I am installing a 3/4 " SLB with 3 # 6 thhn wires and one # 10 thhn EGC. The inside of the SLB is marked " 3 # 6's Maximum" . Does this mean that I have to install a larger SLB to make room for the # 10 ground wire, Or am I allowed to run the ground wire without exceeding the max fill of the SLB ?
3/4 " SLB volume for wiring.
- Thread starter steve61
- Start date
- Location
- New Jersey
- Occupation
- Journeyman Electrician (retired)
If this were a standard LB conduit body then with #6 conductors the fill would be the same as that of the attached raceway. Since it's an SLB I don't believe that you're permitted to exceed the listed conductors on the SLB which would limit you to 3-#6 conductors. Any reason why you're using an SLB over a standard LB?
Eddie702
Licensed Electrician
- Location
- Western Massachusetts
- Occupation
- Electrician
I have upsized LBs before and used bushings
It appears to be a standard LB and that is what is stamped on the outside of the body. I needed three of the same kind so I took three of the same kind off of my parts shelf so they would all look the same. I later found two others also marked LB , but they do not have the same info inside. Inside they are marked " Max wire size # 6 AWG ". On the outside they are marked " 7.3 CU. IN. volume ".
- Location
- New Jersey
- Occupation
- Journeyman Electrician (retired)
That makes sense because #4 AWG and larger must comply with the 6X rule. #6 and smaller do not have to comply with the 6X rule so the limit is the raceway fill attached to the conduit body.
- Location
- Tennessee NEC:2017
- Occupation
- Semi-Retired Electrician
What is a SLB?
- Location
- New Jersey
- Occupation
- Journeyman Electrician (retired)
Service entrance conduit body which is slightly different than a standard LB.
Arlington | Service Entrance SLB Conduit Bodies
With aluminum cover and velumoid gasket. Copper-free aluminum die-cast.
- Location
- Tennessee NEC:2017
- Occupation
- Semi-Retired Electrician
Are they oversized as compared to a regular LB?Service entrance conduit body which is slightly different than a standard LB.
Arlington | Service Entrance SLB Conduit Bodies
With aluminum cover and velumoid gasket. Copper-free aluminum die-cast.www.aifittings.com
I see they have an offset. I'm guessing this is for coming out the top of the meter, or disconnect?
- Location
- New Jersey
- Occupation
- Journeyman Electrician (retired)
It's different in that the "hub" surface (where the threaded portion that would normally go through the wall) is flush with the back of the LB. For a normal LB the "hub" part (for lack of a better word has to go into the wall.
- Location
- Tennessee NEC:2017
- Occupation
- Semi-Retired Electrician
Took a minute, but I finally pictured what you were saying. It would have been easier if the image was flipped up 90 deg.
I am connecting the three LB's to a junction box with chase nipples. This is a 480 VAC circuit with a bonding bushing at the feed disconnect. Can I use chase nipples, or do I have to use a regular nipple with a bonding bushing in the junction box ?
- Location
- New Jersey
- Occupation
- Journeyman Electrician (retired)
If there are concentric or eccentric KO'S you cannot use the chase nipples because you'll need a bonding bushing. There is also the question if using a chase nipple with a conduit body (done all of the time) is even code compliant. I always use a close nipple even when I'm not using a bonding bushing.