Running wire to shed - questions

[Marcus Waddell]

Hey all. Need some advice. Running wire from basement panel about 45-ish feet inside and 65-ish feet underground (outside) to my shed. I measured using a string, so it should be no more than 114' in total (and that is allowing for about 10% overage -- and I draped the string to have at least 2 feet extra at each end). Need at least 40 AMP circuit, but 50 AMP might be nice too. For a 40AMP circuit, according to voltage calculations I need #8 copper wire, for the 50 AMP circuit, #6 copper wire.

Should I:
A) Just buy one 115' (really 125') length of UF-B wire
B) Buy a combo of 50' Romex (aka NM-B) and 75' of UF-B
C) Run 4 separate THWN-2 wires trough conduit
D) Something else

The A or B don't require conduit, but C would. In either case, I would need to rent a trencher, so that cost is not really an issue. Likely ,I'll just dig the whole thing to 24" deep since I'll have the trencher.

Thanks in advance for the help.

 

[Marcus Waddell]

No one has any advice?

 

[Sponsor]

 

[Reach4]

No one has any advice?

Not even one day has passed.

How do you plan to get from the basement to underground? Up and out, avoiding potential leaks, or drill through the basement wall? You need conduit for the up and back down (my preference) , and maybe for through the wall. I am not an electrician.

 

[WorthFlorida]

The type of underground wiring usually is determined by the ground type, distance, elevation, dept of cable or conduit. As Reach stated when any electrical wires goes vertical from the underground it must be in metallic conduit or 80 schedule PVC electrical conduit. In GA your probably on a slab.
Since you are the homeowner do pull a electrical permit for your protection. After inspection there be no problems with any claims from your insurance company and if you ever decide to sell the home, there be no issues from a non qualified home inspector.

Going PVC conduit is usually the easiest and offers good protection. At about 110 ft or more you want to rent a trencher and go down 24 inches from the grade to the top of the conduit. A 1" PVC would be plenty of room for ever wanting to add an additional circuit and using THWN also makes it easy. As a hint, as you glue the PVC together run a pull string or the wire throught each section of pipe before gluing the next piece. While you're at it also drop in a 1/2 PVC electrical conduit for any future low voltage wiring such as for security cameras, alarms, etc. PVC is fairly cheap.

 

[Marcus Waddell]

Not even one day has passed.

How do you plan to get from the basement to underground? Up and out, avoiding potential leaks, or drill through the basement wall? You need conduit for the up and back down (my preference) , and maybe for through the wall. I am not an electrician.

Sorry...usually folks are fast around here.

 

[Marcus Waddell]

The type of underground wiring usually is determined by the ground type, distance, elevation, dept of cable or conduit. As Reach stated when any electrical wires goes vertical from the underground it must be in metallic conduit or 80 schedule PVC electrical conduit. In GA your probably on a slab.
Since you are the homeowner do pull a electrical permit for your protection. After inspection there be no problems with any claims from your insurance company and if you ever decide to sell the home, there be no issues from a non qualified home inspector.

Going PVC conduit is usually the easiest and offers good protection. At about 110 ft or more you want to rent a trencher and go down 24 inches from the grade to the top of the conduit. A 1" PVC would be plenty of room for ever wanting to add an additional circuit and using THWN also makes it easy. As a hint, as you glue the PVC together run a pull string or the wire throught each section of pipe before gluing the next piece. While you're at it also drop in a 1/2 PVC electrical conduit for any future low voltage wiring such as for security cameras, alarms, etc. PVC is fairly cheap.

Got the permit covered. I am on a basement, so getting from the basement to outside is very easy. I already have the Schedule 80 PVC for getting from above grade to below grade (and back). Mainly was wondering about the wire. If I were to run #6 THWN-2 wire, would a #10 ground work? It seems to be adequate from the charts, but wanted some additional insight if anyone has it. Also, is THWN/THHN that much easier to work with than UF??

 

[WorthFlorida]

All wires must be the same gauge. UF is very tough. The sheath takes a very sharp knife to strip it back and not to cut any insulation of the wires. THWN is always easier and conduit. If a wire ever burns or to add a circuit, conduit is always simpler. With UF you would have to retrench. UF is good stuff but I prefer it for short runs.

 

[Marcus Waddell]

All wires must be the same gauge.

Curious as to why? I realize the two hots and the neutral would need to be the same gauge, but what about the ground? Most charts I see show #10 for anything up to 60Amps. Also 8/3 UF is 8 gauge for the red/black/white, but 10 for the ground wire.

https://www.industry.usa.siemens.co...ducts/Documents/Grounding_Conductors_0507.PDF

 

[WorthFlorida]

Yes #10 will work for ground up to #6 conductors. What will be your power needs for the shed? An ARC welder? Are you installing 220? Are you planning to install a circuit panel in the shed? #6 is really a hefty piece of wire.

 

[Marcus Waddell]

Yes #10 will work for ground up to #6 conductors. What will be your power needs for the shed? An ARC welder? Are you installing 220? Are you planning to install a circuit panel in the shed? #6 is really a hefty piece of wire.

It's mainly due to distance and voltage drop. Just running a 50 to 60AMP subpanel to the shed. Then I can put in outlets, lights, etc and if needed, add a welder or a (small) A/C unit.

 

[Marcus Waddell]

Silly question for the group. I'm using 1.5" PVC conduit, how does one transition that larger size into your main panel?

 

[Cacher_Chick]

If you look around you might find a place that rents the tool for making holes in the box. If you have clearance inside and out, you can use a step bit.

If your conduit is bigger than what is required, you can come through the wall into a properly sized junction box and back out in a appropriately-sized smaller conduit to the panel.

 

[Reach4]

Maybe a pull elbow/fitting/conduit body and a 1-1/2 in. Reducer Bushing (reducing bushing)?

 

[Bgard]

I would go with the #6 and conduit, with that distance.

 

[Marcus Waddell]

Thanks all. I figured it out. I looked a little closer at my main panel and noticed that there are what I would call "regular" sized knock-outs (for 3/4" connectors), but there were also a few stepped knock-outs that can do 1/1.25/1.5/2 inch connections. So I used and "LB," a male adapter and a bushing. Worked like a charm.

 

[Marcus Waddell]

Thanks to everyone for your help! I did all the work and passed the final inspection. Much appreciated.