Originally Posted By: Greg Fretwell This post was automatically imported from our archived forum.
It will get back to the listing of the lug and if this lug is part of the panelboard, the listing of the panelboard. Can’t you find a lug on the neutral bus that can hold this bonding jumper? Bus lugs usually hold up to #4. (the typical bonding jumper for 200a)
They also make “twofer” adapters that use 2 smaller holes for a larger conductor.
Originally Posted By: Russell Frame This post was automatically imported from our archived forum.
There is a large lug on the neutral bus, right next to the main feed…no problem there. It’s the ground bus that’s the problem. Only one large lug, it’s a huge lug so there’s lots of room (like 2/0 size).
Oh well not a big deal, I can pick up another lug....just stuck it in there for now and got to thinking about it.
Originally Posted By: Greg Fretwell This post was automatically imported from our archived forum.
I am not sure I understand the problem.
The neutral from the service goes in the big lug on the neutral lug.
Is this the jumper between the neutral bus and the ground bus that you are installing? If so it should fit in one of the smaller neutral bus holes it it is #4.
Legally the green screw and the attaching screws from the ground bus to the can is your jumper but I like a piece of wire there too.
Originally Posted By: Russell Frame This post was automatically imported from our archived forum.
Yeah the neutral from the service is in the large neutral lug, but there is another smaller lug right next to the service lug (which I assume is for bonding).
I dont understand how the can can be your bonding connection? What if this weren't being used as service equipment...how would you 'turn off' bonding?
I'll take a picture this morning so you can see what I've been trying to describe.
Originally Posted By: Greg Fretwell This post was automatically imported from our archived forum.
The neutral bus should not be permanently bonded to the can. There should be a green screw in a bag. If this is a sub you should be installing a supplimental grounding bus for your EGCs. Personally I prefer a hard wire grounding jumper when you installl a supplimental grounding bus in the “main” for a bonding jumper but the code allows the screw alone.
Originally Posted By: jpeck This post was automatically imported from our archived forum.
If the service disconnect enclosure is ‘Rated for Service Equipment ONLY’, then the neutral terminal bar IS permanently attached to the enclosure (ground).
If it is 'Rated for Service Equipment' (no "Only"), then the neutral terminal bar (neutral bus) is isolated from ground. When used as 'Service Equipment', the neutral terminal bar MUST be bonded to the enclosure (ground). When not used as 'Service Equipment', the neutral is left isolated from ground.
Neutrals MAY NOT BE multiple tapped. Only one conductor is allowed per neutral terminal. Equipment ground terminals, on the other hand, are frequently (but not always) rated for 2 conductors of the same size.
Everything is spelled out in the label on the enclosure.
Originally Posted By: Russell Frame This post was automatically imported from our archived forum.
Yes, that’s what I’m talking about. I’m not double tapping the neutral, I’m double tapping the ground lug. I couldn’t find anything on the labels to specify what the ground lug is rated for…but I’ll look again.
Originally Posted By: mmason This post was automatically imported from our archived forum.
Hello
I personally would never recommend double tapping anything. You run the risk that you might loose, solid electrical conduction. 
The only instance where I feel double tapping is Ok is when you have an approved connection device specifically made for that purpose. Thier is all kinds of great ways to connect wires together. The best in my opinion are the connectors that have a bolt on them that you can really crank down hard on the wires. But not too hard.
Then their is many options for insulating them from very thick insulating tape to plastic or composite cover to insulate. When in doubt alwyas ask a certified electrician that knows his stuff. I think the commercial electricians are a little better qualified than a residential electrician
-- Michael J. Mason
Mason Home Inspection
California Capitol NACHI Chapter President
Originally Posted By: jfarsetta This post was automatically imported from our archived forum.
Jerry,
I do believe that some panelboard manufacturers okay double lugs for neytrals under the same screw. I dont particularly like to see it, but was recently corrected that the bus bar and screws were, indeed, rated for it. It depends on what the tag says the panel is rated for.
-- Joe Farsetta
Illigitimi Non Carborundum
"Dont let the bastards grind you down..."
Originally Posted By: Bob Badger This post was automatically imported from our archived forum.
Joe that is true you may still find panels that have neutral bars rated for more than one terminal.
However there is a section in the NEC (408.21) that prevents doing this.
I do not know when that section went in, it may be new for the 2002 NEC and of course panels installed before that section was put in are not an issue.
Anything new can not have more than one neutral per conductor. Well there is one exception for parallel conductors. The wires would be 1/0 or larger and the lug would have to be listed for two conductors.
Originally Posted By: Bob Badger This post was automatically imported from our archived forum.
Joe are they under the 2002 NEC?
Here is the section
2002 NEC
Quote:
408.21 Grounded Conductor Terminations.
Each grounded conductor shall terminate within the panelboard in an individual terminal that is not also used for another conductor.
Exception: Grounded conductors of circuits with parallel conductors shall be permitted to terminate in a single terminal if the terminal is identified for connection of more than one conductor.
It has worked OK for years, but the rules have changed.
But if the AHJ is OK with it, is it still worth calling out? 
Originally Posted By: Ryan Jackson This post was automatically imported from our archived forum.
Bob 408.21 is new for the 2002, but it was put in to match the UL standard on grounded conductor terminals which didn’t allow more than one nuetral per terminal.
Originally Posted By: jtedesco This post was automatically imported from our archived forum.
The exception is referring to the two white wires, they are the grounded conductors run in parallel, and if that lug was designed for more than one, that is what is considered.
