There are three reasons I can think of to have GFCIs at each location.
1. If you have only one GFCI and water gets into one of the downstream
outlets, you have no idea where the water is that is causing the GFCI to
trip. I've seen this twice. I have outlets around the outside of my shop
that are all on one GFCI. I've been trying to figure out where the water
is causing the GFCI to trip in a heavy rain. As soon as I can, I am
going to rewire things and replace all the outlets with GFCIs. The
second place I have seen this problem is on a Habitat for Humanity job
site. There are 4 GFCIs on the power pole, with numerous extension cords
and splitters heading out all over the site. All of a sudden some of the
cords loose power. It can take 5 minutes to follow all the cords and
find the one that got wet.
2. If water gets into the wire underground, and you have a single GFCI,
it can cause the GFCI to trip. If that leakage (Very small) is before
the GFCI, it will not cause the GFCI to trip.
If you have only one GFCI and manage to trip it while using the farthest
outlet from the GFCI, you have to walk all the way back to the single
GFCI to reset it. This may not be a problem, but if you have an outlet
hundreds of feet away, across a fence, around a building..........., it
can be a real pain.
Peace,
Pat
cornerexit wrote:
>
> Tim,
> I understand the master gfci concept, I used exactly that in my shop.
> However, it has been recommended to me to put gfci outlets at all
> points in an outdoor/wet situation. I don't know what code says about
> this, but I only had to buy one 20amp gfci outlet for this project as
> I had some left over from the shop build.
>
> I probably didn't explain the situation good enough. The run does
> indeed go "out" to a receptacle then branches out. One of those
> branches needs to come back towards the house in the same ditch for a
> short distance then makes a turn into another trench which leads to
> the next outlet. Rather than put yet another trench in I can use just
> a little more cable, but have to tear up less yard with more trenches.
>
> Wayne
> ----- Original Message ----- From: "Mullen, Tim (IIS)"
> <Tim.Mullen@ngc.com>
> To: "cornerexit" <cornerexit@gmail.com>; <shop-talk@autox.team.net>
> Sent: Monday, September 12, 2005 8:37 AM
> Subject: RE: Direct burial cable
>
>
>>
>> First, why not get a single GFCI plug as the first outlet on the
>> circuit, and then run all the others from it? Some GFCIs are designed
>> to act as the "master" for all the "downstream" outlets.
>>
>> Second, why would you run a circuit "down and back'? Why not run the
>> circuit to one box, and branch out in two directions? The outlets
>> should all connected in parallel, not series (except the first GFCI), so
>> why run twice as much cable as needed.
>>
>> Tim Mullen
>>
>> Chantilly, VA
>
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