Add GFCI to outdoor receptacles

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  #1  
Old 11-27-15, 09:44 PM
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Add GFCI to outdoor receptacles

I'm trying to figure out which option I want to use to handle this little situation, before the wife divorces me for not getting it done.

We have two single gang boxes with 15 amp receptacles on the front of the house. They are currently both on a 20 amp circuit, wired up with 12/2 NM-B into a weatherproof "wet location" metal box. The box is set into the siding and not on top of. The receptacles are grounded to equipment ground, but the boxes themselves are ungrounded. The boxes are covered with "wet locations with covers closed" type covers. I want to add proper GFCI protection and in-use covers for safety, mostly for the holiday season when lights are plugged in all the time.

Here are the problems: 1) Each box has its own separate run from a J-box in the basement, so if I were to add GFI receptacles I would have to do it at each box. I can't wire up a downstream device. 2) The metal boxes have a hole for a ground screw, but my ground screws won't thread in. First time I've had that happen . 3) The charming individual that did the previous work left me about 2 inches of wire to work with in the box. 4) Even with so little wire left, the current boxes are too shallow for a GFCI receptacle to fit properly .

So I'm considering three options: 1) Start fresh with a new box, new cable run, new everything. 2) Replace the breaker with a GFCI breaker to protect both outlets, add an in-use cover, and try to find a place to attach a grounding pigtail with a clip in the metal box. 3) Add a weatherproof box extension and a new GFCI receptacle. Will still have to find a place to attach a grounding clip, and may have to splice the existing conductors to then be able to reach the new receptacle. Not sure.

Thoughts? I guess I'm leaning towards option 1, despite it being more work. Thanks in advance!
 
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  #2  
Old 11-28-15, 06:06 AM
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While using the grounding screw is prescribed, most GFCI receptacles are self grounding. GFCI's don't necessarily rely on the grounding wire for their operation, as they detect the difference of current between the hot and neutral and trip when an imbalance occurs. Check your GFCI of choice to see if it is self grounding or not. That will save you a bunch of time. Otherwise, you can pigtail the wires in the box, giving you adequate wire to work with. A grounding clip probably won't open sufficiently to hold on a WP box as it will in a regular wall box. Using a GFCI breaker will solve the problem, but create another one when the receptacle trips it. You will need to go to the panel to reset is. Minor inconvenience, but doable.
 
  #3  
Old 11-28-15, 07:21 AM
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I would favor #3, using an extension ring on the box, although it may be difficult to find one that fits and is suitable for outdoor use.
 
  #4  
Old 11-28-15, 08:29 AM
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While GFCI's do not require a ground to operate, they are not self grounding and are required to have a ground wire attached where available. There are kind of self tapping ground screws out there that have a small cut in them to help them thread into a box, or you can just drill and tap your own hole. I use these which work well: SAE Drill/Tap/Deburr Bit Set 13 Pc Use the 10-32 drill/tap.

The screw on the top is the tapping one:
http://www.engproducts.com/wp-conten...und_screws.png

IMO - I would rather have the GFCI inside instead of outside. I would install a 4x4" box next to the panel and install a dead front GFCI device, or GFCI receptacle, and protect the circuit that way. The circuit would come off the breaker, to the box/device, and then go to the outdoor receptacles.

These will help for extending the wires in the boxes: http://www.idealind.com/prodDetail.d...v=0&l1=push-in
 
  #5  
Old 11-28-15, 09:55 AM
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Just to clarify, the receptacle currently is connected to the NM cable's grounding wire. It's just the box that's not grounded. If the self-grounding receptacle would take care of grounding the box, I can get one of them.

I guess the only problem I see with moving the GFCI inside, either to the panel or to a dead-front GFCI, is that I then wouldn't have a self-grounding receptacle and I go back to the issue of how to ground the box, right?

Also, if I do put an extension ring such as this Bell 1-Gang Weatherproof Extension Ring-5406-0 - The Home Depot on the box, it creates a weatherproof seal between it and the old box with a gasket. Would that gasket then insulate the extension from the original box, meaning that only the extension is grounded via the self-grounding receptacle?

I'm using these grounding screws: Grounding Screws Ideal claims they're "thread forming," but of four screws I tried, the threads just smashed down on them. Might look for another brand of self-tapper.
 
  #6  
Old 11-28-15, 10:02 AM
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Standard self grounding receptacles are easy to find, while self grounding GFCI's are not. They will have a small metal clip the ensures a connection between the strap and the screw.

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I have also listed other ways to bond the box above. I would just drill and tap a 10-32 hole.

The extension ring you posted would not make any type seal while a standard in-use cover would.
 
  #7  
Old 11-28-15, 10:11 AM
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So if the extension ring doesn't create a seal between it and the existing weatherproof box, then the whole assembly is no longer weatherproof and therefore no good for outdoor use.
 
  #8  
Old 11-28-15, 11:05 AM
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It will seal on another box, I don't think it will seal to the siding of the house.
 
  #9  
Old 11-28-15, 11:53 AM
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Correct, I would seal it to the existing box, making a deeper enclosure to fit a GFCI receptacle.

What I'm concerned about is, does the gasket that forms the weatherproof seal between the old box and the extension ring act as an electrical insulator and interfere with bonding? In other words, I attach the extension ring, install a non-self-grounding GFCI, and attach grounding pigtails to the receptacle and the original box. Is there the possibility that the extension ring can then become live and not properly ground out? Does the extension ring need a separate pigtail to it? Or do the screws that attach the extension ring to the original box create enough continuity for it to ground out?

In other words:

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  #10  
Old 11-28-15, 01:51 PM
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All GFCI's that I have installed have been self grounding.

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  #11  
Old 11-28-15, 04:08 PM
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I can honestly say I have not seen one like that. Are they listed as "self grounding", or just "grounding" or "grounded"?
 
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Old 11-28-15, 04:30 PM
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Listed on advertised site as self grounding. Leviton's.
 
  #13  
Old 11-28-15, 05:46 PM
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Those aluminum weatherproof boxes are designed to take a self-tapping grounding screw. They cut their own threads when turned in with a nutdriver.
 
  #14  
Old 11-29-15, 05:15 PM
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Ok, I think I've got what I need to make it all work now.

So one final stupid question. The receptacle I picked up, the ground screw seems to have a clamp under it. I'm used to just putting a 2/3 turn of wire under a screw and tightening it down, but this one seems almost to be saying "insert a wire under me." What's up with this? I can also give it a tap and the "clamp" settles back down and I could just wire under the screw too.

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  #15  
Old 11-29-15, 06:22 PM
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Yes, just as the hot and neutral areas "capture" the straight wire, so will the grounding screw. No need to form a shepherd's crook.
 
  #16  
Old 11-29-15, 07:46 PM
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The ground will insert under the clamp. Just strip and insert.
 
  #17  
Old 12-03-15, 12:54 PM
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Ok, so the electrical gods hate me.

I got an extension ring, and the ring itself seals fine, but the screw holes don't line up to attach it to the old box. I'm guessing the old box was under some kind of older design spec.

On to plan B: Replace the receptacles with TR/WR self-grounding non-GFCI receptacles and in-use covers, and provide GFCI protection from inside the house. The easiest way would be to either add a blank-front GFCI and wire the outlets from the load terminals, or a GFCI breaker, as we talked about.

Now, here's the question. The three receptacles on the circuit are all wired together in a junction box now. I've looked in all the reference materials I have and I can't find this specific situation addressed. Can I do this?

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Will it provide GFCI protection to all the downstream outlets this way? And will it cause nuisance tripping?
 
  #18  
Old 12-03-15, 02:31 PM
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As long as the load terminals feed the receptacles they will be protected.
 
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