Detached Garage, EV charging

[growler]

I looked at a job yesterday to bring power to a detached garage. Also to finish electrical rough but that wouldn't be a problem.

There are two choices, first to bring power from the house but that would require a lot of trenching to get around to the back of the house and the panel doesn't have correct working clearance (inspector may not like that), don't think there would be capacity for future charger and county may have them install smoke detectors in the house if it's considered a major addition.

The other choice is a seperate service that would be kind of easy and would provide power for future charger and the inspector would never get inside the house. There is a minimum charge just to have a meter for the seperate stucture each month and this would be more than power used.

I'm thinking that a seperate service may be the way to go even though I normally wouldn't. It would certainly look like over kill to have a seperate service for a couple door openers and a few lights and receptacles but with all the electric vehicles these days.

Do most of you offer a seperate service as an option for cases like this. Be easy as the transformer and pole are really close. Simple overhead, little 100 amp. Who knows they many end up with more in that detached garge than they are willing to admit now. It's kind of a large structure for a 2 car garage.

 

[jaggedben]

In my opinion the NEC would only allow a separate service for this application one of the following conditions:

1) There is currently no power to the garage and/or you move all existing circuits at the garage to the new service
or
2) the EV is to be put on a meter with a different rate schedule (which is not at all unheard of).

See 230.2. You can only have two services to a building for certain reasons.

As far as whether it makes more sense, sounds like possibly it would, but really depends on all the details.

 

[infinity]

I would go with the separate service option since it sounds like you don't want to add a big load to the existing service which also may keep them from needing to upgrade the existing service in the future.

 

[growler]

In my opinion the NEC would only allow a separate service for this application one of the following conditions:

1) There is currently no power to the garage and/or you move all existing circuits at the garage to the new service.

There is currently no power to the garage. It's in the process of being built. Seperate structure. Needs electrical inspection before sheetrock.

The original GC has been on the project for over a year and the homeowner is trying to terminate the contract (if one exist) and get his own permit and finish the job.

 

[Fulthrotl]

2) the EV is to be put on a meter with a different rate schedule (which is not at all unheard of).

i've heard of it twice. i had to put in a separate meter to a garage in costa mesa a few
years ago, as he was getting a different rate to charge the car.

$2000 to put in a dedicated service for an electric car... wonder how long it took for the
savings to break even on that one..... :dunce:

 

[growler]

i've heard of it twice. i had to put in a separate meter to a garage in costa mesa a few
years ago, as he was getting a different rate to charge the car.

$2000 to put in a dedicated service for an electric car... wonder how long it took for the
savings to break even on that one..... :dunce:

Some communities/cities here have offered a rebate or tax break just own an electric vehicle and install a charger. They don't even ask for seperate metering.

 

[Fnewman]

A second service for an outbuilding is pretty common in our area, particularly when the anticipated loads are significant. Otherwise it is pretty much an economic decision, based on the applicable rate schedules.

 

[retirede]

A second service for an outbuilding is pretty common in our area, particularly when the anticipated loads are significant. Otherwise it is pretty much an economic decision, based on the applicable rate schedules.

Here we pay about $35 per month "facility charge" just for the honor of being connected to the grid. Makes second services uneconomical for homeowners. A second meter for a reduced rate (for heat pumps, usually) is not subject to a second facility charge. A second service to a detached structure would be.

 

[growler]

Here we pay about $35 per month "facility charge" just for the honor of being connected to the grid. Makes second services uneconomical for homeowners. A second meter for a reduced rate (for heat pumps, usually) is not subject to a second facility charge. A second service to a detached structure would be.

I think the "facilities charge" or whatever they call it with this POCO would be a little less than $35 a month, used to be around $25. But it still adds up in the long run of say 10 years.

If they never use anything but garage door openers and a couple of LED fixtures it a waste of money.

On the other hand if they ever have to upgrade the service of this house for a EV charger or any other equipment then it's really going to be expensive. Their electrical system is a real mess.

I have not herd back from the homeowner that he was able to transfer or cancel out the original building permit and get one in his name so I'm not sure that anyone can even work on the project until they get the paperwork cleared up.

 

[drcampbell]

... $2000 to put in a dedicated service for an electric car... wonder how long it took for the savings to break even on that one ... :dunce:

Faster than you might guess. Plugging in a few numbers:
20 kW·hr five days per week
10¢ savings per kW·hr due to EV or time-of-day tariff
$2k savings accrue in 200 weeks. (four years)
(your tariff may vary)

As for the original question:
If there's no EV charger in the immediate future, it'll be almost impossible to justify a separate service. Dig a trench and put in a conduit big enough to accommodate the EV charger, even if it's only used for a single 15-amp circuit now. You can deal with the service upgrade later, when there's actually an EV to be supplied.

 

[samadam]

I know our local utility and AHJ only allow one service per residential address. I have customers in the past that the garage forced a service upgrade on them. I would also make sure the EV vehicle charging needs. We have installed 50 amps for a Tesla and 20 amps for a Ford C-max.

 

[just the cowboy]

Tax issue

Tax issue

A guy I work with had a separate service installed in hisgarage, Come tax assessment he was assessed for commercial because of the sizeof the garage with “A SEPARATE SERVICE”. So have him check everything out, I would not of wanted to be the one to recommend it.

 

[growler]

Dig a trench and put in a conduit big enough to accommodate the EV charger.

That was my first thought also. Once I looked at the panel location I change my mind. Panel is located in the middle of the house on the ground floor. It would be hard to get out of the panel with a circuit now but because of other remodeling it would be possible. Once they close up the last of the sheetrock it will be impossible to add any more circuits without doing lots of sheetrock cutting and repairing. Whatever gets added to the panel gets added now for all practical purposes.