Power to 50 y.o house - main wire question

[bigi]

My house is 50 years old. Currently, I am on an old panel with 100 (?) amp service with no more room to connect anything. Main power wire is underground.

Currently 2 major appliances are - Electric Range with 50 amp breaker and AC with 30 amp breaker.

I'd like to upgrade the panel to accommodate for EV charging that I will plan on doing in the future.

Question: Do I have to upgrade to thicker wire that carries main power to house?
How to confirm that I get 100 amps now and not different?

Thanks.

 

[Thebobo]

My house is 50 years old. Currently, I am on an old panel with 100 (?) amp service with no more room to connect anything. Main power wire is underground.

Currently 2 major appliances are - Electric Range with 50 amp breaker and AC with 30 amp breaker.

I'd like to upgrade the panel to accommodate for EV charging that I will plan on doing in the future.

Question: Do I have to upgrade to thicker wire that carries main power to house?
How to confirm that I get 100 amps now and not different?

Thanks.

Depends on the requirement for you charger and how fast you want to charge some EVs can charge from 20A 120 V outlet, but that takes a long time. But if your talking about fast charge you might need bigger.

 

[NutBucket]

Simple answer is not necessarily. You'd need to get a physically bigger panel (or a sub-panel) to accomodate more circuits but you don't need 200A per se. You'd just have to plan carefully so you don't draw over 100A. Remember, just because the stove is on a 50A circuit doesn't mean it will actually draw 50A. You'd have to use all the burners plus the oven to get close to 50A.

As far as upgrading to 200A service, you'd have to pull new feed lines but I'm not sure exactly who is responsible for that. In my area the utility company is responsible for getting power from the pole to your home (the attachment point on the home anyway). I don't know how that works with underground feeds. I also don't know what happens if the conduit is too small for bigger cables, for example.

But either way even as someone reasonably competent with household wiring I'd contract this job and it won't be cheap. So maybe you could see about getting quotes for both options.

 

[Greenman]

Look at the main breakers to determine amperage. It's not a big deal to add a sub for more breakers.
If the mains are undersized you need to contact your utility company. They'll have a list of requirements for upgrading your service.
You might also consider down grading your requirements rather than upgrading your service. Go to a gas range and dryer instead of electric.

 

[bigi]

^^^ helpful. Thanks.

I am on gas furnace and dryer.

Most likely it'll be a Tesla vehicle(s) of some sort, although it does not matter that much which EV I'll go with. I'd like to dedicate 40-60 Amps at 240V for that purpose alone.

The question about power cable came out due to my plans to cover parts over the cable with concrete to build a patio in my yard. Once I do it, I would not want to change main power cable under it.

 

[NutBucket]

Main power lines should be in conduit. I'd be very surprised if they are not. It's usually a fairly large one...at least 2" I'd say.

 

[thedarkwolf]

Tandem circuit breaker might be the answer here. Allows you to fit two breakers in the spot of one normal breaker and free up some space.

I'm in the same boat and asked a similar question a few months back in the off topic section though I do have plenty of open spots in my breaker panel. Personally whenever I actually need to tackle this problem I will go ahead and run the wiring to support whatever crazy amperage I feel like but set a lower limit like 30 amps at the EVSE. Then if I upgrade to 200 amp service at some point I can just change the setting in the EVSE to the max amps.

I'll probably go with Chevy Volt which only has a 3.3-3.6 kw on board charger depending on the year so I wouldn't need to worry about being able to feed it many amps anyway. That is only around 15 amps at 240v so no problem. The model 3 by comparison can handle up to 11.5 kw in the long range version which is 48 amps.

 

[bigi]

My main panel is old. I had to buy fuses off eBay. After I make sure that the wire to my house will support future needs, I'll replace the panel with additional install of appropriate charger.

 

[thedarkwolf]

ahhh FUSES. Yep time to replace that.

 

[Greenman]

Main power lines should be in conduit. I'd be very surprised if they are not. It's usually a fairly large one...at least 2" I'd say.

I've seen direct burial mains before. Seems like a really bad idea to me.

 

[Red Squirrel]

100 amps is plenty, remember, it's 100 amps at 240 volts, or another way to look at it, two 100 amp 120v legs. 240 volt appliances will of course use a big chunk of that 100, but whatever is left will more than likely be enough to run the rest of the stuff that will be 120v stuff like lights etc. I would avoid perhaps running the dryer (30a), oven at full tilt (40a) and air conditioner (20a) all at same time but even if you do, there's power left over. Ideally though, those loads will never actually be using the full capacity of the breaker they are on, so even if you have all that stuff running at once you'll be ok. I have 100a service myself and I never really have to worry at all about what I run. Though I do want to swap out my panel eventually for one that is physically bigger. I eventually want to run 100a to my garage and 100a to my server room but I have no room to fit such a large conduit on the current panel. I noticed in commercial application they have "splitter" boxes for that which I presume are basically just a big junction box with terminals, but don't think that's something you can really buy at a hardware store.

 

[Micrornd]

I've seen direct burial mains before. Seems like a really bad idea to me.

611 - Call Before You Dig, mandatory by law here.
Seriously, we see the power utilities put in direct bury all the time with conduit along side (for future upgrades) on both residential and commercial.

Here 3 phase lines are always above single phase when both are direct bury (4' minimum bury for either), I've seen single phase direct bury bigger than 6" in some of the fly-in residential subdivisions around here, where all the utilities are underground and in a 12' right of way.
Really crowded and the locaters are allowed a 4' +/- on power lines, so hand locates by contractors (after 611 electronic locates) are just common sense.

 

[Fanatical Meat]

Fuzes = call electrician and replace

 

[monkeydelmagico]

You might also consider down grading your requirements rather than upgrading your service. Go to a gas range and dryer instead of electric.

If you like to cook at all a gas range is great. Plan on spending a few hundred extra for a plumber to do the gas line. Worth every penny.

 

[bigi]

^No.

I actually cook a lot for my family and gas stoves suck balls. Big time.

I really like electric and will never get rid of it.

 

[NutBucket]

I think you've never used a good gas range....

 

[Micrornd]

I think you've never used a good gas range....

Or a convection gas oven....

 

[NutBucket]

Well, supposedly electric ovens are superior in that they hold temperature better. That part sort of makes sense as I'm pretty sure I've not come across a gas oven that does just have a simple open/close valve for the burner whereas electric they can vary the power to the elements quite easily.

 

[bigi]

I think you've never used a good gas range....

May be, but I am sure your login name is proper.

Still, gas burners suck.

 

[Scarpozzi]

I was going to suggest looking at LP or NG for heat/water heating, drying clothes and cooking, but it sounds like you don't want to free up circuits that way. My electric bill was $300 in August of 2010 thanks to the poor efficiency. I switched to a gas/electric HVAC, gas range, tankless gas water heater and my electric bill maxes out at $145 even after I added 500 square feet to my downstairs.

I have 200amp service, got a 100 breaker, 2224 aluminum ser and put a 100amp sub in my attached garage for the 1900 sq ft addition I built.

It may make more sense for you to get a 200 amp breaker panel and make your 100 amp a sub off a new panel if you're doing the work yourself. You would need to move your service line, but could give you more leverage for growth. Otherwise, you may want to consider just hiring an electrician to upgrade your service. A friend of mine had her whole house (1920's) rewired with minimal drywall/plaster damage. It was pretty amazing and only set her back $3500 around 10 years ago. I mention that in case you've identified any electrical design issues your house has that may need to be upgraded too.

 

[BarkingGhostar]

OP, before you do anything in terms of modifying the service entrance electrical cable contact your muni. In my county where the electrical co-op handles all my electrical needs, in order to upgrade said service entrance cable they would need to shut the power off. This isn't a problem, but when they turn it back on they are required to notify the county. Now, my county has seen a tremendous growth in housing and so any home improvements are usually accompanied by electrical upgrades, which the county wants to know to re-evaluate your home to increase property taxes. But, I was once suggested that my reason for upgrade prior to finishing my basement was to run some major electrical woodworking tools (large table saw, drill press, compounded miter saw, etc.). I wish I had that suggestion beforehand because I finished the basement without upgrading the service entrance cable but added a sub-panel to cover all of the new basement circuits (a lot of them). But, for your situation you should have a problem. After contacting the muni then call the electrical provider. Now all service entrance cable is in a conduit. Mine isn't. My service entrance cable is 4/0 Aluminum and I'm not even sure how they would upgrade it. The cost wasn't bad, but the county increase in property taxes would have been +$1500/year.

 

[Red Squirrel]

Wow sounds like something my city would do, any stupid excuse to raise taxes. I would definitely find that out before touching anything. For the costs of the extra taxes it might be cheaper to buy a big 10kw+ generator and run that when you need more power. Bonus is you now have backup power too.

 

[Fanatical Meat]

OP, before you do anything in terms of modifying the service entrance electrical cable contact your muni. In my county where the electrical co-op handles all my electrical needs, in order to upgrade said service entrance cable they would need to shut the power off. This isn't a problem, but when they turn it back on they are required to notify the county. Now, my county has seen a tremendous growth in housing and so any home improvements are usually accompanied by electrical upgrades, which the county wants to know to re-evaluate your home to increase property taxes. But, I was once suggested that my reason for upgrade prior to finishing my basement was to run some major electrical woodworking tools (large table saw, drill press, compounded miter saw, etc.). I wish I had that suggestion beforehand because I finished the basement without upgrading the service entrance cable but added a sub-panel to cover all of the new basement circuits (a lot of them). But, for your situation you should have a problem. After contacting the muni then call the electrical provider. Now all service entrance cable is in a conduit. Mine isn't. My service entrance cable is 4/0 Aluminum and I'm not even sure how they would upgrade it. The cost wasn't bad, but the county increase in property taxes would have been +$1500/year.

Wow sounds like something my city would do, any stupid excuse to raise taxes. I would definitely find that out before touching anything. For the costs of the extra taxes it might be cheaper to buy a big 10kw+ generator and run that when you need more power. Bonus is you now have backup power too.

No surprises
I’m a realtor and some town/cities are sending inspectors & tax appraisers to open houses to check out what’s new regarding value. Fortunately they have to identify themselves and smart agents kick them out.

 

[BarkingGhostar]

One of my neighbors about 16-17 years ago had a deck built off of the master bedroom on the second floor. This also involved replacing a bedroom window with french doors. As the job finished, the county tax assessor came out and inspecting the deck asked if he could go inside. Neighbor told the assessor to f-off as the deck was what was improved on the house, but everyone knew the assessor was being nosy. BTW, of the neighbors that I spoke to that I knew that finished their unfinished basements after the home sale only three out of eighteen did the permit. It wasn't the cost of the permit (2-3% of the material cost to finish), but the post-finish re-assessment. I documented (including pictures) every stage of my basement finishing job with all contractors licensed and bonded in the county--many of them born and raised here, too. I did this more for any future buyer as I would advertise for sale as unfinished, but ask for a price that was for a finished basement.