I have a 1200A existing unmetered main disconnect on the exterior of a building with a gutter can and (3) small services. Owner is building out new units on the far end of the building. We added a 800A ECB directly next to the 1200 and paralleled (3) 3" conduit to a new gutter on the far end. We planned to change the existing 4-barrel lugs to 6-barrel to accommodate the new conductors. However, The existing neutral bus will not accept the new lugs and apparently we cant get a larger replacement. In the past I've used a polaris type tap in disconnects for the neutral. I understand i will have to bond the tap to the encloser. Am I reaching, or will this not pass inspection?
Service Disconnect Neutral Bus Requirements
- Thread starter Sparky718
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electrofelon
Senior Member
- Location
- Cherry Valley NY, Seattle, WA
- Occupation
- Electrician
IIRC you cant use the enclosure as a neutral conductor. You could run a conductor from the existing neutral bus to a new neutral bar, but you would have to size the jumper to the max unbalanced current. Might be best to mount a new neutral bar big enough for everything. Keep in mind the MBJ and GEC connection must land on the same terminal or bus.
jumper
Senior Member
- Location
- 3 Hr 2 Min from Winged Horses
Yep, 200.2(B)
electrofelon
Senior Member
- Location
- Cherry Valley NY, Seattle, WA
- Occupation
- Electrician
Thanks, couldn't remember where that was. I always forget about article 200
jumper
Senior Member
- Location
- 3 Hr 2 Min from Winged Horses
Me too, my first thought was may be 250.24 or something like that but I got lucky and checked 200 first.
Not trying to use the encloser as a neutral... I cant retrofit another neutral bus. I'm asking if I can use a Polaris type multi tap to join all neutral conductors and bond the encloser to the neutral, as required at the first means of disconnect.
jaggedben
Senior Member
- Location
- Northern California
- Occupation
- Solar and Energy Storage Installer
You've added a new service disconnect, right? And it didn't come with a provision for bonding the enclosure to the neutral bus? What am I missing?
You can splice as many neutral conductors as you want with the polaris. I'm less sure about the bond.
You can splice as many neutral conductors as you want with the polaris. I'm less sure about the bond.
electrofelon
Senior Member
- Location
- Cherry Valley NY, Seattle, WA
- Occupation
- Electrician
If I am understanding correctly, you could take all of your neutrals and the gec to 1 Polaris type terminal block, but then you would need to run a bonding jumper sized off 250.66 to the enclosure of the service equipment.
I believe that answers my question. I hope the inspector agrees. Thanks Ethan
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