Exterior Disconnect means 1 and 2 family dwelling.

Fordean

Senior Member
Location
New Jersey
Occupation
Electrical Contractor
Trying to confirm Got mixed answers from inspectors. Some are unclear on this as well.

Option 1 . The electrical panel. Does not need the separation of neutrals and grounds if the Fire emergency is marked Disconnect means not Service equipment. The ground rods remain in the main breaker panel. And the Grounding electrode.

Option 2. Or Do you install a MLO Panel interior and separate neutrals and grounds and the Main Breaker is exterior.
Ground electrode now needs to be extended by irreversible crimp. ( Finished basements you can't run new ones sometimes. and Ground rods. Are exterior.

Also, You are you allowed to continue to Use service entrance conductors for instance 1/0 for 150 amp and 2/0 for 200 amp. If the main is outside. Do you now have this as the sub panel and the 150 is required the full 2/0 and the 200 required the 3/0 eliminated the deration for service entrance conductors?

Looking at 230.42 I am not seeing the chart where it lets you derate.
 

infinity

Moderator
Staff member
Location
New Jersey
Occupation
Journeyman Electrician
Option 1) Correct. If the EM disconnect on the outside is labeled not service equipment then you can use 3-wires between it and the panel. The panel would not require the EGC's and neutrals to be separated. The GEC'S for the electrodes can land in either the EM disconnect or the service equipment.

2) If the GEC's require extension to the service/EM disconnect I would just use option 1.

The feeder conductors from the service/EM disconnect on the outside to the panel are not required to be larger than the service conductors.
 
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