200 vs 300 amp service

[bashr52]

Hi All,

The framing on our new house is nearing completion, and we just made the call to the local utility to see about getting the power run and meter installed. The house is just over 1800 square feet, with a 1200 square foot pole bar being built next to it.

The garage will be attic trussed, with room for future apartment/in-law suite expansion later on. As far as immediate loads in the garage: compressor (240), welders (120 and 240), 2 post lift, mill (240), lathe, grinders, lights, etc. Dedicated heat/A/C system for the garage is on the future plans list, along with finishing the upstairs.

The original plan was a 200 Amp service to the house, with a 100 Amp sub to the garage. Looking at the list of immediate and future garage loads however, I don't think 100 amp will be enough. Biggest loads we will have at the house will be heat pump/ A/C system, dishwasher, and the dyer (maybe). Oven and tankless water heater will be propane fired, may run a line for gas dryer as well.

I need to talk to the electrician once they start, but my new thought is perhaps a 300/320 amp service to the house, with a 200 amp sub to the garage.

It is worth a 300 amp upgrade, or is going all the way to 400 the more acceptable approach?

 

[sberry]

100 will be plenty in the garage. If I can do it with 200A service I do, so much simpler with less equipment and if you ever want to make emergency power way easier.
It isn't how much stuff you own but how much is used at one time. If you have gas hot water and gas dryer 200 will run this easy, 100 would run the whole place.

 

[alfredeneuman]

I need to talk to the electrician once they start, but my new thought is perhaps a 300/320 amp service to the house, with a 200 amp sub to the garage.

It is worth a 300 amp upgrade, or is going all the way to 400 the more acceptable approach?

There is no such thing as a 300 amp service.
400 amp services are also known as 400A/320A continuous.

 

[wyliesdiesels]

Backup. the first thing you should be doing or shouldve done is a load calc.

Have you done one? Or did your electrician do one?

Almost all PoCos require one on new builds.

This is the only way to properly size a service.

 

[sberry]

Wylie is right. No reason if gas is in use already not to run it to a dryer too. All gas is great in power outage. The AC and electric heat is the only real load, lights have went to all led and can have every one on in the place with room to spare on 15A anymore. Garage use is so intermittent that it's almost not a factor.
If you have all gas major appliances room to spare on 100,,, with 200 you have 2x headroom.
One of the reasons they want load Calc anymore is to size the ******. Everyone figures to be freaking Edison and thinks they use more power than anyone on the block,, all electric house minus heaters is about 85 peak.

 

[astroracer]

You will never use the full 100 amps out in the shop unless you are running everything all at the same time. Never happen in a one man shop.
I have all of the equipment you mentioned above and then some and have never popped a breaker either in the shop panel our the house panel. That's 35 years of use out of a 200 amp service on the house with 100 pulled to the shop.
200 amp panel in the house will be fine.
Mark

 

[Diesel Dan]

Almost all PoCos require one on new builds.

Being that OP is in NY which is most likely closer to CA regs than we are you are most likely correct. However our POCO didn't require load calcs.

I went with the 320/400 feed, 200 panel in living quarters and another 200 in attached shop. House is all electric, 3 on demand water heaters, 2 mini splits, ERV, car lift, weld plugs, RV hookup etc and slots fill up fast!

:Edit:
With our son visiting and his RV hooked up I do know of times when all 3 water heaters were running, both mini splits in heat mode, dishwasher running, electric heat in RV etc.

 

[Matt Matt]

I would go with your original guess seeing as you are going to have LP. 200 amp service with 100 A feeding the subpanel for the shop.

Without knowing the size of the shop and how much lighting you will need and if you have a big air compressor and/or welder, or any electrical heat for the shop, it is a little bit hard to determine. A load calculation wouldn’t take too long.

Am I safe to assume that this will be a hobby shop?

 

[bashr52]

Thanks all. I'm sure the house loads will be minimal with all gas appliances. As I said we are just in the framing stages of the house now, we called the local utility yesterday to see about getting a feed from the transformer to the house, so we have yet to meet with the electrician about actually doing the house install.

I should have updated my profile, I am no longer in NY, but on the eastern shore of VA. Good to hear 100 amps should be good for the loads I'm looking at, my biggest fear would be A/C is running in the garage while I'm running the big welder and the compressor kicks on our something. That has the potential to spike over 100 amps during startup.

Yes it will be a hobby shop, will mostly just house/work on my boat and play car, and used for maintenance on the fleet until I take on another inevitable restoration project...

 

[mike93lx]

My house, with 2 fridges, a freezer, electric dryer, 2 ton mini split, well, and all of the ancillary electronics is on 100a service. Barring a big electric water heater, i fail to see how 100a won't be enough.

If you have gas for heat and hot water, i would do 200a at the house with a 90a sub to the shop

 

[sberry]

You can stop welding or don't start while the comp is running in a 1 or 2 man shop. I have installed a couple dozen garage feeds, we have members here too using 60, a couple with 70A breakers. I use 2 alum wire, could be changed to larger breakers but I have NEVER had a call or trip even from a couple busy garages, one bud running full 5 hp comp and some air cond.
I ran a welding shop a winter from 60, I did have air on another circuit but it all came from 100. Built 200 benches, hoppers, stands for a rebuilding plant. 250 feeder, plasma, 180 for tack up machine. Greedy quarts lights, didn't cut and weld at the same time was all the limitation.

 

[wrenchguy]

imho, its all about the number of spaces for circuits that might be needed. whats the $ difference between the 2 panels? i'd go with the 200, using the theory that nothing stays the same forever. good luck with ur project.

 

[sberry]

I will agree about the spaces. They do make a 24x100 as well as 20. I been using a 12 lately for small subs, the cost isn't much more, lots more room and don't need to be so thrifty with circuits.
I am doing 1 for a guy now,,, doesn't seem to matter about adding a fistful as we go,,, last thing he does is wire. Asks,,, does it make a difference if I want to add an oven,,, if I want to add several circuits for rv.

 

[86turbodsl]

You will never use the full 100 amps out in the shop unless you are running everything all at the same time. Never happen in a one man shop.
I have all of the equipment you mentioned above and then some and have never popped a breaker either in the shop panel our the house panel. That's 35 years of use out of a 200 amp service on the house with 100 pulled to the shop.
200 amp panel in the house will be fine.
Mark

Doesn't that depend on what equipment he's running? My syncrowave 300 pulls 120A at full tilt. That's by itself. Lights, compressor, etc not included.

 

[sberry]

Most people running a 300 synch would have some concept of the power requirements. Most people do not need to prepare for a 100A service machine in a home garage.

 

[wanderer]

My electric meter has three electrical taps on the bottom of it. I only have 200 amp service, but will be putting a 200 amp panel in the garage when is the belt. Can you do this instead of running the garage panel as a sub panel?

 

[u3b3rg33k]

My garage has it's own 200A service drop due to it not making sense to pull a panel off the house (existing 100A service would need upgrading, concrete patio in the way, etc).

if I run the plasma cutter (50A), air compressor (8A), electric heat (30A), and shopvac (12A) all at once that gets to to a theoretical 50% load. I have plans for more big toys, and did consider a theoretical electric car down the road (40A+)

The price difference between 100A service and 200A service was negligible (bigger wire, bigger panel), same monthly service charge. there was basically no reason NOT to go bigger.

without upgrading the house I could only put a 60A sub in the garage.

 

[sberry]

I will agree if you are going to run a service for the building the difference between 100 and 200 is moot. Poco can bring bigger wire in for new 200 too which helps v drop a little under hi load.
There is how ever no more simple way of 100 coming from 200, whole property is under a single main breaker.
There is a big difference between theoretical load and actual. Car chargers are going to offset the calc a bit though. Most (disclaimer there) but most 50A welding and cutting is at about 40 in actual. Its getting less all the time with new machines. Hobarts new Stickmate is now a 200A machine, was a 160 and 230 on AC but new pulls 43 I believe at rated output. 5 less than the old at rated output and most of the worlds work in that class is 1/8 electrode at 120A. I see some of the new inverters way south of 20A on 200A machines.
On the user end this will make the new Stickmate as good as a Dialarc really. Its going to run 1/8 lo hy continuous or as much as a guy can and above duty cycle with 5/32. Whole level better machine from the same circuit.

 

[sberry]

My electric meter has three electrical taps on the bottom of it. I only have 200 amp service, but will be putting a 200 amp panel in the garage when is the belt. Can you do this instead of running the garage panel as a sub panel?

Basically,,,, yes.

 

[wanderer]

Basically,,,, yes.

This is then what I would do. It will save space in your main panel and allow you full amperage in the garage so long as you’re not using it at the house. You may run it by your power company. Mine installs main breakers at the meter, which is mounted on the pole and then run underground into the house.

FYI, I was able to purchase a meter and main breaker for the pole that functions as a transfer switch for a generator. I think it cost me like 75 bucks extra.

 

[alfredeneuman]

My garage has it's own 200A service drop due to it not making sense to pull a panel off the house (existing 100A service would need upgrading, concrete patio in the way, etc).

Many PoCos won't install a 2nd meter to 1 street address. I'd wait to see what the PoCo says.

 

[u3b3rg33k]

Many PoCos won't install a 2nd meter to 1 street address. I'd wait to see what the PoCo says.

To the same physical building I could see that stance, but to outbuildings/barns etc I can't imagine they'd want to give up the additional revenue stream.

 

[alfredeneuman]

Well then, you'd be wrong.

 

[mike93lx]

To the same physical building I could see that stance, but to outbuildings/barns etc I can't imagine they'd want to give up the additional revenue stream.

what additional revenue? the $20 of monthly base rate charges? i can't imagine why they wouldn't do everything possible for that substantial amount

 

[u3b3rg33k]

what additional revenue? the $20 of monthly base rate charges? i can't imagine why they wouldn't do everything possible for that substantial amount

it's free money to them. i had to pay for the drop.

Well then, you'd be wrong.

do they not have duplexes where you live? I've seen separate meters for water heaters.

 

[alfredeneuman]

I should used the term "separate services" instead of "meters".
Sorry
(Duplexes have separate addresses btw)

 

[u3b3rg33k]

They wouldn't give me additional service on the same house, but I'm not sure why I would ask for that.

 

[wyliesdiesels]

To the same physical building I could see that stance, but to outbuildings/barns etc I can't imagine they'd want to give up the additional revenue stream.

Theres been many posts on here where people say that their PoCo will not give a second service to a detached building on the same property.

just because you cant believe it, doesnt mean its not true.

 

[86turbodsl]

Most people running a 300 synch would have some concept of the power requirements. Most people do not need to prepare for a 100A service machine in a home garage.

My point was nobody was asking him what he was going to do out there, which is the determiner of what kind of service he needs, pretty much everybody, you included, said "100A is more than most people need in a home shop"

More investigation is needed.

 

[86turbodsl]

Theres been many posts on here where people say that their PoCo will not give a second service to a detached building on the same property.

just because you cant believe it, doesnt mean its not true.

Depends on the rules of the poco. When i worked for the local one, we would not install a second service on a property without it getting a new address. Dad worked for them for over 40 years, he had a separate service on his pole barn with a house number included.

 

[wyliesdiesels]

My point was nobody was asking him what he was going to do out there, which is the determiner of what kind of service he needs, pretty much everybody, you included, said "100A is more than most people need in a home shop"

More investigation is needed.

Actually i asked him in #4 if he had done load calcs which is the correct way to figure out loads.

 

[u3b3rg33k]

Theres been many posts on here where people say that their PoCo will not give a second service to a detached building on the same property.

just because you cant believe it, doesnt mean its not true.

that's not quite what I facetiously said I can't believe, nor the real point of this thread anyways.

it's easy enough to slap up some stickers with a "B" after it and then take it down when they leave. I'd happily do that to get my service added if I had to, but I don't. my state isn't that level of special.

 

[Diesel Dan]

In Wisconsin we had two separate meters fed off the same transformer, one address. One meter to the house and the other fed the 4 out buildings. If we stayed there longer I was planning on re-wiring and getting rid of that second meter, many months the minimum meter charge exceeded the kW used.

 

[u3b3rg33k]

sounds like my gas meter 6 months of the year.

 

[bugman53]

I upgraded my 200 amp service (160 continuous) to a 400(320 continuous). I have a 200 amp main panel in the house and a 200 main panel in the shop.

The house is 2600 ft2, 4 ton AC with 15kw backup heat, Electric everything, hot tub pulling 60 amps. ect, The shop is planned to have a 2.5 ton AC with 5kw heat strips, Air compressor, a few welders, The amperage was bases on heat running with heat strips while welding and the air compressor kicks on.

There are several advantages to running a 400 amp service and you would be shocked how cheap the difference is when you factor everything in it might even be cheaper than a sub panel if you are following the letter of NEC code.

Most 400 amp meter bases have dual lugs, this is meant to run 2 main panels.
When running wire to a detached building you can run 3 conductor wire with a main panel, if you run a sub panel you are required to run 4 conductor wire.
You can buy 4/0 aluminum underground wire a lot cheaper than even 2 gauge 4 conductor copper wire.
With a sub panel you are limited to 100amps MAX.
200 amp is more common so you panels are cheap.

 

[alfredeneuman]

With a sub panel you are limited to 100amps MAX.

I've worked on quite a few 1600A Subs

 

[wyliesdiesels]

I upgraded my 200 amp service (160 continuous) to a 400(320 continuous). I have a 200 amp main panel in the house and a 200 main panel in the shop.

The house is 2600 ft2, 4 ton AC with 15kw backup heat, Electric everything, hot tub pulling 60 amps. ect, The shop is planned to have a 2.5 ton AC with 5kw heat strips, Air compressor, a few welders, The amperage was bases on heat running with heat strips while welding and the air compressor kicks on.

There are several advantages to running a 400 amp service and you would be shocked how cheap the difference is when you factor everything in it might even be cheaper than a sub panel if you are following the letter of NEC code.

Most 400 amp meter bases have dual lugs, this is meant to run 2 main panels.
When running wire to a detached building you can run 3 conductor wire with a main panel, if you run a sub panel you are required to run 4 conductor wire.
You can buy 4/0 aluminum underground wire a lot cheaper than even 2 gauge 4 conductor copper wire.
With a sub panel you are limited to 100amps MAX.
200 amp is more common so you panels are cheap.

wait WHAT? according to what code?

 

[bugman53]

wait WHAT? according to what code?

No code prevents it the main panel in most homes is your limiting factor. The breaker size and buss bar ampacity limit.

Most of your common home main load centers have a max breaker size of 100 or 125 amps. There are ways to get around this (feed through lugs although some still have an ampacity limint) but you will come out much cheaper to just do a dual lug meter base and install a second main panel on your shop if you need more than 100amps you are probably pushing a 200 amp service anyway.

The cost savings of the wire alone to run 3 v 4 conductor wire is a big advantage to a second main panel.

 

[bugman53]

I've worked on quite a few 1600A Subs

I wish 3 phase was available here! What wire size did you run to those bad boys? Of course commercial equipment is a whole different ball game.

 

[mike93lx]

No code prevents it the main panel in most homes is your limiting factor. The breaker size and buss bar ampacity limit.

Most of your common home main load centers have a max breaker size of 100 or 125 amps. There are ways to get around this (feed through lugs although some still have an ampacity limint) but you will come out much cheaper to just do a dual lug meter base and install a second main panel on your shop if you need more than 100amps you are probably pushing a 200 amp service anyway.

The cost savings of the wire alone to run 3 v 4 conductor wire is a big advantage to a second main panel.

Replacing a meter base is almost guaranteed to be more exoensive than a 4th conductor.