How many amps should my sub panel be? & should I get a gas line for heat?

[Ole Anderson]

A Square D 100 amp Homeline panel with 4 breakers is only $90. Don't think twice on anything smaller, even if you think it is overkill.

[Bob Riefer]

I know the question was around gas line and electric (and answers have covered that already) but I also wanted to mention water/sewer and any data lines. Having just incurred a huge bill to add those items to my barn, I envy those that can accomplish the same things more efficiently during the build process. Probably already on your radar, but just in case.

[Derek Meyer]

I have 400 amp service in my house, and it's exactly as Tom says - the 400A meter feeds a pair of 200 amp electical panels. Mine are side-by-side in my basement. I did it not so much for the 400 amp service as the breaker space - I have lots of dedicated circuits in my house for things like computers, electronics and audio gear. Of course, I over-did the low voltage in my house as well (I have over 10,000 feet of low-voltage cabling throughout my house) with the idea that I wouldn't have to run a bunch of extension cords or network/phone cords across the rooms if I wanted to plug something in. I also hard-wird for intercom, video cameras and home automation. Nearly 20 years later those wires still sit unused. Maybe someday.

I'm looking at doing a sub-panel in my garage, and I'm planning on going with 125 amps. I envision having a minisplit, air compressor and dust collector, along with a single large tool like table saw or planer, running simultaneously. I plan on keeping the main shop lights on the house panel so if the sub's main breaker trips the lights will stay on.

My main issue is that my electrical panels are in an exterior wall in a now finished basement (don't put your panels in a finished room unless you have to - it makes alteration/addtions a real pain) on the other side of the house from my garage. I'm looking at running the sub panel's service cable up the side of the house and into the attic, then dropping down into the garage. For the new garage circuits, conduit on the walls is looking pretty good.

[Ronald Blue]

I have 400 amp service but it's much simpler than your setup Tom. What are the additional boxes? It will depend on your power provider what they require as well. They gave me the meter base specs so I got the one they required. The power company ran my service in. They bored it from the road, set the transformer and ran the power into the meter base. Meter base has two 200 amp disconnects. They feed a 200 amp panel in my shop and a 200 amp panel in the home. The shop is 75 feet from the home. IF the contractor is dragging his feet because of what he's locked in to by the contract offer him an out. Make sure he signs a release if he is agreeable to letting you out. It doesn't sound like you are pleased with him.

I forgot to add to the encouragement to put in floor heat. Mine is operational and it's awesome. It's so consistent and even. Mine will get it's first real test this weekend. Heavy snow and then dropping below zero. I'd put it in the whole garage though. Just my .02.

[Rich Engelhardt]

IF the contractor is dragging his feet because of what he's locked in to by the contract offer him an out. Make sure he signs a release if he is agreeable to letting you out. It doesn't sound like you are pleased with him.

I was fed up with that buch of clowns months ago.
Our contact person that was handling our build went on maternity leave in January 2020. In March the virus hit - but - that didn't really have any effect on our build - at least not right away.
What screwed up our build was that the people that were filling in for our rep, didn't give a squat and never followed through on anything.

They told us our foundation was going to be dug in April 2020. In May of 2020, when someone finally got around to answering our twice a week calls and emails, they started asking us if we had done this or done that and why weren't we doing the stuff they told us to do to get the ball rolling.
The answer was simple - - they had never told us anything about what they wanted us to do.

Then, at the end of June 2020, when still nothing had been answered, we got them on the phone to see what the problem was and they were astounded that we were calling since after alll "we had never contacted the bank to arrange a construction loan".
Which was 100% untrue.
I hit the roof.
We went down and straightened that out. I let my wife do all the talking. When they asked me about it, I told them I hated the house & I was sick of them and they were nothing but a fly-by-night outfit that had a lot of (*&lls) calling themselves builders & as far as I was concerned, I wanted out. They should talk to my wife and leave me out of it.

The biggest problem at this point is - we have the foundation in. Up until this point we could have sucked it up and sold the lot and actually turned a profit. Not anymore. If we pull out now, we'll lose about $30k.
If we try to start over with someone else at this point & with pricing like it is - will be looking an additional $50k in extra cost right in the face.

I hate building......I swore I'd never do it again after we had the place we're in now built back in 1986.

[Tom M King]

I have 400 amp service but it's much simpler than your setup Tom. What are the additional boxes? It will depend on your power provider what they require as well. They gave me the meter base specs so I got the one they required. The power company ran my service in. They bored it from the road, set the transformer and ran the power into the meter base. Meter base has two 200 amp disconnects. They feed a 200 amp panel in my shop and a 200 amp panel in the home. The shop is 75 feet from the home. IF the contractor is dragging his feet because of what he's locked in to by the contract offer him an out. Make sure he signs a release if he is agreeable to letting you out. It doesn't sound like you are pleased with him.

I forgot to add to the encouragement to put in floor heat. Mine is operational and it's awesome. It's so consistent and even. Mine will get it's first real test this weekend. Heavy snow and then dropping below zero. I'd put it in the whole garage though. Just my .02.

The boxes on either side of the meter base are 200 amp disconnects. The old 200 amp panel is directly inside the wall behind the left disconnect box. That disconnect box is setting where the old meter base was. I was able to use the old service entrance wire by doing it like that, without having to do anything to the brick wall, or even having to open that old panel.

The box on the right is also a 200 amp disconnect, but has spaces for a number of breakers in it too. I plan to feed two subpanels, an outside car charger receptacle, and one inside the garage that's inside that wall from that right box. It will still leave a few breaker slots for future additions.

It's a lake rental house, rented mostly for weekly vacations, and there are a lot of electric cars on the road here. During the offseason, they are mostly rented by people who can work from wherever they want, and the number of Tesla's on the road is substantial during the Winter here, driven by that class of renters.

edited to add: The power company provides that meter base. You can buy something different if you want, but it has to be approved, and that takes a while. I already had most of that stuff, leftovers from other changed jobs at old houses. I only had to buy the right box, and a couple of ground rod clamps.

[Ronald Blue]

edited to add: The power company provides that meter base. You can buy something different if you want, but it has to be approved, and that takes a while. I already had most of that stuff, leftovers from other changed jobs at old houses. I only had to buy the right box, and a couple of ground rod clamps.

My power company told me what to get. The disconnects are in it. The transformer is 3 feet away. It's also a lever bypass which my understanding of that is the meter can be changed without killing the power. My 200 amp panels are still protected by a main breaker in them as well. Nothing was provided by the power company. Well I guess it was but the 5K I paid to have power brought in covered it so I paid for it anyway. I guess in the end you have to satisfy the power company and maybe the electrical inspector if you have one. There is none here.

[Tom M King]

Yes, a lot of local preferences turn into requirements. It used to be that if the main panel was right inside the wall behind the meter, no disconnect was required outside. Now, all the fire departments around here want a cutoff outside, so the Inspector requires an outside disconnect. All main panels still have a Main breaker.

[Randall J Cox]

I just added a 125 amp subpanel and filled it with five 20 amp 240v circuits and two 120v 20amp circuits. This was added into a 3-car garage that already had 120v outlets but no 240v outlets. Now a happy camper. Randy

[Andrew Hughes]

Isn’t a 200 amp panel just a box with more breakers then a 100 amp panel? It doesn’t necessarily mean your going to have more amps in your service from your utility.
Nothing wrong with adding more more breakers I think it’s great to have each machine on its own circuit. But it doesn’t necessarily mean one can start buying machines with 10hp 3 ph machines. Or 20 hp Rotary phase converters.
In my area our utility is sce. When I moved into my house the line drop from the power company was 6 gauge aluminum wire.
Ive been upgraded from sce twice first a transformer to service the end on our street. Then a new line drop that went mid span between poles to keep my wire out of my oak tree to keep squirrels away from chewing on the neutral.
I was able to talk the guy into giving me a 2/0 wire line drop. I asked for copper but he said it’s too heavy and would pull the leader head pole from my house. So I got aluminum.
I just wanted to share what I’ve had to learn so that others can consider what it means to add a panel.

[John K Jordan]

...
I was able to talk the guy into giving me a 2/0 wire line drop. I asked for copper but he said it’s too heavy and would pull the leader head pole from my house. So I got aluminum.
I just wanted to share what I’ve had to learn so that others can consider what it means to add a panel.

Back in the '70s I was working as a steel inspector on a hospital construction site. The electrical contractor gave me a the "short" end of a spool of 4/0 copper wire. I was rewiring my small house and replacing the old fuse box with a 200 amp breaker box. I installed the box and a new steel conduit/pole with three lengths of the 4/0. The utility guys making the connection from the street couldn't believe I used that wire until I told them the story! (BTW, they also used aluminum wire from the street, bundled with a steel cable for strength.

The panel had connectors large enough to accept the 1/2" conductors. The only problem I had was making the bends on the wire as it entered the box so I could make the connections! I ended up using a 4' length of pipe as a cheater bar.

About squirrels: the house here on the farm has a 450' underground conductor from the pole on the street to a transformer that feeds the house and shop. The connection at the pole is through a fuse. In the 18 years we've been here five times the fuse blew accompanied by an explosion that sounded like a dynamite blast. Three times it was caused by an unlucky squirrel who shorted the line at the top of the pole with its body. Each time we found the fried squirrel on the ground. Fortunately, the neighbor works for the utility company and could replace the fuse using a hand-held pole.

Another time the utility crew said it was from termites attracted to the heat from the transformer on a concrete foundation in the woods near the house. The termites apparently made a connection shorting out and melting the end of the 7200v line, fixed by sliding the transformer over a couple of inches to reconnect. And the last time we heard the fuse explode turned out to be a tiny pinhole in the insulation on the underground conductor - this required about 6 hours, a backhoe, and three guys to cut out the spot and make a splice.

underground_elect_repair.jpg

The guy who built the house in the '80s paid a small fortune to put the power underground. His wife didn't want the power company cutting a 20' wide swath through the woods for power poles!

JKJ

[Tom M King]

A squirrel shorted out the transformer that feeds our house, a couple of years ago. It made an arc like a HUGE welding arc, burned the transformer, which caught the pole on fire, and it burned all the way to the ground by the time (which was probably ten minutes) the fire department got here.

[Jim Becker]

Isn’t a 200 amp panel just a box with more breakers then a 100 amp panel?

It distils down to that with the addition of the buss inside of the panel is designed to handle up to 200 amps beyond additional space if it's a larger panel. Amperage and panel physical size isn't directly tied in some cases...you can have a smaller panel physically that is rated for higher amperage amounts. Example, when I was choosing a 100 amp panel for my temporary shop, I opted for one with more physical space, given multiple breakers would be double pole for 240v.

[Andrew Hughes]

Yes that’s how understand it Jim. The neighborhood i live in has all the wires on poles the last line man I spoke says it’s actually better to have the line in free air space. I wonder if it’s a heat thing or the electrons are more happy.
Tom and John shared some experience with squirrels something we have plenty of the chew everything. In summer they look to expand their burrows so it’s a consistent fight. I’ve been winning every since I got friend Sheridan
Good Luck and happy new year

[Rollie Meyers]

All this talk about the 2020 NEC you only have to comply with it if your state has adopted it here is a link of States that have. https://www.mikeholt.com/technical-nec-menu.php There a number of requirements also that some have not gone over well, GFCI's are now required for 240V equipment, including ranges, clothes dryers, A/C condensing units which has caused major issues because some newer HVAC will not run with GFCI's because of normal leakage that is read as a fault causing it to trip, because whoever proposed the change and the code committees never consulted UL, or the manufacturers if it, it has led to States who adopted the 2020 to suspend the requirement for now, the only way otherwise is to install the GFCI, and not have A/C, the GFCI requirements also applies to 240V receptacles in shops & garages, VFD's do not work on GFCI's, either. BTW, the reason that the GFCI was required is someone improperly installed a condensing unit that was not grounded, and later somebody touched the unit and a metal fence after the unit had a fault, & was electrocuted, sad story but if the hack had installed it correctly the fault would have cleared, and would have been a simple trouble call, there was no need to add that code requirement. Here in CA the outside disconnect is a non issue most homes use a meter main panel outdoors so the main is already outside. Another requirement is that surge protectors are required for services under the 2020.