Just inspected a home with a 200 amp main feeding a 100 amp exterior sub. The exterior sub then solely feeds a 100 amp interior sub. Not sure why they took the power out of the house to just bring it back in but that’s a different subject. The main is grounded solely to the water pipe.
The exterior sub and meter both have separate ground rods.
The interior sub doesn’t appear to be grounded at all.
The main has 3 grounding/grounded bus bars. 2 of them are right next to the ungrounded bus bars and the 3rd is off to the far left. I couldn’t find a bonding screw. It appears the 2 bus bars directly next to the ungrounded bus bars have a bonding jumper in between them. The problem (I think) is that the electrician used the floating bus bar off to the left and the bus bar on the right side of the ungrounded buses to hook up the neutrals and grounds so there is no bond. There are many ungrounded and reversed polarity receptacles throughout the home so I annotated those. I think I also need to address the lack of a bond in the main but I want to make sure I’m correct before reporting it. Anyone see anything different than I’m seeing? I’ll try to attach some pics when I get home. Thanks.
The panel has two neutral, aka grounded, and one grounding bar. They are not interchangeable. Each has a different purpose. The 4 wire feeder should give you a clue as to their purpose.
Ok Jim you’re gonna have to take me to school on this one cause I’m not sure I understand what right is supposed to look like in this situation. How could a bond screw possibly bond the grounded and grounding buses here? Is there a bonding screw there and I’m just missing it?
It looks like the ground for the sub feed is going into the neutral bar on the right. Is that right?
The bond should only occur in the first means of disconnect after the meter. That is called the service. All others should not have a neutral to ground bond.
Any grounding to electrode like rods and water lines should occur at the service.
The feeders to any remote panels should contain a grounding conductor.
Which panel is first after the meter? What you are calling the main panel looks like a remote panel due to the 4 wire feed.
From everything I can see, that is the panel with the 4 wire feed that serves as the service. It’s a mess. It looks like most of the breakers were removed and covered with duct tape.
What’s the reason 3 conductors are used to feed a sub?
A bond screw will go through the neutral bar and into the enclosure of the panel. The ground bar screws into the back of the panel. The metal enclosure effectively provides the function of a jumper.
That main panel is a hack job, I see a ground on the neutral bar, missing wire connector, and if that is the main panel it would be a 3 wire feed. There should be a main disconnect at the meter considering 4 wires. As for the interior panel it should be 4 wires being a subpanel.
, do you have some photo’s to go along with your explanation?
