Planning stage questions

[Jetsurgeon]

Hello, I am planning my garage/shop build, I am in Central Florida, it is 24' x 48' x 12, walls (15' overall height). It will be a 150 MPH rated steel building that I will have close cell spray foam insulated and will wall it off to two, 24' square rooms. The rear room will have a mini split installed, the front a 4 post lift. I am planning a 200 Amp service for the garage, and looking for advice. The building/slab will be the dark blue area, 5' from the side of the house, with the driveway extended as shown. Where the Red circle is resides the electrical panel for the house. In the side yard by the Yellow rectangle is an "Electrical Pull Box". Do I need to pre plan (before the concrete work) the electrical run for the Garage (split from the house), or will they run it from the "Pull Box"? Thanks!

 

[racecougar]

Is there an extra 200A service already available at the house? Likely not.

Who is they? Why not ask them directly?

 

[Jetsurgeon]

Is there an extra 200A service already available at the house? Likely not.

Who is they? Why not ask them directly?

They in general as what do electrical contractors usually do? It is a 200A panel in the main house, as it is a 5 year old house in FL and everything in the house is Electric

 

[racecougar]

You intend to retain the current service in the house though, correct?

 

[cvairwerks]

A 24' long room with a lift is going to give you barely any room to get around the vehicle, unless you have small ones, and nothing on the wall opposite of the access door. Depending on construction, you are going to loose at least a foot of that to the internal wall and the access door.

I'd take a little bit of time and stake out a 24' long room and put the biggest vehicle you have in it and get a true feel for the space.

 

[ericm]

Where's the meter for the house? Normally the meter would be on the house. Then what you'd do if you have the capacity is put a big breaker in the house panel and run wire from there to the new garage. Unless you're going to be growing marijuana or running an aluminum smelter you probably do not need 200a to the garage.

You should make a spread sheet of the things you want to run in the garage, and what's in the house, and have an electrician do a load calc. You'll probably need that anyhow. The power company often requires it if you're changing the service (like adding a service for the garage). If you do a sub panel off the house panel you'll want the load calc to know if it'll all work under a single 200a service.

You need the load calc. Adding up all the breakers is not the right way to do the load calc. It will result in a number that's way too high.

If you really want 200a to the garage that is probably an additional service and its own meter. Sometimes the PoCo does some of the work to get the new meter installed, sometimes they don't, or they do it and charge you. There is usually an additional charge for having an additional service.

 

[dcg9381]

Where's the meter for the house? Normally the meter would be on the house. Then what you'd do if you have the capacity is put a big breaker in the house panel and run wire from there to the new garage. Unless you're going to be growing marijuana or running an aluminum smelter you probably do not need 200a to the garage.

This. The easiest, cheapest, and perhaps best way to do this is to throw a breaker on your current electrical panel. If you have questions about that post up a photo of the panel.

A separate service beyond 200A is probably unnecessary, even with a mini-split, lift, welder, whatever. Guys are telling you "load calc" are correct. Or put a monitor on your main to see how much power your existing house is pulling from your main currently. Most of us have more than enough power to spare from a 200A main.

On concrete work, you can always add electrical conduit under it. Personally, I'd definitely drop in some 2" conduit in stategic places across that drive, maybe some 3/4" also... Just "future use" - beats burrowing under the concrete in the future. I also like to put 1" conduit "spanning" the building foundation, again "just in case". It's easier to run electrical under than it is over or around.

If you are "for whatever reason" going to split fed electrical meter, yes, you'll want to plan conduit from the yard (likely that "pull box") to where it comes up into the shop (interior or exterior).

 

[ericm]

Here's a load calc tool that you can use to estimate what yours would be: https://ask-the-electrician.com/residential-electrical-load-calculation.html

I'd still get an electrician to do one. When I did one ~4 years ago it was $300. If I'd built that shop I'd have needed to give a copy to the PoCo along with my permit and plans, and then wait for them to tell me how much it cost. (Lots- it's PG&E, the worst utility in the country). That was with a sub panel for the shop, not a new service.

For the new place in Oregon I also needed a load calc from a licensed electrician but it was for the PoCo to decide how we were going to put in a new service. They decided we need a transformer to run the service.

 

[CraigStu]

I'd find out who to talk to at the electric company. Maybe someone will come out to look and see what you are planning to do. Put a few stakes in the ground to mark your expected build location. It's fine to get thoughts from the web but, none of it matters. The electric company will tell you what they will do to accomplish what you want.

 

[Jetsurgeon]

Thanks all, the current meter is where the red dot is on the original post, I did just use an online load calculator and for what I am planning it calculated a 70 Amp load (240V air compressor, garage door opener, 4 "small appliance circuits", a 240V 18000 BTU mini split, and the heating elements for my electric brewing system (also 240V and about 25A when running). I like the idea of running some conduit under the slab, will definitely consider that, much cleaner looking. So I guess a 100A panel will probably work.

I don't think there is any space left on the main panel as we just had an electrically heated, in ground pool with a swim in place system (that has a 10HP motor driving a 0- 2500 GPM variable speed pump) installed. I believe all the breaker spots on the main panel are taken now.

I guess I was really wondering if they would pull it from the existing panel on the side of the house opposite where the new garage is going, or pull it from that pull box in the yard to the other side of the garage. To ERLCM's point, maybe I just need to get an electrician out there to take a look. I am a certified Aircraft Electrician, so will do most of the interior work myself once the panel is installed, but never installed a service or sub panel, so I'll leave that to someone who does that all the time!

 

[Jetsurgeon]

A 24' long room with a lift is going to give you barely any room to get around the vehicle, unless you have small ones, and nothing on the wall opposite of the access door. Depending on construction, you are going to loose at least a foot of that to the internal wall and the access door.

I'd take a little bit of time and stake out a 24' long room and put the biggest vehicle you have in it and get a true feel for the space.

My longest vehicle is a 1972 Dodge Challenger, which is 16' (110" wheelbase) and the Bend Pak lift I am looking at is 16 1/2' long including the ramps, so should have plenty of room I think

 

[cvairwerks]

My longest vehicle is a 1972 Dodge Challenger, which is 16' (110" wheelbase) and the Bend Pak lift I am looking at is 16 1/2' long including the ramps, so should have plenty of room I think

Remember that will work unless you need to make the front wheels hit the forward stops....you'll have a couple of feet of the nose overhanging the front of the lift. Also, unless you are installing high lift tracks for a conventional type garage door, you will need to push the lift a bit further away from the door, for clearance when something is on the lift and the door needs to be opened or closed.

 

[racecougar]

I guess I was really wondering if they would pull it from the existing panel on the side of the house opposite where the new garage is going, or pull it from that pull box in the yard to the other side of the garage.

You'll almost certainly not have a feeder rated for 400A going to your current 200A box.

 

[manwithtools]

You'll almost certainly not have a feeder rated for 400A going to your current 200A box.

I'd tend to agree, but interestingly my house did have exactly that (actually 320 amps, but they call it a 400 amp feed). I was able to add a second 200 amp service panel without changing the feeder wires from the PoCo. Mine is a 2-1/2 year old home on 5+ acres, I assume the PoCo saw the need to add a second service panel when some one built a future shop, which is exactly what has happed.

I suggest the OP contact his PoCo, as they will have a preference on where to get the power from.

 

[racecougar]

Exceptions certainly exist.

Yes, the OP should absolutely talk to the power company, as that entity will have the answer here.

 

[CraigStu]

I would look at actual 100 and 200 amp panels. I don't know if there is a standard of rated amps vs # of breaker positions but you don't want to run out of room to add a circuit or 2. As a point of reference our house has two 200amp panels where the power comes into the garage. Each panel has a 100 amp breaker that feeds a sub panel in the house. One 100amp panel in the basement and one 100 amp panel in the second floor.

 

[My Old Tools]

My last two shops I did almost the same thing. Previous one I ran mobile home feeder on a 90 amp breaker to a 100 amp sub panel in the shop. Current shop was a bit more run so we ran copper on a 100 amp breaker to a 100 amp sub panel in the shop.

 

[Jetsurgeon]

Thanks all, I will contact the PoCo, but thinking now 100A will probably be fine for what I will be running