I’m looking for input on a situation where my brother had a 400 amp meter installed in his new house a few years ago that was supposed to provide for a 200 amp panel in the house and a 200 amp panel in the detached shop about 50’ away with a single meter fee. Instead the electricians installed two small 200 amp Cutler Hammer BR series panels in the house connecting to the 400 amp Meter and ran a 2” conduit from one of the panels out to the shop location. I was expecting a large 200 amp panel in the house and the shops 2” conduit ran from the meter base. In doing some research it looks like the easiest and least costly solution would be for us to install a BRS225 subpanel feed kit in the panel that the 2” conduit enters and feed the shop panel as a 200 amp subpanel. From what I understand when doing a subpanel versus a panel fed off the meter you need to run a ground wire from the main panel to the subpanel and keep the neutral in the subpanel un-bonded from the subpanel’s ground so all grounding of all circuits is done through the ground wire back to the main panel. If this is correct I need clarification on the grounding.

1. What size ground wire and should it be aluminum or copper? We were going to use aluminum 4/0-4/0-2/0 to feed the subpanel so would we downsize the ground to 3/0 aluminum or what size copper. I’ve found you can get a 4/0-4/0-2/0 service (SER) cable with a ground for about $3.14/ft.

2. I assume we will still install two ground rods at the shop for lighting protection and bond them to the ground in the subpanel that is fed by the main panels ground. Is this correct?

Just as an FYI the house has gas for dryer, stove, and furnace so I'm not sure why two small panels, maybe low cost? We though about removing the two small panels and replacing it with a single large but the 2" conduit from the shop doesn't go into the meter.

Thank you in advance for the help. I've really enjoyed reading through the other questions/answers.

In further research I think I've answered my own questions.

1. The ground to the subpanel can be #4 Aluminum or #6 copper.

2. Since the subpanel is in a detached versus attached location the ground rods are required and will be bonded to the subpanel ground using #8 copper.

In reading through a lot of the other posts I'm surprised how often I see someone say you cannot feed a subpanel more than 125 amps due to the branch breaker size limitation on the main panel. It looks as most panels offer a subpanel feed lug kit which in my case provides a 225 amp subpanel connection that is protected by the main panel's main disconnect breaker. The largest breaker I could purchase would have been 125 amp.

Thanks,

1wheeler1