Running a 20 amp circuit to a shed

[BRULEDRIFTER]

How deep does the trench need to be? I believe that there is one depth for wire in conduit and one for just buriable wire?

I need to run 80 feet, will 12 gauge wire be enough? Just one outlet and a motion light.

[JohnMickish]

Need more information.

Are you going to be on a GFCI breaker or GFCI protected circuit or an a regular breaker?

If you are going to put it on a GFCI breaker and use UF wire the trench has to be NO LESS than 12 inches deep.

[MuleShack]

When i ran a line out to my building it was a 20 amp with a seperate box with GFCI and they enclosed the wire in a tube and we made it 36". Of course we were running gas line also and that was in a seperate trench at 36"...so maybe thats why we put both at 36".

[PierBridge]

Find out what the Code is and do it right!

[fastkaw]

As said, check your codes.

Where I live it has to be down 18in.... I would run it in pipe that way you can always

upgrade. Also a little more shovel prof. Make a map with locations on it.

If you are going to put spotlights in you fixture and a 80 foot run, you

better stay with 10ga. wire.

[BRULEDRIFTER]

Need more information.

Are you going to be on a GFCI breaker or GFCI protected circuit or an a regular breaker?

If you are going to put it on a GFCI breaker and use UF wire the trench has to be NO LESS than 12 inches deep.

[fishingishot]

You better get right on it if you are planning to get it done yet this year. Depending on your soil type most times homeowners and do it yourselfers will use UF cable because of cost and ease of installation. Depending on where you picking the up from you may not need to add a GFCI receptacle or breaker. If the circuit is not GFCI protected already you will need to add either a GFCI breaker or GFCI receptacle. You will find breaker cost of $30.00 and receptacle cost $5.00.

If I was doing what you say it would be 12/2 UF w/ground direct buried and a GFCI receptacle.

UF Cable minimum of 24 inches. Unless covered by 2”-4” of concrete.

PVC Conduit minimum of 18 inches.

[rattlem'up]

fishingishot is definatly on the money. Any of those uses would be acceptable. But i would still looking into it further. As some city codes may differ.

[JohnMickish]

The NEC (National Electrical Code) article 300.5 states that;

Residential branch circuits rated 120 volts or less with GFCI protection and maximun overcurrent protection of 20 amps you need to be 12 inches deep.

You will need 18" if you are running under an airport or adjacent areas but not in your backyard. You will also need 18 inches if running UF wire in places that are not residential, but, and I repeat, article 300.5 states that for residential use, 120 volts or less and GFCI protected, 12 inches. You can get by with 6 inches deep if you want to put it under 2" or concrete if you want to.

In the residential column, the only places you need to be more than 12" is under streets, road and such or airports, neither of which fit into this particular project.

Thats the issue I have with the code book and not knowing how to read it. I've said it before and I'll say it again. Not all rules apply to all situations. What someones cousin did in their shed dosen't mean the same rules will apply to the bathroom in a church. Without knowing exactly what it says and how to read it, no advice is better than bad advice.

10 ga wire would not be the way to go for this application, heres why. You are allowed 3% voltage drop, by code. 12 ga UF wire will excede 3% at a 12 amp load. With 10 ga wire you will be at 3% with a full 20 amps.

[JohnMickish]

If I was doing what you say it would be 12/2 UF w/ground direct buried and a GFCI receptacle.

UF Cable minimum of 24 inches. Unless covered by 2”-4” of concrete.

PVC Conduit minimum of 18 inches.

Where are you getting your information? 18" for PVC is under driveways, not backyards. If you are looking at 300.5 look at column 4. Column 4 is for residential, column 1 is direct bury cables (UF) and column 3 is nonmetalic conduit (PVC). This application falls into column 4

The advantage of going to the breaker is that the circuit will be dedicated and for lack of a better term, all of the electricity in the circuit will be available for you. If you tie into the load side of a GFCI receptacle it will still be 100% legal but you will have to share the power with other items.

[Roofer]

Is it worth it or not? That is the question. Go to your rental center and rent a trencher. Put it as deep as the trencher goes (usually about 3 ft. or so). This will cost you about $100. The wire will be another $100-$200, and then get an electrician quote. For a small job they will probably charge you a little more than usual. This will cost you at least $400.

I think this is the initial answer you were looking for. If you want to tackle it yourself, there is some good advise here, especially from the electricians here.

[Roofer]

BTW, frost does break wires, so make sure it is deep and loose.

[JohnMickish]

Roofer dude,

I'm just stating what it HAS TO BE, as in the minimum. The NEC tells you the minimum required. Heck, if you want to you could put it in rigid pipe, encase it in 4" of concrete and run 500MCM wire out there if you want to. That would be legal too.

[Roofer]

Didn't mean anything by it mnfishinguy. I know that you know your stuff and I'm sure it is well appreciated by many.

[JohnMickish]

I wouldn't say "many" It's an interesting book, I recomend it to anyone needs to go crazy. It would be nice if more of the codes "where across the board" but then agian, that's what they pay me for, is to know when to apply what rule to what situation.

[Jim Almquist]

I wouldn't say "many" It's an interesting book, I recommend it to anyone needs to go crazy. It would be nice if more of the codes "where across the board" but then again, that's what they pay me for, is to know when to apply what rule to what situation.

I would like to have a dollar every time they say "shall and shall not"

[BobT]

There can be other questions as well. Will you be running under an area where vehicles drive? If so, code is different.

Bob

[JohnMickish]

Bob is right, I asumed a regular backyard.

[BobT]

Roofer dude,

I'm just stating what it HAS TO BE, as in the minimum. The NEC tells you the minimum required. Heck, if you want to you could put it in rigid pipe, encase it in 4" of concrete and run 500MCM wire out there if you want to. That would be legal too.

I can't help but poke a little fun here.

It would be legal if the circuit components could handle the 500MCM. I'm thinking it would not be legal to use it to supply a 30A panel.

Bob