Upgrading house from 100A to 200A - what should I know?

We're going to be paying somebody to upgrade our electric from 100 to 200 amp system and I was wondering what kinds of things I should ask and what I should know? I'm a little stupid when it comes to electricity, I know basics but no details. I've only had 1 estimate so far and that was around $1500 just to replace the main, not upgrade to 200A.

Background, we've been in our house since nov 2015 so we've only had 1 summer here so far. The house is about 1800 sq ft with 2 zone heat/cool central air and an electric water heater and electric dryer. We have a pole in the front yard with a main on it and another main inside the house (the meter is on the pole in the yard, and the wires run underground to the house).

During the hottest days of summer when trying to run both AC and the dryer the main outside would trip and need to be reset. Nothing ever tripped inside. We had an electrician come look at things and he recommended replacing the entire box inside but said we should be able to keep our 100 amp system. He did replace the breaker outside on the pole and that seemed to fix the problem.

However, a 2nd electrician said over the phone that we should definitely upgrade to a 200 amp system based on just the dual central air units and electric dryer. He's supposed to be coming out to give me an estimate this week or next.

Any opinions and thoughts appreciated, thanks.

 

200 amp service definitely, but how old is the house? If older than 1970, do you know if it's ever had any rewiring done?

 

I've heard a service upgrade could be a $3k job. Never had one done though. Not cheap though.

I'd love to put an A/C in my house but they aren't needed most of the year here in MT.

Most newer homes here are 150-200 amp services without A/C units though.

 

Get a whole house surge protector while you're in there. Cheap insurance.

 

Just make sure it's permitted... a lot of shady "electricians" will upgrade your service but disregard everything beyond the service itself. It matters. On older houses upgrading the service often opens up a can of worms, not that it's a bad thing. Often other upgrades need, or at least should, be done.

 

I would definitely have it done legit with permits and all. The original house was built in 1927 but in 2006 it caught fire and was rebuilt. The former owners who did the rebuild did not take out any permits at all so we don't have any records of exactly what was done.

 

Hoo boy. What state are you in? Did they disclose the no permit fact on the form 17 and you accepted? Just trying to get a visual of all the things that may have to be investigated, I've seen a lot of jerry rigged crap and I've also seen it where everything's just fine.

 

We had an inspection before buying and all was deemed good. We also had an electrician check things out and he said the breaker box was safe but not great and recommended replacing it. It's MA if that makes any difference.

 

I would put a combination panel on the outside of the house and have the power company run the service line underground from the existing pole to your new meter base.

 

Ok, good. I would find a contractor who's conscientious and has (many) great references, then pull the permit and see what happens. Only advice I have other than that is to definitely do the 200 amp, and don't be afraid of the electrician recommending or even requiring (meaning he can't in good conscience continue) other upgrades beyond the service. It's all worth it in the end... having the place burn down because something is inadequate past the service is obviously not an option.

 

With Electric dryer, water heater, and central AC, you need a 200amp service. Although they all will run with 100amps, the surge if they start at the same time may exceed the current service. AC probably has 30amp for the outside compressor, 20amps for the air handler, 30 for the dryer, and the water heater has to be a 30amp. Get several quotes. I'd probably would think they would place a meter socket with a main breaker out on the side of the house and eliminate whatever you currently have on the pole. The box in the house is actually serving as a sub panel box and the grounds are handled differently than if it were a main service box. As part of the upgrade, the building inspector should review the work and verify it is done correctly. They also may inspect the box in the house too.

 

Thanks again for all the thoughts on this. Now I just have to find a guy who isn't too busy to help me. I've called 2 people and both said they'd call me back, that was 3 weeks ago and neither has bothered to show up yet to give me an estimate.

 

So, finally got an estimate and its a bit more than I was hoping for, about $4000 for a full upgrade. I did a load calculation for my house and with all the main electrical components running it's around 70 amps. Would it be possible or even make any sense at all to upgrade to a 200 amp panel and keep the 100amp service, with the thought that we would upgrade the service later on?

 

Just accounting for the "main" components, does not consider that every receptacle in the house is rated for 15 amps. You reallly must think beyond your normal usage and consider your maximum usage at any time.

 

So you think that I'm definitely pushing the limits of 100 amps?

 

Yes. A 100 amp panel (assuming it has a 100 amp main breaker) is only rated for a continuous load of 80 amps. If your large appliances alone have the potential to draw 70 amps for an extended period of time, then I would say you are cutting it close.

 

NO.

In short, your breakers or fuses are protecting the wires from getting hot and melting. You have surges of in-rush current every time you start something with the current spiking for a few moments up to 7 times its running load! 200A service from pole to breaker panel where all the equipment is run from will ensure you don't over load any point of your service and cause a fire.
Quick reference for wire sizes to be used at a minimum. http://www.taylorcountygov.com/pdf/bd/services.pdf\

By the way your price will be high because aluminum wire is not cheap, and pulling it through the ground is a pain in the butt.

 

Well here's another question, I'm getting really upset with both myself for not asking the right questions and the sellers for not disclosing things. My meter is on a pole in the front yard and just today I noticed my bill says "temp pole" so I called the electric company to ask what that meant. They said that usually means it was for new construction and they were confused about why it was there. There hasn't been any new construction since around 2006. So now I'm worried that we're going to be stuck with a bill for fixing this.

I'll get more information Monday when the power company calls me back, the department that's in charge of this was closed when I called.

Anybody ever encountered anything like this? Any info you can give will be helpful.

 

When a house is built, there's typically a temporary drop on a post in the yard near the house. This allows the builder to use power tools without the need for a generator. If it was new construction, im surprised a certificate of occupancy was issued with a temporary drop. Yes, that needs to be fixed. If you're going to 200amps, the line from the telephone pole would need to be changed anyway.

 

Had mine done about 4 years ago. House was built in 1926. The guy we had in did a great job. Took him two days to do minor work I had and then the service change over the next.
Was a little under $5k to have it all done.