Cost to Upgrade Electrical Service from 100A to 200A

Status
Not open for further replies.
Joined
Aug 30, 2004
Messages
31,869
Location
CA
I recently purchased a home that was built in 1997 and was a little bit surprised to find the home's electrical service to only be 100A. I would like to add at least one 60A outlet in the garage (NEMA 14-50 240V) for electric vehicle charging. Based on my novice load calculations, I think my current set-up has "tapped out" the 100A service and I will need to upgrade to a 200A service in order to safely accommodate the new 60A outlet. If I am incorrect, please let me know.

Some relevant info: the home has solar panels, electrical a/c (heater is gas), one oven and is about 2500 sq-ft. Location is Northern CA.

How much should I expect to pay for a licensed contractor to upgrade the electrical service from 100A to 200A?

Thank you.

electrical panel1.jpg


electrical panel2.jpg


electrical panel3.jpg
 
In NH about $1500 10 years ago. You may have to pay utility also to upgrade meter.

It appears like you have two 100 AMP circuits in the setup, AC and home.
 
Originally Posted by madRiver
In NH about $1500 10 years ago. You may have to pay utility also to upgrade meter.

It appears like you have two 100 AMP circuits in the setup, AC and home.


I was told by two people that it is the same 100 amp circuit.
 
Anywhere from $1,000 to $3,500 depending on the equipment, electrician, location and other variables. You're in California so you'll probably pay at least double or triple the cost in other areas of the country. Around here it's anywhere from $700 to $1,500.
 
  • Like
Reactions: JC1
My guess is more like $3000 to $4000.

You will need to come up to code which will mean arc-fault breakers for most 15 and 20 amp circuits. Maybe more GFI. New meter pan and outside wiring. The power company may charge you also. Is the wiring to your house overhead? Underground.

Think into the future also. Maybe a heat pump to replace current furnace?

People are going to 300 amp and 400 amp service these days with more things going to electric.

My heat pump has large breakers for the outdoor unit, the indoor unit and a 70 amp one for the booster coil that is mainly used during a defrost of the outdoor unit.
 
Originally Posted by The Critic
Originally Posted by madRiver
In NH about $1500 10 years ago. You may have to pay utility also to upgrade meter.

It appears like you have two 100 AMP circuits in the setup, AC and home.


I was told by two people that it is the same 100 amp circuit.


Turn the 100 amp circuit breakers off and see if the AC still runs.

I would doubt that code would allow a setup where you had to turn off 3 sets of breakers to do a total disconnect of power to the house.
 
Call your power company, a house from 1997 should have 200 A Service,

Do you have any 220 outlets in the house now?
 
The cost will depend on what you want to do.

where are you going to run the dedicated 60 A outlet to?

Just to upgrade the switch panel will be cheap, but to run wires all over the house if needed will be ching ching.
 
Originally Posted by stockrex
Call your power company, a house from 1997 should have 200 A Service,

Do you have any 220 outlets in the house now?

Dryer....that is it.

Originally Posted by stockrex
The cost will depend on what you want to do.

where are you going to run the dedicated 60 A outlet to?

Just to upgrade the switch panel will be cheap, but to run wires all over the house if needed will be ching ching.

60A will be going to the garage.
Originally Posted by Donald
Originally Posted by The Critic
Originally Posted by madRiver
In NH about $1500 10 years ago. You may have to pay utility also to upgrade meter.

It appears like you have two 100 AMP circuits in the setup, AC and home.


I was told by two people that it is the same 100 amp circuit.


Turn the 100 amp circuit breakers off and see if the AC still runs.

I would doubt that code would allow a setup where you had to turn off 3 sets of breakers to do a total disconnect of power to the house.

It's a dual pair for 240V, no? The two 100amp breakers you see are connected with a bar.
 
Last edited:
100 amp service for 2500 square feet house built in 1997 doesn't sound right at all, builder was really cutting corners.
 
That ganged 100A breakers look like one in each leg (the two split legs, phases, whatever you want to call the 180 degree out of phase power). I don't get the ganged 50A and 30A breakers; those look like another 80A service to me (using the same drop), thus making me think (pure guess here) that you have at least 180A service (which probably means 200 rated for the drop). The "Service disconnect" sticker makes me think that these are just that.

Can you pop the cover and see how those AC breakers are wired?

I'm not an electrician but I don't see why, if you truly only had 100A service, that it'd be more than the drop, then a 100A breaker to feed a sub-panel somehow--I'm think you shouldn't need to touch existing wiring, as long as it's all left alone. Let everything new be on a different panel.

I also have to wonder if the cost is going to be much different getting > 200A service. Might as well plan ahead.
 
Yes 100 amp breakers are tied together, thats normal for any 220V breaker.

You have 220V for AC, oven and dryer. Your water heater is gas I assume.

Here are other things I see wrong or odd:

-->Two breakers with tape on them. Always makes me wonder.

-->The breaker on lower left is marked "cooktop" but is 20 amp 110V. What kind of cooking do you have. One unit with over and burners? Or a unit with burners and another unit with oven. A cooktop
will be 220V and more than 20 amp.

-->You have a lot of 2-in-1 breakers. They are a last resort to fit circuits into a crowded box.

-->The breaker under the oven is a single piece with four 20 amp breakers, the middle two tied together. Yet they all appear to be 110V circuits so none should be tied together.

I would run 100 amp into garage and then 60 off that for car charger. Unless the main box will be in the garage.
 
Last edited:
Originally Posted by supton
That ganged 100A breakers look like one in each leg (the two split legs, phases, whatever you want to call the 180 degree out of phase power). I don't get the ganged 50A and 30A breakers; those look like another 80A service to me (using the same drop), thus making me think (pure guess here) that you have at least 180A service (which probably means 200 rated for the drop). The "Service disconnect" sticker makes me think that these are just that.

Can you pop the cover and see how those AC breakers are wired?

I'm not an electrician but I don't see why, if you truly only had 100A service, that it'd be more than the drop, then a 100A breaker to feed a sub-panel somehow--I'm think you shouldn't need to touch existing wiring, as long as it's all left alone. Let everything new be on a different panel.

I also have to wonder if the cost is going to be much different getting > 200A service. Might as well plan ahead.


They legs of 220V can be called a few things, but never phases. A home is always single phase. Only big factories are 3 phase.
 
If the wires leading into the electric meter are too small you'll have to pay the electric company to upgrade those. Then a new meter base and outdoor panel and connect the EV circuit to the outdoor panel. Building inspector may let you leave the indoor stuff alone for now.
 
My AC's breaker is outside, the guy installing it tap from outside the circuit breaker so the fuse box / breaker is not touched at all.

Also did you really check for the load for the right voltage? I don't think you need to run your oven (is it gas or electric? if electric it should be 220V) / dryer / EV charging at 110V. Where is your dryer? If in the garage you can just use the 220V outlet to charge your future EV instead of installing new things. That'll also guarantee you won't use both at the same time.
 
Last edited:
Originally Posted by diyjake
100 amp service for 2500 square feet house built in 1997 doesn't sound right at all, builder was really cutting corners.

You posted almost the exact words I was thinking. I suppose a small house built in '97 might still get 100a service but no way with a 2500 sq ft house !
 
Originally Posted by mk378
If the wires leading into the electric meter are too small you'll have to pay the electric company to upgrade those. Then a new meter base and outdoor panel and connect the EV circuit to the outdoor panel.

I wonder if the power company would have already put in a drop and box rated for 200a since it's probably very common. I believe you can do this and since the breaker box may only be 100a, it will never draw too much for the drop anyway.
 
FWIW, my power company upgraded the meter for no charge when we went from 400 to 600 amp service. The electrician had to bury new conduit I believe but the power company supplied the new wires from the street to the meter (approx 180').
 
Just went through this last year when we upgraded from a 100A Zinsco box to a 200A Square D. It was around $4500 which included repairing the stucco. Out power feed lines are underground with a transformer in the back corner of the backyard of the house behind us directly in line with the box. The longest wait for for SoCal Edison to come out and give their blessing. Fortunately the feed to the house was 200A, shocking since the neighborhood was build in 1967/8 so nothing was needed there.
 
Status
Not open for further replies.
Back
Top