New electrical circuit - requesting assistance

[Jim Joyce]

I've evolved to thinking UF-B 10/2 (with 10ga ground) will work for this application. I would bury 120ft of the 150ft roll, which gets me from the exterior of the house to the interior of the shed. Once inside the shed, I can use the scrap UF (about 30 feet or less left over) to run to receptacles and then some 12ga to run to lights. At the house, I'm leaning toward using a 20A GF/AF breaker ($40-$50) versus a standard 20A breaker ($4).

150ft of UF-B 10/2 10ga

Dual Purpose Arc Fault / Ground Fault 20A Breaker

(Just an example, not necessarily what I'll buy)

Good. I plan to rent a trencher so this is not a manual dig.

10ga is sounding like a good choice.

I like all of that.

I've never worked with UF, but after doing some reading today, plus what all of you guys are saying, I'm more comfortable with it now.

[Jim Joyce]

30+30+40 is right. It's unlikely that everything would be drawing power at the same time, but it's possible. There's nothing left available for the shed then. Hmmm...

On the home improvement shows, when a breaker panel is fully populated and they need more breakers, they swap the panel for one with more capacity. I suppose that's always an option.

(snipped lots of good info) Thanks for all of that.

[Jim Joyce]

Excellent, thanks. I'm with you on avoiding the spring loaded back stabbers.

[Jim Joyce]

Agreed. I may not have said much about that but it's sort of what I was thinking. Thanks.

[Jim Joyce]

I actually started out thinking I wanted solar, but I'd have to hide it from the HOA. They have a strict rule against it, saying it negatively affects property values, in their opinion. Fortunately, the south side of the roof shed faces away from the street and is all the way in the back yard. But here we are, abandoning solar in favor of AC.

[gfretwell]

If that is the case and you don't hit "ledge" or some other solid obstacle I would go as deep as is practical (up to 24"). Nobody ever got it trouble being too deep. Get a stick of 1" RNC (gray PVC) to protect the cable as it comes out of the ground and 2 gray boxes to make the turn into the building. Pack the pipe with duct seal around the cable so ants don't have a tunnel into the box. You could use "LBs" (conduit bodies) but boxes will let you add additional outdoor receptacles on that circuit. Pigtail the connection with wirenuts. Don't use the device as your splice.

[Bod F]

As long as you're trenching, two 1" conduits minimum, one for power and one for telecom.  And since a shed is a good place to run a generator, consider adding a generator circuit as well.

[Ed Pawlowski]

What kind of lights are you putting in that you need 12 ga? Must be powerful spotlights or airport tower. Much easier working with 14 and meets code.

I know you want to use the leftover 10 for the receptacles but 12 is easier to work with too.

[trader_4]

14 gauge doesn't meet code for a 20A circuit, which is what he says he's running, but 12g does and I agree that's much better than running 10g.

[dpb]

On 11/21/2019 8:20 AM, Ed Pawlowski wrote: ...

The paltry few bucks saved will _NOT_ be made up for by the pita factor in using 10 in the boxes, agreed.

And, I'd also say that the few $$ difference between 10/2 and 10/3 isn't enough to not go ahead and bury the 3-wire so you have the option for

240V available if needs/wants change down the road.

What meets code depends on what breaker size install, though...isn't it still required to run 12 if use 20A even tho lights portion of the circuit now w/ LEDs won't ever come close?

[Ralph Mowery]

The real thing to do is not to be so cheap. Run # 10 wire to the building with a 30 amp breaker, put in a breaker box with some 20 and

15 amp breakers. Then Run # 12 and 14 wires where needed. The # 12 is hard enough to work with in some boxes.

All wires have to be sized large enough for what ever breaker feeds them. If you have a 20 amp breaker, you have to run atleast # 12 even if it is just to a 7 watt night light.

[Scott Lurndal]

As was pointed out, the breakers for those loads are sized for worse case loads. Consider the stove/oven, once it reaches the target temperature, it cycles on/off as necessary. Even if you have all four burners on and are warming up the oven, it won't draw the full 40 amps listed above continously.

Same is true for Dryer and HVAC.

[Scott Lurndal]

No, the leviton devices are not called back-stabbed because they aren't. Back-wired use screws for the connection - back-stabbed have springs that catch on the wire and hold it in. I believe that these (back-stabbed) are no longer code compliant.

[gfretwell]

It won't be horrible if he wirenuts the #10, pigtails some #12 on to go to the devices and shoves bulk of the wire in the back of the box.

[gfretwell]

They are still listed but limited to 14ga wire.

[trader_4]

With 240, even if he does not need it, it would allow an Edison circuit, so he could get TWO 120v 20a circuits, with the same 20a limit. All depends on what might be done with the shed. It certainly does not add much to the total cost.

That's my understanding.

[Barb]

What you believe is not relevant or useful.

[Jim Joyce]

It's a 4ft LED shop light. The specs say it draws 35 watts. :-) So yeah,

12ga is overkill.

Agreed.

[Jim Joyce]

I was thinking 10/3 UF is almost double the cost of 10/2, but I see that I was probably mixing some 8/2 into that research. 8ga ratchets up the cost, compared to 10ga, especially 8/3. I've abandoned the idea of 8ga, though.

Understood. Thanks, everyone, for the reminder.

[micky]

Maybe that's because the Code is opposed to violence?

I note that there are no electical connections called shot, and ftm that Quaker Puffed Wheat is no longer called "shot from guns".

I have long been opposed to violence among electrical devices and cereal.