Lefty0824
Member
- Location
- New Jersey
100 amp main lug sub-panel in a detached garage am I required to drive a ground rod? I pulled an equipment grounding conductor with the phase conductors in the conduit.
detached garage grounding
- Thread starter Lefty0824
- Start date
- Status
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
As Gus said, then separate the neutral and grounds and install the GEC to the ground bar. You also need a main or use the 6 disco rule.
If you only have a MWBC then no rod is necessary.
If you only have a MWBC then no rod is necessary.
- Location
- New Jersey
- Occupation
- Journeyman Electrician
You said main lug (MLO), where's the building disconnecting means or do you have 6 or less CB's?
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
I often use a main lug panel with a DP breaker and a tie down kit. The suppliers don't stock a 60 amp main breaker panel.
Lefty0824
Member
- Location
- New Jersey
there is a 2 pole breaker feeding the MLO panel with 6 breakers and wired as sub-panel isolating the neutrals.
- Location
- New Jersey
- Occupation
- Journeyman Electrician
So the garage has no single disconnect located at the structure just the 6 CB's in the panel at the garage?
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
curt swartz
Electrical Contractor - San Jose, CA
- Location
- San Jose, CA
- Occupation
- Electrical Contractor
Every panel I have seen states that they are suitable for use as service entrance equipment if a main breaker is installed. If that is the case simply having 6 or less branch circuit breakers without a main would not be compliant.
paul
Senior Member
- Location
- Snohomish, WA
Sounds good now drive 2 rods and you're done.
I say drive one ground rod and you're done.
What about 250.56???
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
In a nutshell, the separate building is wired as if it was a service, plus like a sub-panel with a 4-wire feeder.
I disagree. I take it as meaning it;s definitely suitable with the main, and may be without it, if you meet the rules.
Last edited:
T
taylorp
Guest
A supplemental ground rod is only necessary if the single electrode does not have a resistance to ground of 25 ohms or less. 250.56 was deleted in the 2011 code, you should now reference 250.53(A)(2) in the 2011 code.
- Location
- New Jersey
- Occupation
- Journeyman Electrician
And it's replacement section clearly states two rods unless you can meet the new exception.
- Location
- Massachusetts
In my experience, many but not all.
I agree with curts take on this.
If it is suitable for service equipment with no main it will clearly say so. Somewhere I have a picture of the wording but it goes something like this.
'Suitable for service equipment with main breaker kit or no more than six branch breakers installed'
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
I am really curious as to what the difference would be. There are some panels I have seen that will not accept a main breaker kit so I assume - never checked, that it is not suitable for service equipment.
I guess if it is suitable for service with a main what possible can be different with six breaker rule?
I guess if it is suitable for service with a main what possible can be different with six breaker rule?
dana1028
Senior Member
- Location
- San Francisco Bay area
I am really curious as to what the difference would be. There are some panels I have seen that will not accept a main breaker kit so I assume - never checked, that it is not suitable for service equipment.
I guess if it is suitable for service with a main what possible can be different with six breaker rule?
I don't know either - but I have such a panel at my house - in addition to the 6-breaker rule is the restriction that there can be no 110V [line-neutral] loads on any of the 6 breakers [sorry, installed 'bout 8 yrs. ago and the writing in the panel is faded enough I can't photo it].
It's a QO8-16L100D [didn't find any details about it at Schneider].
- Status