Intent: This new section should ensure that grounded (neutral) conductors terminate within the panelboard to an individual terminal. This has been a UL requirement (UL Std. 67 – Panelboard Standard) for some time, and the addition to the NEC is intended to bring this information to the installers. Technically, this is covered by 110.3(B), which requires all equipment to be installed in accordance with the manufacturer’s installation instructions and markings, but nobody knew it existed. UL Std. 67 (Panelboard Standard) permits up to three 10 AWG equipment grounding conductors to terminate on a single terminal, if the terminal is marked for this purpose.
The intent of this requirement is to ensure that the grounded (neutral) conductor of a multiwire branch circuit is not momentarily disconnected, which could result in the destruction of electrical equipment and fires from overvoltage.
My Comments - As we have talked many times regarding this and have posted things as well, it is always important to know exactly where the reason for reporting it comes from. This is posted courtesy of Mike Holt Enterprises
nice post Paul. good to know. what if this info is not availible in the panel, or on the cover door. do we assume it’s o.k. or not o.k.?? when in dought, call it out?
it is never ok for Neutrals to be double lugged regardless of the panel ledger. As for the grounds it is a common practice to place (2) grounds of the same AWG per terminal.
Keep an eye out for someone placing (2) grounds under a terminal that are different size AWG’s which is most certainly a thing to call out.
The main issue here really is the doubling up of the neutrals or mixing the neutrals with a EGC at the same terminal, Most every one calls this out anyway I just wanted to post a image to help seal it in the memory as well as giving a reference to better understand it.
No problem my brother…my own brother who is a TOP NOTCH electrical contractor about 60 miles from my electrical contracting business…has been putting Neutrals and Grounds under the same lug for years…and the local AHJ never called it out.
So when I came over to speak at their local Apprentice program and the local AHJ happen to sit in on it…guess what…ALOT of panels were turned down in the coming weeks after…lol…now my brother does it the right way…lol…
With everything electrical contractors have to learn and keep up with, things in the UL can be laxed on…thankfully we have people like Joe T who are spreading the word on it more and more because even I don’t carry around a UL White Book…may start to however…thehehhe…anyway I am glad the NEC 2002 addressed it.
I just wanted to give it to ya in Laymans Terms to better understand it…Mike Holt’s books do a good job at breaking it down for you.
I’m sure i speak for many of us when i say, we realy appreciate you, Jeff, Joe, and ALL the other electricians who help us out with the most difficult, and “ruly” systems in a home. i’ve learned more from you folks than any of the 3 HI corrispondences i’ve done, any of my residential or military training in this feild. Thanx again…Jay.
In nature it is a Safety Issue as well…while the standard has been around for many years…in my opinion their is a safety aspect here as well that should be addressed.
Many electricians did this for years as much of a point to twist them together under the same terminal…however it has been a violation of Standard 67 for quite some time.
Twisting together MAY remove the grounded and Equipment Grounding Conductor…BUT does not mean the Non-Grounded conductor is not present and ON and their is a possible other issues…which could be a issue if removed even together.
I personally just dont like to see grounded conductors DOUBLED up on anything…I also find that the terminals get LOOSE faster in that manner as well versus individual terminations.
it is never ok for Neutrals to be double lugged regardless of the panel ledger. As for the grounds it is a common practice to place (2) grounds of the same AWG per terminal.
Keep an eye out for someone placing (2) grounds under a terminal that are different size AWG’s which is most certainly a thing to call out.
The main issue here really is the doubling up of the neutrals or mixing the neutrals with a EGC at the same terminal, Most every one calls this out anyway I just wanted to post a image to help seal it in the memory as well as giving a reference to better understand it.
Paul, thanks for the clarification. Based on your comment “The main issue here really is the doubling up of the neutrals or mixing the neutrals with a EGC at the same terminal”, here’s a photo of a mix.
There is another similar violation people seem to ignore. In the main panel you have a neutral bus bar, connected to the grounded service conductor or connected to that bus bar with the factory strap but you can also have other auxillary bus bars screwed directly to the enclosure. Those bus bars are ONLY for the grounding conductors. If you connect a neutral to one of these it is a 250.6 violation since you are sending branch circuit current through the main bonding jumper. Even in the main panel where the service disconnect resides, all ground busses are not the same.
