Electricians?

[Limited-Time]

Getting ready to run power to the dock. It's a 200 foot run from the box. I want to run a 20 amp service, with either a GFCI breaker or GFCI outlet. I'm leaning towards the outlet, so I won't have to walk up to the house every time it trips. Any thoughts?


I also need to know what gage wire to run; I figured 12 gage should do it. Additionally, what is the designation of the direct burry romex(sp)? I want to make sure I get the correct type. Thanks.

 

[rwise]

Re: Electricians?

going 200' or so I would run at least 10g wire (EDIT: see the calc below, 10g is not big enuf) as you will get lose due to the distance, direct burial is what I ask for when going that way, but I aint done any wiring in 15 years

 

[KnottyBuoyz]

Re: Electricians?

Getting ready to run power to the dock. It's a 200 foot run from the box. I want to run a 20 amp service, with either a GFCI breaker or GFCI outlet. I'm leaning towards the outlet, so I won't have to walk up to the house every time it trips. Any thoughts?

The GFCI should be the first outlet on that circuit. If you've dedicated a circuit for the dock then you should be ok. If you're taking the 20amp lead off of another circuit with an outlet then that first outlet should be the GFCI.

 

[SS MAYFLOAT]

Re: Electricians?

I agree with Richard on this one. 10 awg (copper) direct burial is the way to go for that distance to allow for the voltage drop. It would also be a good idea to sink in a grounding rod by the dock. This would help insure an extra step of safety.

 

[Pascal]

Re: Electricians?

I don't profess to being an electrician but I do know that you want a max of around a 2% voltage drop at the farthest load. The chart I've used shows that a 200 ft run needs at least a #4 conductor to provide that. Just to be sure, there are calculators on the net like this one. http://www.cerrowire.com/default.aspx?id=48


A #10 wire looks like about a 8-10% voltage drop.

This chart shows the #4 for a 200 foot run and a 20 amp load with a 3% max drop. http://www.cerrowire.com/default.aspx?id=51

 

[CalicoKid]

Re: Electricians?

A 20 amp circuit would be good for a 16 amp load or 80% of circuit capacity. I'd go #10 also and the cable designation is UF. If you are going to dig a trench all the way down then consider putting PVC conduit in rather than burying the UF and pull in THHN wire to a junction box at the dock. That way you can upgrade or add circuits if needed in the future and add switched lighting circuits and all that fancy stuff people always wish they had done. When we do docks we trench 24" and bury a 3/4" to 1-1/4" conduit depending on the size of the project. Sometimes we put in a pair of pipes. Rarely will we bury UF cable anymore unless it is just a postlight in a yard or something very simple.
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[bassboy1]

Re: Electricians?

Direct burial is nice, but at my house we always put it in conduit. Usually direct burial in conduit. You never know when someone is gonna go crazy with a garden tiller, or a dog is gonna dig into it. I would recommend putting it in gray plastic conduit.

 

[burroak]

Re: Electricians?

Getting ready to run power to the dock. It's a 200 foot run from the box. I want to run a 20 amp service, with either a GFCI breaker or GFCI outlet. I'm leaning towards the outlet, so I won't have to walk up to the house every time it trips. Any thoughts?


I also need to know what gage wire to run; I figured 12 gage should do it. Additionally, what is the designation of the direct burry romex(sp)? I want to make sure I get the correct type. Thanks.

Just my $.02, put the GFCI in the house load center and size the wire and breaker to handle the load and more. The GFCI will protect against the stray incursion (no matter how slight the chance). If you make too many trips to reset the GFCI, you know what that means, right?

 

[Rancherlee]

Re: Electricians?

I personally would put in the brakers instead of the outlet style. And it must be buried 24" or more unless its in PVC or under cement then 12" is ok. When built my house last year I had to also bury a red "warning tape" 12" above the wire so if someone ever digs there they hit dig up the waring tape first. I don't think the warning tape is required on a 20amp or less run YET.

 

[rwise]

Re: Electricians?

Pascal I like the calc. that would have helped a lot back when I did that kind of thing. But they could improve on it. THHN is good insulation butwill melt under a rated overload that the same wire with silicon/glass brad would handle. Also solid/stranded makes a dif.

LT if you use conduit and pull wire through it, over size it and pull in a small nylon rope or two for future pulls.

I like to pull oversized wire, less loss and more room for the "oh sh!t" I forgot,,,,or now I want,,, if $'s allowed it would be nice to run say a 50 amp service (1awg by that calc above with a 2.5% loss (3 volts)) to the dock and break it down at the load end.

 

[Pascal]

Re: Electricians?

I like the suggestions for direct burry shielded cable (external shield/ground) and the tape is good for a warning to anyone digging too near the bury. I?m not that familiar with the insulation specs. I guess there is a lot of ways to ?git er dun? just depends on the expectations in the end.

If you make the 200 ft run from a breaker in the ?house? to the outlet at the dock with undersized cable, you may experience the frustration of blowing the house breaker with loads at a small fraction of the breaker capacity. I was running a ?huge? 14 gauge, 60 ft extension cord to my shop from the outlet on my deck. I couldn?t even rip a sheet of 3/4? plywood with out tripping the breaker in the house and it was a new breaker.

I would make the cable run terminate at a small breaker panel at the dock and have that feed the outlets/circuits that you need with smaller gauge. Put the GFCI in the sub panel if you pick the breaker method over the individual outlets. That is what I did with my shop. The cable bury is a #2 for a 40 foot run from a 50 amp breaker in the house to a panel with a 100 amp main and 8 circuits used in the panel. The 100 amp panel was used because it was a good buy and had lots of room for circuits but it is basically just a shut off switch. I?ve never had a problem with breakers blowing even with 4 - 2?x 72? belt grinders plus lights and drill presses running at the same time but you likely don?t have those load expectations most of your concerns have to do with the 200 ft length of the run.

 

[Bindernut]

Re: Electricians?

200' run for a 120v 20A circuit...I'd go with #4 like the chart that Pascal linked to. 10ga is too light, you'll only have like 15-16A capacity on it at the end of your run.

You better check eith any local codes you've got. A GFCI at the breaker panel may be required if within XXX feet of a wet location...or maybe just a GFCI outlet will suffice.


Personally, I'd tap off the main service with standard breakers, run underground through conduit with THHN, put a sub-panel at the end of run with GFCI breaker, then tap off to the outlets. And yes, sink a ground rod at the end of the run for added protection. Upsizing the conduit and pulling a snake twine or two for future expansion might not be a bad idea either.

If all you want is a small power post near the dock, you could do just the breaker at the house and GFCI outlet(s) in a weatherproof outlet box @ the dock. Still, don't skimp on the size of wire on that long of a run.

Check your local codes first! My post assumes that your state is like ND...an wner can still do their own electrical (as long as it passes inspecton afterwards).

 

[flashback]

Re: Electricians?

not being an electrician, I don't know the terminology but I think the braided or twisted copper wire made from many small strands would carry the load better... just a guess but I think the electricity travels on the surface of the wire and many small strands have a lot more surface area than the standard type wire in a house...

 

[Bigprairie1]

Re: Electricians?

....Calicokid and Pascal have got game here. I would go with heavier guage tho' than #10, particularly at 200'. I don't know if #4 if needed.
#6....#8 maybe.
I would go with a GFI breaker at the main panel AND a GFI plug at the dock. Don't putz around....someone is going to pay.
We have a 24" burial code around these parts...which hurts...thats a lot of diggin'. If it isn't a vehicle accessible area....we can get away with 18" and still be 'code'.
I definitely would put the wire through a conduit tho' probably a 1". If you ever have a problem or someone ever calls you on it...you can always fish a bigger wire through it to make amends. If you direct bury the cable and it doesn't work out....get ready for a 're-dig'.

 

[bassboy1]

Re: Electricians?

I definitely would put the wire through a conduit tho' probably a 1". If you ever have a problem or someone ever calls you on it...you can always fish a bigger wire through it to make amends. If you direct bury the cable and it doesn't work out....get ready for a 're-dig'.

That means leave a pull through cable in the conduit when you install.