reasons. (Backfeed, etc)
BTW, welcome to the Forum, and ECN
[This message has been edited by HotLine1 (edited 07-07-2004).]
#88704 - 07/07/0406:10 PMRe: Check for neutral to ground
Indeed, your checking is thorough and over here in England we also carry out neutral-to-ground tests on new circuits (made somewhat easier by the fact that we always use separate neutral and ground bars in panels).
But as John mentioned, the fact that you have neutrals cross-connected means that there is more than one path for current and thus I would imagine that the NEC rules on parallel conductors would come into play.
#88705 - 07/07/0409:27 PMRe: Check for neutral to ground
Thanks for the replies. I did edit my post. I wanted to get across the problem with what I had done as well as question the inspector disconnecting all these neutrals and reconnecting. I question the damage done to the condutor. Not to mention messing up my neat panel.
By the way this is a 7000+ sqft house you can imagine the number of neutral connections.
#88706 - 07/07/0409:38 PMRe: Check for neutral to ground
Thanks for reply. Thought about changing to use separate bars. Then removing bonding jumper and checking for continuity. But with out checking each neutral conductor separate (while others are bonded to ground)you would still have not found the two neutrals together.
Thanks for that info makes me think I may start doing that.
#88707 - 07/07/0411:22 PMRe: Check for neutral to ground
Let me get this straight... You're Inspector, pulls neutrals HISSELF! Without you there, and expects you to be liable for his reinstallation, if you had passed?
Now, the purpose of this test is what? I don't think this test he's got going is totally usefull, or nessesary. Granted he found two neutrals tried together elsewhere, but least it was two, as opposed to one for multiple circuits. Is there a test for that too? Is he looking for grounds used as neutrals?
Mark Heller "Well - I oughta....." -Jackie Gleason
#88708 - 07/09/0412:13 PMRe: Check for neutral to ground
I just as shocked as Mark here! An inspector unscrewing anything beyond a deadfront is unheard of around here... If an inspector here wants something tested out, he'll write it up to call him to watch US or someone we hire perform the testing he wants... I'd love to hear another inspectors opinion on this...
Ryan J, Joe T, Bob (iwire)... You're up!
#88709 - 07/09/0401:49 PMRe: Check for neutral to ground
randy, no way in hell would i take a screwdriver to anything but dead front screws.this guy has a few screws loose imho.i always have the electrician or other do the deed.if you touch it or break it you own it,plain and simple.
#88710 - 07/09/0405:59 PMRe: Check for neutral to ground