grounding connection

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mjc

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Had a situation the other day (swimming pool) where I connected a #8 copper solid bonding wire to a #8 thhn green grounding conductor under the SAME mechanical lug. I installed this lug with a bonding screw to the metal can of a 60a/250v 2pole safety switch. The AHJ didn't knock down the instalation but said that the two conductors should not be under the same screw. :roll:
I think that a ground fault would have to depend on continuity from wire to wire through the lugs. The better of the two connections would be a direct wire to wire connection under one lug. Please advise and or site an NEC referance that promotes or prohibits this.

Thanks, Mike -- Michigan
 
Re: grounding connection

From 110.14(A), "Terminals for more than one conductor and terminals used to connect aluminum shall be so identified."

In service equipment, the terminal bars are listed for two and sometimes three grounding conductors. If your single lug is not listed for multiple wires, you can't do it and the inspector is correct. :D
 
Re: grounding connection

In a disconnect switch or panelboard you are supposed to use a REAL ground bar - not 2 lugs joined with a nut and bolt.

For an older disconnect switch where there are only 2 ground wires to connect I would accept a single lug that has 2 openings and 2 setscrews. An equipment ground bar is essentially a "lug" that accepts 3 or more wires. Some of the older disconnects do not have a place where a ground bar can be installed if it requires 2 mounting screws.
 
Re: grounding connection

Mike, for some reason I heard that same thing when I started, but there is no distinction between current carrying and grounding conductors regarding terminations in the NEC. The same rules apply. :)

I wonder if there is an older code, or if it's okay in mobile homes, or something. Weird that it would be "common knowledge" in CO and MI.
 
Re: grounding connection

I have never seen a lug listed for more than one grounded conductor,but as stated there are many listed for more than one grounding conductors.Either way they have to be listed for the particular installation ;)
 
Re: grounding connection

allenwayne,
I have never seen a lug listed for more than one grounded conductor,but as stated there are many listed for more than one grounding conductors.
Click to expand...
?? I've never seen a lug(wire terminal or connector) where the number of permitted conductors was dependant upon its use. I have seen that in the listing for the neutral/grounding bar in service equipment.
Don
 
Re: grounding connection

there are some set screw lugs that are listed for more than one conductor. The only way to know is to check the catalog. The type of lug I am referring to is similar to an Ilsoc TA-35
 
Re: grounding connection

The first couple of comments were talkimg about the connection of grounding conductors. In Art.110.14(A) States that the lugs used for more than one conductor shall be so Identified. The latter comments about grounded conductors would also fall under this Art. or under Art.408.21 but this is panel boards.
 
Re: grounding connection

i was refering to circuit breaker panels,The grounded conductors can only have 1 per terminal but some like C/H can have 3 up to # 10 grounding conductors under 1 set screw as long as all conductors are the same size ;)
 
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