The gist of this post is that I'm going to install a new 200amp panel that will be located about 5 feet away from the meter as well as a 100amp subpanel which will be installed 40 feet away from the new 200amp panel within the same structure. I'm wondering what size wires I will need for each panel.

I recently moved into a new (yet older 1950s era) home in Minnesota which has overhead electrical wires, and an outdated Stab-Lok 100amp panel that the inspector recommended replacing. My plan is to have Xcel (our local electrical company) bury our electrical wires and upgrade the home to 200amp service (my understanding is that Xcel will deliver 200amp service to the home during the underground conversion work so why not install a 200amp panel).

For the main 200amp panel I'm planning on getting this Eaton 200 Amp Load Center panel.

The new panel will be installed directly next to the existing panel (which is located on an exterior wall about 5 feet away from the installed meter), and all existing circuits will be connected to the new panel or (if the wires for the existing circuits don't reach the breakers and neutral/ground bars of the new panel) I'll install junction boxes to connect the existing wires into their new breakers in the new panel.

On the opposite side of the house I'm building a new attached garage and will remodel the existing kitchen soon, so I'll have need for several new circuits on that side of the house. So, I'm planning on installing a 100amp subpanel on that side of the house after the new 200amp panel is in place and functioning correctly. This is the 100amp panel I'm planning on getting.

So, what size and type of wires will I need to connect the new 200amp panel to the existing meter (5 feet away)?

What size and type of wires will I need to connect the new 100amp subpanel to the 200amp panel (about 40 feet apart)? Since both panels are in the same structure my understanding is that I do not need to add any supplemtary grounding to the subpanel. Is that correct? The 100amp subpanel will be located really close to the water main, so running a bare copper grounding wire from the new 100amp subpanel to the water main pipe wouldn't be tough to do. Should I add it just to be extra safe and grounded?

Is there anything else I should consider as I plan this project?

 

Your questions show that you do not have the necessary skills to do this job safely. I recommend that you purchase the book Wiring Simplified and read it cover to cover and then come back with your questions. Wiring Simplified is usually available at the big box mega-mart homecenters for less than ten dollars. It will usually be found in the electrical aisle and NOT in the books and magazines section. Wiring Simplified has been in continuous print for over fifty years and is updated every three years to coincide with the updating of the National Electrical Code.

Most likely you CANNOT connect a 200 ampere panel to your existing meter. You WILL need an electrical permit from your local Authority Having Jurisdiction (AHJ) and the work will need to be inspected. The local power company also has specific requirements that will need to be observed.

 

IMHO, a panel change is NOT a DIY job, and it's best left to a pro.

Your 100A subpanel, however can be a DIY project. I also recommend picking up a copy of Wiring Simplified and reading it cover-to-cover. It will give you a very good understanding of what you're doing. You can always post here if you have questions, too.

While you're doing the panel change you may want to look into getting a generator (Standby or portable) because this is the best time to install one.

 

I agree with Justin and Furd buy Wiring Simplified. I also agree a panel replacement should never be done by anyone other than a licensed electrician. It is a very dangerous job and best left to professionals. The box too should also have a wire connected to an external ground and not just an internal ground like a copper pipe so make sure your electrician does this for you. As for a sub panel I think you could do that yourself too but you might as well have the electrician do it for you while he is there. The sub panel needs to be properly grounded too.

 

One more vote for the 'wiring simplified' book! I've had mine for 35-40 yrs and while mine doesn't cover GFIs and a few other modern day stuff [because of the age of the book] I still find it useful and refer to it anytime I do electrical work that I'm not sure about.

 

This isn't simply a panel change, it's an entire service replacement. The existing 100 amp meter socket is an overhead socket and cannot be used for a 200 amp service and also must be of the underground type socket. There are some 200 amp sockets approved for either OH or UG service, but the large majority are one or the other. I have never seen a 100 amp socket approved for UG use.

I would advise that you double check to see exactly how much work the power company will do for you and at what charge. Some small rural communities will have their BPW install underground service to a house at no charge, but that is very rare. Generally it is the homeowner's contractor who must install the underground conduit and service lateral to the pole and leave enough length for the POCO crew to take up the pole and connect it once the wiring approval is received from the inspector.

 

I'm not positive but I think our local POCO requires that they install the underground service but they charge an extra fee over whatever they charge for an above ground service. As Joe said - you need to find out what the power company will do and what they expect you to have done.

 

Typically, this type work must be done by a licensed contractor who will take out the appropriate permit, arrange for all inspections and coordinate all parties in order to complete the job with minimal interruprion of your service.