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M Q

wrote:

I am doing a significant kitchen upgrade and the contractor has
recommended that I upgrade the electrical service to 200amp. I've had
3 electricians out to quote on the work---and received 3 very
different opinions and prices. Two have told me it is not necessary
to upgrade the main power line in the house from the meter to the load
center. The other one says I must.

I currently have 150amp service. The meter and the load center are
separated by about 50-feet. The wiring from the meter to the load
center is 2/0 aluminum. I work for a major residential electrical
equipment maker (starts with a "S" and ends with "iemens")...and our
construction sales people tell me that the latest version of NEC
requires 4/0 aluminum wiring for 200amp service.

What is up with 2 of these contractors telling me it is OK to upgrade
without replacing the existing 2/0 wiring?

Is there some sort of grandfather provision in this situation?

If the price difference wasn't so much it would be a no-brainer. But
at $3,500 vs. $750 it's a lot harder to go with the cadillac solution
simple because it is the cadillac solution....

Does anyone have any guidance on the issues and realities of this
situation?

I guess it depends upon:

1) What is meant by "upgrade ... to 200 amp". If it means putting in
a 200 amp panel, but keeping the 150 amp main breaker, you might be OK,
but I wouldn't call that an upgrade.

2) What your local building inspectors think. You are going to get a permit
for this work and it will get inspected. Right? Take a copy of the bids
that you got to the building inspectors office and see what they think.
Whoever you go with, make sure that the contract is written so that
they are on the hook for making it meet the inspectors demands and your
specs without extra charge. I have seen contractors bid stuff that
wouldn't meet code and then try to ding the customer when additional work
is necessary to pass inspection.

While the required wire size depends slightly on things that you didn't tell us,
like the type of insulation, whether these are single conductors suspended in
air, or bundled together in cable or conduit, etc., there is no way
(from my 1990 version of NEC) that you can get 200 amp through aluminum 2/0.