There is a workshop, an office and an old house, three separate buildings
setting in a somewhat triangular orientation to each other. All three get
their electricity from a single pole with a 100 amp box.
We're building a new house right beside the old one. (the old one will be
What I want to do is use the existing line (underground) from the 100 amp
box to the old house and connect it to a 200 amp box for the new house. Can
I do this without having to run a new line? I looked at the incoming line
from the electric company pole. It said AWG 4 but it looked very small. The
line going from the box to the old house is multi wire aluminum (about 160
feet) but I can't read anything to tell what it is. It is about the size of
a penny, circumference wise. Also, can I keep the 100 amp box to supply the
workshop and office and have a new 200 amp in the new house?
Thanks for your time.
you spending megabucks on a new home, congrats.
You will need a new 200 amp main service in the new home and feed the
old lines with a breaker sized to the wire to the other now sub
panels, and probably have to upgrade those sub panels too with proper
grounds and new panels.
once you begin changing things upgrading to current code is smart and
may be required by law for excellent safety reasons.
Most likely all the existing stuff is old, time for a overall upgrade
$ well spent!
Note depending on your existing setup you MAY have to upgrade those
outbuildings, for codse compliance, but 100 AMP should serve them
If your building a REALLY NICE home you might want to put the main
service underground for appearance sake. Since the main service line
from the road will need replaced anyway for 200 amp service.
I suggest you call your power company and ask them to take a look
Just to add to what Doug has already said: While the service conductors that
you own, must meet NEC standards, it's common for utility company owned
conductors to be much smaller, so it's not unusual to see thing like 1/0
aluminum connected to a 400 amp residential service
Got ya, I'm not familiar with their rules. Con Edison of NY has their
engineers decide if the size of a lateral is adequate for a service upgrade,
unless of course when the customer owns the lateral, then it has to meet
NEC, but once I connected a 200 amp service to #2 copper and once to #6,
which was in a wooden duct from the street to the house
You need to read more carefully. The poster was referring to the
National Electrical Safety Code (NESC) which is the standard that the
nations utility regulatory bodies use in evaluating the safety of public
electrical utility installations.
"This alternating current stuff is just a fad. It is much too dangerous
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