How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Inactive Your Own Question
Inactive, Master Electrician
Category: Electrical
Satisfied Customers: 4772
Experience:  Electrical Contractor
Type Your Electrical Question Here...
Inactive is online now
A new question is answered every 9 seconds

I would like to add additional breaker box to 15yo ...

This answer was rated:

I would like to add additional breaker box to 15yo house with 200amp box. I''ve reviewed some options listed on this site. Are their other options? I have oversized meter box on my pole on property which runs to house underground to box. I can access this and could place new box in garage and can run needed wire between. I need breakers for future garage woodworking shop and garden pond and ground source heat pump. This is what I found here: Adding a Second Breaker Box
You can take one of a few paths. You can upgrade your service.. if you go to 200 amp service, for instance, you 100 amp box gets replaced with a much bigger one.. with LOTS of room to grow. This would be the best.. and not necessarily the most expensive option. The power company will bring in a bigger line... and you or an electrician would rewire your house into the new box...
Ok - instead of telling me what you found, tell me what you want to do. What size service you current house has, and what size service you want in the garage. I will need to know if the garage is attached to the home or if its remote (away from the house).... If its remote, how far away is it.
Customer: replied 9 years ago.
Reply to Joseph's Post: Apologies. Would like to add 60 to 100 amps in garage. Garage is choice because of open studs internally at this time. 24 x 24 garage is attached to 16 x 8 mud room attached to 36 x 32 house for 74 overall length. Pole with meter box is approx 45 feet diagonal across crushed stone driveway to nearest (to house) front corner of garage. 200 amp original breaker box is in cellar of house in corner closest to this same mentioned corner of the garage. [so these two points are about 12-15 ft apart, in direct line] Currently, I have four 15 or 20A breakered lines running for 200A box out to garage via cellar and mud room. I have extensive DIY experience with carpentry and plumbing and electrical and architectural design and landscaping. Like your tag line! Yeah, I'm thinking 'big'. Thx.
Customer: replied 9 years ago.
correction - 68 ft house aggregate length 36+8+24
Ok - in this case technically your garage is attached to the home. So your setup for the subpanel will be slightly different. Since you already have a 200amp panel in the basement - here is what I recommend.

Run the new cable across the driveway to the garage. I would take the shortest route to the garage, and mount the panel right where the cable enters the garage. For this you will need to run 2-4 ser aluminum cable. This is rated for 100amps. Now being this will go across part of your driveway, you will need to bury the line 24" deep and put the cable in 2" Sch 80 PVC.

Here is a diagram of how you need to have this wired up:
Inactive and other Electrical Specialists are ready to help you
Customer: replied 9 years ago.
I can see how to do this basically. Does the new box need its own grounding rod or can its ground wire be clamped to the same rod at the base of the pole with meter box? I can see how to and do everything from garage box (new) back to meter box. But meter box has utility seal on meter, although I have my own lock on the box access latchwork. Can I unlatch and access box innards without affecting meter and it's tamper seal? Should I get an electrician to handle this connection aspect with the 'full live electrical' exposure? I have no problem adding wiring into current breaker box and connecting these wires and their breakers, etc, but the meter box is a new animal for me. Thanks for your explanation and detailing, so far. C
You will install a 100amp breaker in your 200amp panel. You wont do anything with the meter - you will leave it. And because this subpanel is in a garage attached to the home, you will install a grounding bar kit in the panel and separate the grounds and neutrals. Your grounding wire will have continuity with the main panels grounding system that way.

But to stress again - you will install a 100amp breaker in the 200amp main panel and run your power to your garage from there.
Customer: replied 9 years ago.
I misunderstood diagram, then. Sorry about that. This secondary off main is what I was thinking and expecting. Instead of the sch 80 grey plastic, can I route appropriate size cable from 100A breaker connect in 200A box through cellar and mud room crawl space and into garage to new 100A box? I can keep distance to 35 actual running feet. Would this cable need to be in a conduit or not? Thx.
Only if you buried the line across the driveway. But running it the way you propose will work just fine without using conduit. Its not required in that case.
Inactive and other Electrical Specialists are ready to help you
Customer: replied 9 years ago.
Thank you very much for your time and expert help.
Not a problem. Good Luck on the project!!!
Customer: replied 9 years ago.
Thanks. C.