Electrical Question - House Addition - Power from garage?

[logan1211]

Hey all!

Will try and summarize as best as possible. Slightly backwards from most posts running power TO their garage from the house

Ultimately we've done a very large house addition due to some kids we're adopting.

- Our "existing" house has 200 amp service, single panel, easy.
- I've got 200 amp separate service ran to my shop. This run comes from a meterbase installed on utility pole and I've got URD in conduit to my shop main panel
- I've got a stupid quote to upgrade to 400 amp service on the house (we're adding like 9 tons of HVAC and quite a few additional loads)
- We live rural with no building codes or anything except for septic/well

Is there anything crazy, inherently bad/wrong/significant code violation about running 200 amp service from my "shop" meter on the pole to my new 200 amp panel in the addition section?

Assuming it's probably bad due to single family home, 2 meters, multiple disconnects, etc. But just wanted to get a hivemind thought. It certainly would be much easier to accomplish than the upgrade, running new service entrance cables to addition panel, etc.

Appreciate any feedback.

 

[sberry]

Only 1 service to a structure. I don't recall what 9T of air calls for???? There is times it can pay to change a few major appliances to gas, cheaper. What are the other major loads on the house?

 

[logan1211]

Large items:

- 3x 4.5 Ton AC/Heat Pumps
- 3x Air Handlers/fans
- 2x 4500 watt Water Heaters
- 2x Washers
- 2x Dryer
- Stove

House is 7 BR / 5 Bath

 

[Norcal]

As was said in post #2, only one feeder to a structure.

 

[Bert_]

Large items:

- 3x 4.5 Ton AC/Heat Pumps20A each
- 3x Air Handlers/fans ~5A each
- 2x 4500 watt Water Heaters 19A each
- 2x Washers 10A each on 120v
- 2x Dryer20A each
- Stove 35A running full blast, whivh it never will.

House is 7 BR / 5 Bath

Those are going to be pretty close numbers for your appliances.

Doing a full load calc would be on your best interest.

That is a LOT of air conditioning.

 

[logan1211]

Good stuff. Thanks all. Appreciate the replies.

 

[jeepxj]

do you live on the sun?

 

[brewchief]

I've never seen a 4.5 ton AC, something in the 4 or 5 ton range is going to draw 20-25 running, possibly close to 30 on a hot day if it's a bit dirty. If they are heat pumps do the air handlers have heat strips? That could add 20-40 amps per air handler and those can run at the same time as the heat pump.

Is Natural gas or propane an option for heating, water heating, dryer and cooking?

Sent from my SM-G965U using Tapatalk

 

[wyliesdiesels]

Your plan wont work as is.

Cant have more than one feed to a structure.

If you want to feed it all from the shop service, you will need to abandoned the service on the house, convert the main service panel to a subpanel, unbond the neutral bar, and run 4-wires to it.

I assume you want to run from the shop because its closer to the addition. This wont work. You need to feed off of the panels at the house.

 

[sberry]

The only 200 I saw overloaded was a tavern, had way more than this on it, whole bunch of fryers, air con, microwaves, lights, coolers, coffee pots.

 

[strutaeng]

Wow, that's a lot of current! Yes, they don't make conventional DX split systems that are 4.5 tons, after 3.5 tons, it goes to 4 tons then 5 tons.

How many square feet are you adding? (3) 4 or 5 tons is a lot!

I'm wrapping up a 2,000 sq ft. 2-story addition to my house. I had the little 60A upgraded to 200A main panel years ago. The overhead line was in the way and I talked to a guy and the plan was to install temporary pole and feed the main panel temporarily while framers did their work. He was going to install a new main panel on the new construction wall and transfer existing 240V to new main, then make the old main as a subpanel. Kinda of a mess.

At the end, I converted to underground service and went around the house and left the main intact, and installed a 125A subpanel for the new addition. All I'm saying is there might be another way to make it work.

I have natural gas, so I didn't need a huge electric service.

BTW, congratulations on your decision to adopt!