I am in a strip mall unit. Service was recentlly updated (by others) form (1) 200 amp panel to (2) 200 amp panels fed by a 400 amp disc. 150 feeet away at the end of the building. The water main is directly below the panels and has no bond, and a gas line in the attic with no bond. There is a ground rod below the disc. and it is attached to the neutral bar by a #6. The EGC ran to the panel is attached to a ground bar in the disc. seperate from the neutral bar. Now for the questions. Please correct me if I am wrong. Shouldn't the ground bar in the disconnect be attached to the neutral bar by a MBJ. Shouldn't the water main and gas line be attached directly to the neutral bar by a seperate GEC ran direclty and unbroken to the water bond and the gas line. Or... Can the water and gas be attached at each ground point in the panels.
2 panels one 400a disc.
- Thread starter 77naws
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- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
The water needs to be bonded back to the service with a number 2 copper for 400 amps with 2- 200 amp panels. The gas line is bonded thru the EGC of any circuit that serves a gas appliance. Art.250.104(B) next to last sentence
DARUSA
Senior Member
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- New York City
Mbj
Mbj
MBJ should be only on the service disconnect, in this case the 400 amps DS .
Mbj
MBJ should be only on the service disconnect, in this case the 400 amps DS .
Dennis, could you explain the logic behind this section of code, especially the next to last sentence?
I am not Dennis but, it means if a 20 amp circuit fed with #12 is the circuit likely to energize the gas piping, (say it is feeding a water heater) the #12 EGC associated with the circuit has already bonded the piping or can be jumpered to bond it.
There would be no reason to use any other bonding to this piping.
Roger
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
Lucky for you that you are not me.
Thanks for covering.
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
Many inspectors would rightfully not accept a cord and plug for the bond, but a hardwired furnace could be.
IF the 400 amp disconnect is the Service disconnect, then you are correct, there should be a MBJ connecting the grounded and grounding conductors and service disconnect enclosure {250.24(B)}
Often, your premises water line is also bonded from the service disconnect, but in buildings of multiple occupancy with isolated water piping 250.104(A)(2) might come into effect.
As others have mentioned, the gas line is most often considered to be bonded by the branch circuit EGC.
(Don't forget to take building steel and CEE into account also)
Often, your premises water line is also bonded from the service disconnect, but in buildings of multiple occupancy with isolated water piping 250.104(A)(2) might come into effect.
As others have mentioned, the gas line is most often considered to be bonded by the branch circuit EGC.
(Don't forget to take building steel and CEE into account also)
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