Main disconnect tapping

Here is a service panel on the outside of the house. It powers a panel inside the house and another panel in the detached garage. It looks like the proper hardware was used. I don’t see this done properly very often so I thought I would share. (As almost always the neutral and grounding conductors at both sub panels were not separated. I rarely find this done properly in my area.


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I only see 3 conductors to each panel. Was this installed prior to 2008? As it is at least 1 panel looks incorrect.

If that 70 amp setup on the left is not a factory assembly then it looks like it a violation. Also the bare copper GEC must land on the neutral bus. As Jim mentioned there should be 4 conductors in those feeders unless this is pre-2008.

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What if that 70 amp disconnect were feeding an outbuilding with its own disconnect, OCPDs and grounding electrode. would it be OK then?

If there was no metallic path to the outbuilding and the feeder was installed under the 2008 or earlier code the 3 wire feeder would have been allowed.

The 3 wire into the house is wrong. It needs to be 4 wire.

As Jim stated there was a time when a 3-wire feeder was permitted but as mentioned this was removed from the NEC in the 2008 code cycle. This is from the 2005 NEC:

250.32(B)(2) Grounded Conductor Where (1) an equipment grounding conductor is not run with
the supply to the building or structure, (2) there are no continuous metallic paths bonded
to the grounding system in each building or structure involved, and (3) ground-fault
protection of equipment has not been installed on the supply side of the feeder(s), the
grounded conductor run with the supply to the building or structure shall be connected to the building or structure disconnecting means and to the grounding electrode(s) and shall
be used for grounding or bonding of equipment, structures, or frames required to be
grounded or bonded. The size of the grounded conductor shall not be smaller than the
larger of either of the following:
(1) That required by 220.61
(2) That required by 250.122

I don’t know when it was installed. Definitely not original to the 1950s house.

Good call on the GEC termination.

I believe it would be ok in the set up you described as long as the detached building is not connected to the primary structure by any conductor such as a metallic water pipe.

See post #5.