Question for those knowledgeable in Home Wiring

I'm home shopping. In this weird little town, I'm finding a lot of houses with fuse panels. For insurance/loan reasons, breakers are a necessity.  The question is about Amps.

A lot of what I'm seeing is 100 amp service. I of course plan to run all the usual household appliances, as well as a 220 compressor, 220 welder, and various other things.

Do I need a 200 amp service? 

Will a 200 amp service require a new "drop"?,( or only new breaker box, and the wiring downstream.)

Thanks in advance. I'll google it, too, but GRM knows all.

It probably depends on the specific house. Ie the cables that run from the transformer to the meter may only be rated for 100 amps, and therefore you would need more than just a new meter and panel. 

Or like we just had to do at my house, the lines from the grid to the house were ok, but from the connectors down to the meter on the outside of the house needed to be replaced, and THAT required larger metal conduit to house the wires, and THAT required siding work, etc (dunno how I own cable on the opposite side of the meter, but I do). 

Unfortunately like I said probably case by case.

You might be ok with 100 amp. It's 100 amp at 220v, which is a huge amount of power.

Questions like will you have AC in the house make a big difference when it comes to sizing the panel (I think our account unit requires a dedicated 30 amp 220v circuit).

You're going to want 200 Amp service and while it's possible that you won't need to there's a very high likelihood that you'll need to upgrade the whole drop.

...or do you see an electric car in your future?

APEowner said:

You're going to want 200 Amp service and while it's possible that you won't need to there's a very high likelihood that you'll need to upgrade the whole drop.

This was my gut reaction. Just needed a second opinion. All other responses noted, and appreciated.

Answers:

AC, yep. Gas appliances are common in the area, so maybe gas/electric unit, H2O heater could be either, same with stove, dishwasher, dryer, etc. Gas log furnaces, as well as woodburners are pretty common. So, maybe in a largely gas house, I could get away with a 100 amp service. 

The thing is, I don't want to do anything borderline dangerous/sketchy. Sounds like upgrading it is.

Thanks, one and all.

100A can be made to work even with AC (helps if you've got gas for things like range, dryer and/or furnace), but 200A is definitely better.  Our old house (1400 square feet, in California), had 100A, AC, gas furnace/range, electric dryer.  The 100A limit was never a problem by itself, but I only had 2 15A outlets in the garage, so I couldn't go too nuts with compressors, welders, etc.

I'm not an electrician, but AIUI upgrading the service usually means replacing the main panel, and at that point converting the house from fuses to breaker is probably no additional charge.

Depending on the location of the electrical feed, it might be as easy as anything to leave the 100 amp panel for the house, and take a second drop, with its own meter for the garage.  Depends on your constituency.  I know some places charge higher rates if the meter spins too fast- This is an order of magnitude or two greater, but the stock car track here put in three meters because it was way cheaper than paying the higher rate when all the Musco lights are on.

If you need to replace the panel because fuses, just pony up the dough and fix it right the first time.  The pain of writing the cheque will fade.  The shlepping into the house to reset breakers every time you strike an arc with the welder and the compressor kicks in will get really old really fast.

Home garage guys tend to overestimate the actual electrical requirements - most likely you'll be fine.  Unless you buy a place with electric heat, the actual amp load at any given time will be a lot less than 100 amps, and when you add in even a good sized home use air compressor (say 5hp) and welder (which typically will have something like a 20% duty cycle) you'll still be well under 100.

Obviously you want to be safe, so if you find a house you like that clearly has deficient wiring or a panelboard in bad shape that needs to be replaced, you may as well go for a 200 amp service.  It will only cost a little more.

I've gotten really good at shutting the compressor off when I'm done. Our fridge is on the same circuit. 

We have a 100 amp breaker service, gas heat, gas water heater, electric oven and dryer.  I did the calculations once, and the upshot was yes, 200 amp service would be a very good idea.

If you've got to replace the panel anyway to put in breakers instead of fuses, the difference in time and effort is fairly minimal.  Yes, you will probably have to upgrade the drop (and you'll probably want/have to pay someone to do it).  But in the end, you'll have quite a bit more headroom for a relatively small cost.

I have 100 amp main, 60 amp sub panel in garage.  220v compressor, 220v tig, electric stove and dryer and heat pump.  Smaller house.  I can run compressor or weld while the heat pump and dryer are running.  I can see upgrading to 200 amp main service in the future, but for now it works.  

If you’re installing a new main panel now though, I would see what it would take to just go 200 amps right now.  

Bought our house 42 years ago.  It had 100 amp service and ~10 fuses in the box.  First thing I did was get 200 amp service and a box with ~30 breaker spaces.  After finishing the bathroom remodel last week I am down to 8 empty breaker slots.

Definitely go 200 amp service and a very large box.

I suppose it also depends on the house and how many live there.  The wee 835sf house I bought last year had a new 200A panel put in about 10 years ago.  I have so many empty breaker slots, and about 6 of the breakers in the box are marked "spare" and have no wires run to them.  I have amperage to spare.

My A/C is just a 1.5 ton on a 20A 240v circuit.  Electric stove, electric water heater, gas heat.

I'll ship you some of the extra amperage I have.  What's your address?  

I also live alone, so there is never a time when I'll be running the AC, the stove, and a welder all at once.  Even if I did, 100A would be enough.

But a 1200sf house with four people, a 4-ton AC, and using a plasma cutter while someone is cooking dinner.... 200A.

I would check with the utility company.  A new drop isn't terribly expensive.  You can also play them against each other if you're in a deregulated state.  Call a competing company and say you're thinking of switching to them, but only if they'll give you a 200A drop.

Called the codes inspector guy today, waiting to hear back.

3430 sq ft house for just the girlfriend and I-yeah, I know, wasteful, but its the only thing in our price range with a shop/room for a pool table, etc. It is strangely added on to, and that sq footage looks like they may have included the garage. Going for a second look tomorrow. My gut tells me, if only for resale, 200 amp it is. It probably needs a new HVAC, also. The deck is rotting, horrible, smoked in interior, etc. Just my kind of place. Let's see what the GF says. 

Again, Thanks, one and all. 

Update for any interested parties. 

It is a 200 amp service! I have the girlfriend's approval. The house is quite the project, but it checks more boxes than anything else we've seen in our price range. It is rough, and some demo will be involved. Sold as-is. Off to make a lowball offer.

In reply to wheelsmithy :

It really depends!  I switched my whole house to LED after putting 20 amp circuits in  and upgrading the various appliances to more efficient models.  

Had I known I was going to do that I wouldn’t have wired most of the House with 20 amp service and saved myself a significant amount. Plus wiring with 20 amp wire is a lot harder than 15 amp wire.  

My low voltage transformers are the same way.  All outside wiring is 0 or 00 because it’s DC .  Switching to LED’s for that application made the bulbs 2X as bright while drawing a lot less current! 

Curtis said:

I'll ship you some of the extra amperage I have.  What's your address?  

 

Make sure you use a plastic container, or the electricity will leak out.

My house is 100A service.

Gas water heater and furnace, electric range. Full shop with 220V for plasma cutter, mill, lathe and welder.

The older homes in my area only have 80 (or was it 60) amp service.

How is a fuse panel less safe as far as the insurance company is concerned? Seems like a breaker is more likely to be flipped back on without finding the problem that caused it.

Trans_Maro said:

My house is 100A service.

Gas water heater and furnace, electric range. Full shop with 220V for plasma cutter, mill, lathe and welder.

The older homes in my area only have 80 (or was it 60) amp service.

How is a fuse panel less safe as far as the insurance company is concerned? Seems like a breaker is more likely to be flipped back on without finding the problem that caused it.

The penny in socket trick. 

Keep blowing fuses? Drop a penny in the socket and tighten the blown fuse back in.   Gets the circuit working ( and wires glowing ) until the short starts a fire.  

RE; 

fuses safer than breakers. I really don't know. Frenchy is likely right. I am working on rumors, googling, etc. Maybe fuses are fine. They don't bother me at all, except I don't know if you can still find them. 

In other news, the owners accepted my lowball offer. Next up, home inspection. Projrcted closing date of Oct 8. Build thread to follow. The house needs a lot of work, and I'm Joensing to get at it.

Congratulations!

Streetwiseguy said:

Curtis said:

I'll ship you some of the extra amperage I have.  What's your address?  

 

Make sure you use a plastic container, or the electricity will leak out.

Crap.  I sent it in a semiconductor box.  Depending on the temperature, you might get dead.

Trans_Maro said:

My house is 100A service.

Gas water heater and furnace, electric range. Full shop with 220V for plasma cutter, mill, lathe and welder.

The older homes in my area only have 80 (or was it 60) amp service.

How is a fuse panel less safe as far as the insurance company is concerned? Seems like a breaker is more likely to be flipped back on without finding the problem that caused it.

I was told it has to do with the fuses themselves.  When they blow, they can cause a fire themselves.

A fuse will blow the same as a breaker will throw, so if the problem isn't fixed they will both present the same.

Fuse panels bring back memories. My wife's grandmother had a house built in the 40s with a fuse panel that might have been 8 circuits for the entire house. She LOVED Christmas lights, and my wife and I used to spend 2 weeks decorating her front yard each year. Tens of thousands of lights, way before LED strings. No outside outlets either. Extension cords in the windows. Once it was dark the first night and the lights had run a while I'd go feel all the fuses and swap extension cords around to balance the loads based on how hot the fuses were to the touch.