Approach to power detached garage?

[KML]

I would appreciate some feedback from experienced members on the approach I intend to use to connect power to my detached garage in central Florida. My house has a 200 A panel and separate meter can outside. Of course, the detached garage is on the opposite side of the house. I was thinking of going with a 2x200A meter main combo (poco approved) - the wires from the old meter base and the wires going into the house look like they will just barely reach. Maybe that is reason enough for a separate meter base?

One day down the road, there is a decent possibility I would add solar PV on the garage roof, or a whole house (and detached garage) natural gas backup generator behind the garage (both at once might be tricky). I would like to backfeed the garage panel with this power - I'm aware code would require a big panel, to keep from overloading the bussbars.

Meter main combos do not lend themselves to whole house transfer switches correct? Is that another reason not to go with a meter main combo? What is the best approach to accomplish something like this?

Has someone here successfully done something like this before?

Thanks

 

[wyliesdiesels]

First off, since u have a divorced meter, the only way to power your garage is by running a feeder into the panel in your house. Sounds like this may be a challenge.

If u do switch to a meter main combo, the house panel will need to be reconfigured into a subpanel which means isolating the neutral bar, adding a ground bar or bars and moving EGCs/grounds over to the new bar(s).

This also means u need a 4-wire feed, which depending on how the panel is fed, may mean running a new feeder. If its individual conductors in conduit, u could just add the EGC. Or if metal conduit, u can use the conduit as the EGC. If its a 3-wire bundled cable such as SEU, then U have to pull a new cable as u cant add separate wires to bundled cables.

Do u really need 200a in the garage? Is it a one man shop? What tools will u be running?

The generator is a whole nother can of worms!

 

[theoldwizard1]

• 2 meters means 2 bills. There are minimum charges for each meter. $$$
• A meter main combo with 2 disconnects/breakers is a good idea. Be careful that the POCO isn't going to charge you for upgrading the drop from the pole.
• Wire can get expensive quick !
  • How much power do you REALLY need in the garage ? 60A is usually enough for a "one man" hobby shop even with A/C
  • Can you tap off of the load center (breaker panel) in the house ? Shorter distance to the garage

 

[theoldwizard1]

The generator is a whole nother can of worms!

ABSOLUTELY ! There is no APPROVED way of using that same wire to send power from a generator/solar from the garage to the house.

 

[wyliesdiesels]

• 
  [*]2 meters means 2 bills. There are minimum charges for each meter. $$$
• A meter main combo with 2 disconnects/breakers is a good idea. Be careful that the POCO isn't going to charge you for upgrading the drop from the pole.
• Wire can get expensive quick !
  • How much power do you REALLY need in the garage ? 60A is usually enough for a "one man" hobby shop even with A/C
  • Can you tap off of the load center (breaker panel) in the house ? Shorter distance to the garage

Where did he say anything about dual meters?

ABSOLUTELY ! There is no APPROVED way of using that same wire to send power from a generator/solar from the garage to the house.

Not true!

I did a solar system back in 2007 where the detached garage had a solar system. We put in a fused disconnect on the house that fed into the meter main. This was required so that the garage solar system could be disconnected from the service.

The reason i said it was another can of worms is because of the different options(manual transfer switch, auto TS, interlock, etc.) and the OP wants it to feed both house and garage. But there is no feed to the garage yet so he should take care of that first.

Also, if he is gonna have a backup generator as well as solar panels, the solar system IIRCC would need to be disconnected during generator use.

 

[KML]

The panel to inside my house is on the opposite side of the house from the outside panel, and it is completely full, with most of the bottom half being mini breakers. The outside panel has 6 of the 8 breaker positions taken for the bedrooms, bathroom, etc on that side of the house. I did not want dual meters. As far as loads in the garage go, there could be two electric cars (years from now). I suspect the labor of getting power to the garage will be high enough that bigger wire (4-0 or 250) will only be a little more money. I don't want to ever redo it or add to it. Does that shed some light on why I do t want to power the garage from the panel in the house? Is there another approach I should consider?
Thanks in advance

 

[wyliesdiesels]

The panel to inside my house is on the opposite side of the house from the outside panel, and it is completely full, with most of the bottom half being mini breakers. The outside panel has 6 of the 8 breaker positions taken for the bedrooms, bathroom, etc on that side of the house. I did not want dual meters. As far as loads in the garage go, there could be two electric cars (years from now). I suspect the labor of getting power to the garage will be high enough that bigger wire (4-0 or 250) will only be a little more money. I don't want to ever redo it or add to it. Does that shed some light on why I do t want to power the garage from the panel in the house? Is there another approach I should consider?
Thanks in advance

Ok well that changes things. Would have been good to know that u have a meter main service panel on the outside. In your OP u said meter can which is different than a main service panel.

U should feed the garage from the main service panel and NOT the house subpanel. It WILL make a difference when it comes to voltage drop and lights dimming in the house when large loads are started or operated in the garage.

We cant give u a wire size when we dont know the wire length....

 

[KML]

To be clear, my outside panel, near but seperate from the meter ,has one big 200a breaker and 6 small breakers for rooms on that side of the house. I have another panel, completely full, inside the house attached garage. While I would appreciate a wire size rec, I would actually be more curious as to the best wire type to run thru the attic (around 80 feet) and then run another 20 feet underground to the garage. Trenching around the house means going around the pool/large patio out back, or going around a couple very big trees and septic out front. The attic run would be a LOT shorter if possible. I'm happy to use conduit for the short run underground from the house to detached garage with the attic approach...

Thanks again for your time

 

[wyliesdiesels]

Does the outisde panel feed the panel in your attached garage?

What big loads do u have on the house subpanel?

U said that panel is full and depending on a load calc may be maxed out forcing u to connect the garage at the main service panel on the outside.

 

[ChevyJr]

I currently am going through this scenario and wanted to run through it to receive feedback before I complete it this Memorial Day weekend.

The main power will now be at the garage and the house will become the sub-panel. I understand that I have to remove the bonding screw in the house to isolate the neutrals from the grounds and then add a ground bar. The grounds will move to the ground bar and the neutrals can stay where they are.

I have the Square D Homeline 100 amp Load Center

http://www.homedepot.com/p/Square-D...ERCH=RV-_-rv_homepage_rr-_-NA-_-204836397-_-N

It has a main breaker on top, which I assume I need to remove and replace with two lugs, both being the hots from the 100amp fuse in the garage (the garage will be 200 amp service). As far as the feeder wire from the garage to the house, I was thinking 3 wire SEU (#2 aluminum or #4 copper by code, think aluminum since its easier to bend) would be best. I do not believe I need 4 wire as the current main power, at the house, is grounded to two ground rods so I would only need the two hots and neutral wire.

As I am sure someone may wonder why I am going this route, the energy company is requiring me to set it up this way because pulling a power sources from either pole (2 poles in the back yard) in my back yard cross over the top of my garage which violates code. I could have them place a third pole in the other corner (back yard kind of comes to a point creating three plausible locations) but that's much more expensive than chasing my tale trying to move everything.

I will posts photos as soon as I get home this afternoon. Any help is greatly appreciated.

First off, since u have a divorced meter, the only way to power your garage is by running a feeder into the panel in your house. Sounds like this may be a challenge.

If u do switch to a meter main combo, the house panel will need to be reconfigured into a subpanel which means isolating the neutral bar, adding a ground bar or bars and moving EGCs/grounds over to the new bar(s).

This also means u need a 4-wire feed, which depending on how the panel is fed, may mean running a new feeder. If its individual conductors in conduit, u could just add the EGC. Or if metal conduit, u can use the conduit as the EGC. If its a 3-wire bundled cable such as SEU, then U have to pull a new cable as u cant add separate wires to bundled cables.

Do u really need 200a in the garage? Is it a one man shop? What tools will u be running?

The generator is a whole nother can of worms!