Options for Wiring a small detached garage

[Thompsy]

Hello,
I am new to wiring. I just built a small pole barn (22'x24') and want basic electrical service in it. It is appox 50' from the existing house. I am going to run basic 120v power tools (circ saw, drill, small compressor, etc.) The biggest tool being 15A. I am NOT going to run any larger 220v tools nor plan to.

My house has a 150A Service panel with only 1 single slot left for a breaker.

Can I add in the last breaker (not sure the size 20-30A?) and run 10/3 or 12/3 UF about 50' to the barn? All I want in this barn is a few lights and a few outlets, nothing fancy. I wouldn't need a service panel in the garagebarn would I? Any suggestion?
Thank you.

[joed]

No point in running 10/3 or 12/3 if you only have one breaker slot. You need two full size slots for the 3 conductor to be of any use.
If you can free up a second slot I would run at least 10/3 on a 30 amp 240 volt circuit.

[junkcollector]

If you do as Joe suggests, you will need to install a subpanel, and a grounding electrode. (rod)

If you do not need 240 volts, and 20 amp 120 volt circuit is enough, I would run 12/2 UF-B type cable from the panel to the shed. This will handle the loads you mention just fine, but if it is any length over 50 ft, I would upsize to 10/2. If you think you will ever need more, I would run either 12/3 or 10/3, and just cap the red wire for now. You could later install a 2 pole breaker and have a 120/240 volt multiwire branch circuit.

Where the cable emerges on both ends you will need to protect it, best way is with sch. 80 pvc and an LB fitting. If the trench does not pass under a driveway or such, 18" deep should be good, otherwise 24". You would need to install a 20 amp breaker in the panel. In the shed, you would need a disconnect. In this case an ordinary light switch will serve the purpose. Run the UF there first, then onto your receptacles and lights. Remember that the receptacles need GFCI protection.

Post back if you need clarification on anything.

[Thompsy]

Thanks for the help. So I'll run 10/2 from a 20A breaking in the panel to a main diconnect in the shed(light swithch) from there to 3 lighting and 3 outlet receptacles. So my outles should be GFCI?
Thanks

[junkcollector]

So my outlets should be GFCI?


Yes. You can have the first receptacle be a GFCI and protect all others downstream. Connect the power in to the "line" side, downstream circuit to the load side. You may wish to have your lights connected to the line side, or before the GFCI, that way if the GFCI trips for some reason you are not in the dark. Good luck.

[Thompsy]

Is it the same difference to have a GFCI breaker for the line running to the shed, or have just 1 GFCI outlet in the shed at the beginning of the circuit (everything on load side)? I know the breakers are somewhat expensive....
I've heard that the GFCI's don't last long in an outdoor setting.

Also, I'd be ok running coaxial cable directly next to to the electrical, right?

[suemarkp]

Electrically, they are the same. The design difference is if you feed the whole shed from a GFCI breaker, one ground fault and all power goes -- lights, outlets, everything. With receptacles, you can control what is GFCI'd and what is not. A GFCI receptacle inside an unheated building will last longer than one installed one the outside of a building (heated or not) because of the higher moisture, wind driven rain, bugs, etc.

I'd go with a GFCI receptacle inside the remote shed. You can buy 3 or more for the price of a GFCI breaker.

Running coax cable in the trench with the power is OK. Just don't put them in the same box or same conduit.

[Roger]

A gfci breaker will protect the entire branch circuit to the garage. One advantage to using a gfci breaker is if your trenching manually (shovel) for the 20 amp 120 volt branch circuit the trench only needs to be 12" deep. Otherwise direct bury is 24" non-gfci protected for a 15 or 20 amp branch circuit at the panel. Nuisance tripping is much less now days with the modern gfci's. But be aware it can be a 'pita' to chase a tripped gfci back at the house panel if your in the barn. I prefer a gfci receptacle(s) at the barn then protect what I want on their load side connections as junk and Mark suggested. If you have an entry door you need a light there. A 3 way circuit is nice so that you can control lights at the barn exterior from the house. Just remember this will be a switched branch circuit if you elect to do that. If you had 2 slots or the ability to add a tandem breaker to the single slot left in your house panel then you would be able to run a 3 way to the barn for any external lighting and a second branch circuit for receptacles and lights inside the barn.
It is generally recommended that you keep some degree of separation for com/data cables when in the same trench with electrical. 6 inches probably will be fine.... more is better. Also note that the addition of this coax will require a 4 wire feeder if you elect to install a sub-panel as Joe mentioned.

[Thompsy]

Thanks for suggestions.. Can I run 10/2 UF right from the house service panel? I have about a 25' run before I even get out of the house, and then another 50' to the shed. When I get the UF into the shed I will probably use a junction box to switch over to 12/2 indoor romex, and run one line for lights and then one for outlets.

[junkcollector]

Can I run 10/2 UF right from the house service panel?
You betcha. Type UF can be ran inside just like romex. (NM)

I have about a 25' run before I even get out of the house, and then another 50' to the shed. When I get the UF into the shed I will probably use a junction box to switch over to 12/2 indoor romex, and run one line for lights and then one for outlets.

It is fine to switch over to 12/2. A good place to do this is your disconnect switch. (remember, this can be a light switch, but should be a heavier duty 20 amp version) It wouldn't hurt to put a little tag on the black wire inside the panel in the house saying," 20 amp max breaker." so that no one thinks that they can change it to 30.
Good luck.