We have purchased a home built in 1890 that requires an electric
upgrade. It is currently 100A and we would like to upgrade to at
least 200A. The electric runs from a pole behind our backyard, then
underground for about 100 feet, directly into our basement. We live
in the Boston area. About how much should we plan to spend? Any
thoughts on ranges greatly appreciated. Thanks much.
There are to many variables for anyone here to guess. For instance, where I
work, there are two utility companies, the exact same job would cost $1000
more for one utility company over the other, because of their particular
requirements. Contact some local electricians and get prices
Not to mention that "in the Boston area" may mean
bringing the entire dwelling electrical up to
recent Code level on a service upgrade.
Start with a call to Bldg Dep't or whoever
controls permit applications where you live.
Then there is the meter socket, unless existing is rated 200A. And the
service wire has to be upgraded, which requires larger conduit. And the
underground run may or may not have to be replaced depending on the
existing size and whether owned by the customer or utility. If the
utility replaces it, they may charge the customer.
While you're on the subject, here's my story
I am just getting started on a similar project. My old service is 100A
overhead, my load center is a 24 breaker C-H; the main breakers occupy
two of the 24 positions in the panel.
My oil burner died, and we're going with an electric heat pump and air
handler. The old system included central air, and there is a 220/50A
branch circuit off the old load center to an outside disconnect.
However, the old oil burner ran on a 120/20A breaker, and the new air
handlers require 220/75A. My existing load center cannot provide this.
At first I thought it would require an upgrade to the service and the
load center, which would be pretty difficult since he 100A load center
was shoe horned into a tight spot and the new 200A load center would
be too big to fit in the same spot, not to mention the labor involved
in transferring over the branch circuits.
So as an alternative, I'm uprading the service and the meter pan right
next to the existing one, and adding a fused outdoor 200A disconnect
with two 100A feeds, or whatever they're called. Then running a 100A
branch circuit to where the new air handler will be, with a fusable
service disconnect at that location. The other feed goes to my
existing load center.
My electric company will supply the new meter and pan, as well as
upgrade the lines from the pole to the premises at 'no charge'. By
leaving in the old meter and service, I can wait until the last
possible minute to switch over the existing load center to the new
My questions are:
What do you call the box that will go right after the meter? A fused
outdoor disconnect? A hub?
Does it need to come off the side of the fuse panel as opposed to off
the bottom? I was advised that I wouldn't be permitted to take two
wires dirctly out of the meter, is this true?
Can I eliminate the main breaker from my load center since it will
have a 100A breaker in this new box? What size cable do I use for the
mast, and ofor the branch circuit?
I can locate the box ffeding of the new meter in such a way that the
two feeds exiting will go out the back of the box, is that a plus? (my
existing mast into the meter, and feed to the load center are just a
wire, no conduit.
Hope this helps, and I hope you can help me too.
How do you plan on protecting the 100 amp feeds? You would need to install
circuit breakers or fuses for each feeder. I would install a small
electrical subpanel at the air handler location.
I'd call it a service main disconnect. Depending on the local requirements
you may not need the 200 amp disconnect. For a more compact installation I
would try to put a four circuit (No main) 200 amp (Maybe you will need 225
amp) weatherproof circuit breaker distribution panel directly after the
meter. You can put two 100 amp main circuit breakers in there to protect
your feeders. Make sure that the bus is rated for 100 amp circuits.
Your grounding electrode conductor(s) would now need to be run to the
service main disconnect and this is where the main bonding jumper would now
be located. Your new branch feeders would need to be four conductor and you
would need to remove the main bonding jumper from your existing main panel.
You can usually come out of the side or the bottom of a meter socket. If
you come out of the bottom, the box or trough that you connect to below that
must have a weathertight hub on it. If you wanted to split the wire up you
would need to install a trough directly below the meter and make splices or
taps in there. From the trough you could mount two 100 amp weatherproof
circuit breakers below. You can do this as an alternative to the 200 amp
distribution panel I suggested above and still eliminate the 200 amp main.
The grounding electrode conductor would still need to be relocated.
What size cable do I use for the
200 amp service entrance cable. 4/0-4/0-2/0 for aluminum.
If you are going to be using aluminum for the branches I would go with 1/0.
For copper #2 or #1. These must be four conductor.
It will look neater, but will that be helpful for where you need to run the
cable to? Make sure that you caulk at the top back edge to prevent water
from running behind the box and getting into the wall.
In many/most places you can call the "utility" company and they will tell
you the capacity of the service.
Because the placement of the wires in the first place was a major cost of
underground service, you may find that your already have 200 amps to the
In my case when I wanted to replace an old fuse box with a CB panel, the
electric company said I already had 200 amp to the meter. My electrician
said that the wires to the old box from the meter had 200 amp capacity. It
was just a matter of tearing down the fuse box and putting up the CB panel.
Of course the reality is that if you have been getting my for years and
years with a 100 amp (or less) service, you aren't going to stress the
If anything, "modern" appliances use less power that the equivalent from 30
or more years ago.
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