I have an electrician coming out to look at this, but I am curious to see what other have to say. I called Detroit Edison and they were of no help. I did get some information from DTEs website on meter installation requirements, but it doesn't answer all my questions. As stated in the title, I am located in Michigan. I have some electrical experience including industrial wiring an engineering degree in electronics.

Right now my house has 2 200A meter sockets as the previous owner had a business in the pole barn. Right now the pole barn has a 200 amp panel with a 200 amp disconnect/breaker under the meter, and the house has a 100 amp panel. Both panels have their own set of grounding rods with the house also bonded to the pipes, the barn has no pipes. Both meters are located on the house and the pole barn is 200+ feet from the house.

To avoid having the extra service charge for the second meter I am looking to get both buildings put on one meter. I would like to have the option of upgrading the house panel to 200 amps in the future as I will someday be finishing off the basement and adding additional electric appliances. From what I have read it sounds like it is common to run 2 200 amp panels from the 320 amp meter, but I was talking to my electrician the other day and he stated that I may have to run one as a sub panel, say a 200 amp panel in the house and a 100 amp sub panel in the barn, but he was unsure and is looking into it.

I have a DTE approved 320 amp meter socket with dual lugs, would it be code to run both the panels off the meter, keeping the 200 amp disconnect hooked to the barn. Since they are such a distance apart, is it OK that each panel has its own ground? I would like to keep the 200 amp panel in the barn as I plan on setting up my auto/body shop equipment in there (and don't want to buy a panel just to downgrade and replace a good usable panel). Also having the option of upgrading the house to a 200 amp panel in the future would also be desirable.

If you made it this far, thanks for reading it all, I like to make sure I am giving enough information...

A couple of things:

1: You can keep the 200 Amp panel as is and feed from a 100-125 A feeder breaker. That;s usually the max size allowable. It's OK that the 200 A main breaker in the garage is higher. It will act as the required disconnect.

2. Ground rods are required in both locations.

3. You can get meter sockets with two 200 Amp disconnect or even 200/100 in them, but they must be approved by the power company usually. You apparently already have 320 A service. A 400 A box might be able to come with a 200/100 disconnects/breakers and then upgrade a breaker later.

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Originally Posted by op

From what I have read it sounds like it is common to run 2 200 amp panels from the 320 amp meter, but I was talking to my electrician the other day and he stated that I may have to run one as a sub panel,

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A 100 A and a 200 A panel would be OK.

If you switch your Pole Barn to a sub-panel configuration then there are other conditions to be aware of:

First, the feed from the main service panel must be a 4 wire feed.

Second, the panel in the Pole Barn would either have to be switched out or modified to remove the Neutral Bond to the cabinet.

On the sub-panel, Neutral must be isolated from the Grounding System.

There cannot be any equipment grounding conductors connected to the Neutral Bus and likewise, there cannot be any Neutral conductors connected to either the cabinet or the Grounding Bus Bar.

Cross connecting Neutral and Ground conductors or leaving the sub-panel bonded will cause "Objectionable Voltage" to be placed on the entire (both buildings) ground circuit and any bonded metal.

Thanks for the quick replys.

I forgot to mention the feed to the pole barn is only 3 wire. So, I am going to try and avoid making it a sub panel if possible so I do not have to run a 4 wire out there. But, I will do whatever I have to to meet code, even if it means spending a bit more.

If I was to upgrade to a 400 amp service, then I could run 2 200 amp panels with the 320 amp meter? I would imagine a 400 amp service would be a costly upgrade.

The upgrade you wish to make is common and a good way to avoid additional cost. I have done this in commercial applications using 4.0 Triplex, a 320 amp meter-base with the required K4802 kit, and two 200 amp panels. Both the power companies and Fire Marshall's were completely satisfied. 350 MCM is what is the minimum required by the NEC for 400 Amp 10/, based on a 60% load factor. If the load is higher you will need to increase the wire size accordingly. You will need two sources of grounding (The neutral buss and ground rods or plumbing in some cases). I also did the same upgrade to a cattle barn with two 200 amp panels and a distance of about 160 feet. I did not experience any problems but anytime there is a long run of cable I believe in checking for voltage loss. I am waiting to hear if the 4.0 Triplex meets the 2011 NEC for service to meter feeder. I hope this helps and good luck.