wiring a detached Garage from house

[BigDawg99]

i am planning on wiring a detached Garage from my house panel..my house panel is a 200amp and so is my garage..I plan on running a Fridge,Stove,deep Freezer and some lights and plugs..they are Both Single Phase Panels..

If someone can tell me what wire i need to run and what size of Breaker i would need to install in my house Panel..i would greatly appreciate it..

 

[Aceman]

#2 al mhf, 90 amp breaker.

 

[wyliesdiesels]

#2 al mhf, 90 amp breaker.

I was gonna suggest the same thing, but the problem is he didn't tell us what the distance is...

 

[pattenp]

Aceman gave you the down and dirty answer. That cable is for a direct bury or can be put in conduit underground to the garage. The 90 amps is the max load for #2 aluminum. It would be helpful to know the distance of the run and where you live, US or Canada or the Land of Oz.

Edit: MHF = Mobile Home Feeder.

 

[RetiredCPO]

I was about to the same thing when my electrician came up with a better idea. I fortunately have an over head power line entering my property and passes about 50-feet from the garage. Rather then extend electricity from the house, (about 50-feet) he had the power company put in "new service" to my garage. The cost wasn't that much more than extending from the house and eliminated trenching, drilling holes in house walls, etc. Cost, I think I came out ahead a little. The power company sends one bill with both readings so that eliminates a small hassle. But the big advantage I see is that there is no power drops in the house (lights dimming, electric motors slowing, etc.) when I am running multiple tools in the garage. In a previous attached garage I would be running my table-saw, dust collector, heater, and the air compressor would kick in and the whole house and my tools would slow or lights would dim. I have none of that now. In my attached garage I rarely, if ever, blew a breaker, but I was always aware of what I was running. Now I don't worry about it at all. Last but not least, I had to have some electrical work done in the house that required a total power disconnect for the better part of the day. (ancient house what can I say) Using some pretty heavy duty extension cords we were able to keep the furnace running and have some light to work with.
Although I don't know what your situation is, if the separate service option is available to you without breaking the bank, I would really think about it.

 

[ixlr8]

Although I don't know what your situation is, if the separate service option is available to you without breaking the bank, I would really think about it.

Definitely something to look into. My neighbor was about to have power taken from her house to her new garage. She asked me about getting out my backhoe and digging the trench, was not going to be fun as there were several old tree stumps in the way. So it was going to cost her a bunch for the trench and the electrician to wire the power from the house to the garage... of course an updated panel in the house as the original one from the mid-50's didn't have any room left in it. She called the power company and they said don't bother with all that, they just dropped a new service feed straight to the garage with a new meter and didn't charge a thing for it, saved her a few grand.

 

[Falcon67]

If the OP is in Texas, the second meter drop would be billed at commercial rates. It's allowed by the tarriff. Could also be minimum billings too. Our co-op has a minimum $35 billing for a meter. Not paying $35/mth paid for the wire, etc real quick. Same at the old shop - had a nice short drop from the pole right behind the building to it's own meter. Nice. Started adding up the bills - ran a 60A service to the shop and moved the service entrance, saved big $$$ real quick.

 

[Charles (in GA)]

I built a detached building 80 ft behind my house. I wanted a full 200 amp service available to it, and the cost of replacing my house's 200 amp service with 400 amp and installing dual disconnects was going to be expensive. I was also looking at having to replace the house's three wire service (no exterior disconnect) with four wire and separating all my grounds and neutrals in the panel in order to comply with code during the 400 amp upgrade. House has an underground servic and it was looking very costly.

Instead I had a 200 amp service dropped down a pole that is located across the driveway from the house (main feed for the subdivision runs the length of the yard, but the house is fed from an underground service and transformer off the street, no idea why, it cost the POCO several hundred feet more cable). Anyhow, I pay a second base meter fee, but its only about $14 or so (not sure, the bill does not break it out nowdays, it did several years ago however and it was then $14). The second meter is billed at Residential rate. Engineer told me it would be commercial rate but the lady in the POCO office that set up the workorder for the new service said it would be residential rate as it was not commercial and said the engineer was an idiot (quoting her). I had other issues with this engineer also, as he insisted on a 30 inch deep trench (I had to hand dig across the septic field before the POCO showed up with the trencher) and the crew who trenched and installed ALSO said the engineer was an idiot and that I only needed a 24" trench. Apparently he was rather famous in that particular district office of the POCO.

I too like having two separate sources of power. I once had a failure of the underground feed to the house on a Friday evening, lost one hot leg. POCO was not going to locate and repair the problem till Monday, so I just ran extension cords from the shop to the house for the fridge and a couple of lights and I was fine till Monday. Made showers kinda cold on Sat evening and Sun however.

Charles

 

[BigDawg99]

Thanks for the replies..Much Appreciated..My building is about 25 feet from house..almost attached to the house..i live in NB Canada..25 feet is Basically from Inside my House panel to the Garage Panel...i have looked at the breakers in the Garage panel and a total of 90amps is on there..( not sure if that is any importance )..thanks once again for all the replies..Great Site you have here and very helpful..glad i stumbled across this site..great Knowledge and Help...

 

[Norcal]

Here in CA , a 2nd meter on residential property is almost out of the question, but know of one instance where a 2nd 100A service was installed to power a electric ceramic kiln for "hobbyist" uses.

 

[wyliesdiesels]

O yeah, I forgot about that. That's a CPUC mandate right Norcal?

 

[Higgins]

Here in IL I added a 125A panel to the lower garage, told ComEd it was for business and they said no problem!

 

[Falcon67]

O yeah, I forgot about that. That's a CPUC mandate right Norcal?

Called the PUC in Texas. When I complained to the PUC that AEP was charging me commercial rates on a residential meter, they sent a nice letter that basically said "If you'd read the tarriff first, you'd know that..." etc. Live and learn. Besides, of the $35 I'm saving on the co-op, I spent $7 of that on a Dish Network feed.

 

[matt151617]

i am planning on wiring a detached Garage from my house panel..my house panel is a 200amp and so is my garage..I plan on running a Fridge,Stove,deep Freezer and some lights and plugs..they are Both Single Phase Panels..

If someone can tell me what wire i need to run and what size of Breaker i would need to install in my house Panel..i would greatly appreciate it..

Remember you need 4 wires... 2 hot, 1 neutral, 1 ground. The neutral needs to be isolated from the ground in the garage subpanel. Also you need to have 2 ground rods coming off the garage.

 

[Charles (in GA)]

Called the PUC in Texas. When I complained to the PUC that AEP was charging me commercial rates on a residential meter, they sent a nice letter that basically said "If you'd read the tarriff first, you'd know that..." etc. Live and learn.

As if they really expect you to read hundreds of pages of gibberish and tables of numbers to determine that. Just a their polite way of showing you the middle finger and saying the utilities bought them off.

If my POCO ever comes along and changes the rules, they are going to find themselves installing a new residential 400 amp service. As it is now, my shop's total bill is about $20 to $30 a month and I'm happy with that.

Charles

 

[wyliesdiesels]

Speaking of utility scams, our local newspaper just did an investigation into MID's(public electric co) rate hikes over the years and discovered that they're keeping water rates artificially low for farmers by over charging all their electric customers. It use to be cheaper to get electricity from a public owned electric co. but since many of the board members are farmers, that has all changed! The neighboring TID public electric co.(gets its electricity and water from the same damn) has not raised its rates like MID has! Even PGE in neighboring towns doesn't charge as much as MID does!

There have been people protesting outside MID's offices for weeks! Maybe something will come of it just like the board canceled the sale of water to SF!

 

[tfi racing]

Remember you need 4 wires... 2 hot, 1 neutral, 1 ground. The neutral needs to be isolated from the ground in the garage subpanel. Also you need to have 2 ground rods coming off the garage.

Not in Canada,no ground rods or plates allowed past the main service,but the 4 wires are required...

 

[wyliesdiesels]

That's odd cause the detached building could get hit with lightning and then the surge has to travel all the way down the EGC between the buildings, through the neutral bus, and then through the GEC to get to the rod or plate! That's not very efficient for discharging lightning!

 

[Aceman]

Not in Canada,no ground rods or plates allowed past the main service

Not allowed or not required?

 

[james_98188]

I've installed a storage shed/workshop about five feet behind my garage, and am installing a 5hp upright compressor in it with the intention of piping shop air into the garage to save on space and cut down the noise.

As for bringing power to the shed (I'm in Washington State), they don't allow more than two additional circuits coming from the house panel (already done for garage equipment), and they also require a subpanel on the outbuilding. I'm assuming this means they'll run power from my existing meter to the shed's subpanel? Or is a second meter required?

 

[pattenp]

I've installed a storage shed/workshop about five feet behind my garage, and am installing a 5hp upright compressor in it with the intention of piping shop air into the garage to save on space and cut down the noise.

As for bringing power to the shed (I'm in Washington State), they don't allow more than two additional circuits coming from the house panel (already done for garage equipment), and they also require a subpanel on the outbuilding. I'm assuming this means they'll run power from my existing meter to the shed's subpanel? Or is a second meter required?

Why can't you take power from the garage sub-panel to the shed sub-panel?

 

[Dick in Wisconsin]

Although I don't know what your situation is, if the separate service option is available to you without breaking the bank, I would really think about it.

Am I glad I looked at this link and MANY thanks to Mr. RetiredCPO. My new garage will be BETWEEN the house and the pedistal! I "was" planning on putting a 90amp breaker in the house panel and then digging a trench and burying a cable/conduit to the garage. I'm going to check with the power compnay (WE Energies) and see if they will put a 200amp service to the new garage and put both metets on ONE bill!

Thanks Garage Journal Forum!