Wiring a GFCI outlet to another GFCI outlet

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  #1  
Old 02-25-11, 08:09 AM
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Wiring a GFCI outlet to another GFCI outlet

I am in the process of completely remodeling one bathroom, and updating a few fixtures in another half bath. These two bathrooms are on opposite ends of a shared wall.

Bathroom #1 (main bath), has one standard three pronged grounded outlet. I will be switching out that outlet with a GFCI outlet.

Bathroom #2 (half bath), used to have a small outlet that was part of the light fixture (remember those?). I updated the light fixture which took away the only power outlet in that bathroom.

Bathrooms are supposed to have GFCI outlets. So, I'll be installing a GFCI in the half bath as well.

Wiring scenario A: Do I run romex wire from the "load" side of the main bath GFCI outlet to the "line" side of the half bath GFCI outlet?

Wiring scenario B: Or, should the half bath GFCI outlet be wired to the "line" side only of the main bath GFCI outlet?

I realize that the half bath GFCI outlet would be double protected by both scenarios, but I'm wondering if either setup would cause "tripping" on the half bath GFCI outlet based only on the wiring configuration?
 

Last edited by ron1999; 02-25-11 at 08:26 AM.
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  #2  
Old 02-25-11, 08:38 AM
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You only need one GFCI to protect all others downline. Yes 2 GFCIs can cause problems.

To be up to current code...I'm not sure the 2 baths can share outlets. Let one of the Pro's wake up and give you the straight scoop.
 
  #3  
Old 02-25-11, 08:52 AM
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You're correct that one GFCI would protect all other outlets down the line. But, the only other outlet, that will be down the line, would be the outlet in the half bath.

And, since bathrooms require a GFCI outlet, I was wondering if wiring a GFCI from another GFCI would cause issues.

A possible third scenario would be to wire a GFCI from the light switch. In this case the GFCI outlet would only be about 10 inches from the light switch (saving me a few bucks on romex wire), and the GFCI would only be hot when the light switch is on.

Since this is my daughter's bathroom I like the idea of her being able to turn off the light which would cut power to the outlet. Just in case she forgets to unplug her hair straightener or something. Lights off, power outlet off, hair straightener off.
 
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Old 02-25-11, 09:05 AM
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If the lights in the master bath are on a separate circuit run the line to the half bath from the line side of the GFCI receptacle in the master bath. Then in the half bath use a GFCI combo switch/receptacle.That way if the GFCI trips it will be in the same bathroom.

If the lights in the master bathroom are on the same circuit as the receptacle you can not use it for the half bath.

A switch in your bathroom to control power for your daughter's room would seem to be very inconvenient for her. Maybe a occupancy switch or timer would be better.

 
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Old 02-25-11, 09:09 AM
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Thanks, Ray.

The bathrooms are on different circuits. I like that idea of using the GFCI combo switch. That would save me alot of time and effort.

I'm curious. Why would a person not be able to use the GFCI combo switch if they had two bathrooms on the same circuit?
 
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Old 02-25-11, 09:11 AM
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See ron...I told you a Pro would be around.
But to clarify...a bath doesn't require a GFCI outlet...it requires a GFCI protected outlet. As Ray described, wiring off the line side of the master, then yes you need a GFCI outlet. I believe he's saying that more for convenience of resetting.
 
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Old 02-25-11, 09:15 AM
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I'll have to work on my terminology. :-)
 
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Old 02-25-11, 09:21 AM
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Vic wrote:
I believe he's saying that more for convenience of resetting.
Yes, that's the reason.
 
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Old 02-25-11, 09:21 AM
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Ray,

I think I misread your entire post. Or, at least I'm not understanding how it applies to what I'm needing.

I wouldn't be connecting a switch in the main bathroom to control the power outlet in my daughter's bathroom.

I think my scenario # 3 confused the issue. So, forget that one.

Let's go back to my other two scenarios.
 
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Old 02-25-11, 09:40 AM
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A possible third scenario would be to wire a GFCI from the light switch. In this case the GFCI outlet would only be about 10 inches from the light switch (saving me a few bucks on romex wire), and the GFCI would only be hot when the light switch is on.
Assuming you already have a constant source of power at the switch in your daughter's room a combo GFCI can be wired so the switch controls both the receptacle and the light.

You could also add another box and receptacle as you suggested or replace the existing box with a two gang box. The light does not need to be GFCI controlled but the switch could controll both receptacle and light.

If you want a duplex receptacle I think the double cang bos would look beter then a second single gang box but that is just my opinion.

 
  #11  
Old 02-25-11, 09:44 AM
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Yes, the light switch, in the half bath, has a constant source of power. That's all the electrical in that half bath. Just a light switch and a light.

So, scenario # 3 would work just fine? I could remove the current light switch, and install the GFCI combo switch, using only the current black/white/ground wires that are being used with the current light switch?

(I don't blame you for rolling your eyes. I just want to make sure I fully understand what you're writing).
 
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Old 02-25-11, 09:54 AM
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See the edit to my last post before deciding.

using only the current black/white/ground wires that are being used with the current light switch?
There are two black and two white aren't there not just one of each?

P.S. Your doing fine. Sometimes I read to quickly.
 
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Old 02-25-11, 10:05 AM
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Yes, there are two black and two white. One set supplying power to the switch, and the other set sending that power to the light fixture. Standard setup.

I was just making sure that, using the current wiring configuration, I could simply remove the current basic light switch, connect the GFCI combo switch, and all would be well?

At that point the switch, of the GFCI combo unit, would provide power to the light fixture when switched on, and the power outlet part of the combo unit would be "hot" and ready to be used, correct?

Or, is the power outlet part of the combo unit supplied with power only when the light switch is in the "On" position?

Either way I like that idea better than running new wire.
 
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Old 02-25-11, 10:18 AM
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It can be wired so the switch controls both or just the light. Tell me which way you want it and I will give you the instructions.
 
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Old 02-25-11, 10:23 AM
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I like the idea of the switch controlling both the light, and the power outlet. That way my daughter can just flip the switch to "off" and if anything is plugged into the power outlet it will be turned off as well.
 
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Old 02-25-11, 10:54 AM
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When you buy the combo device you will find one side has a tab connecting two brass screws. The other side has no tab and has a one brass screw and one silver screw.

Connect the black from the light to the side with the tab.

Connect the black from the constant hot to the brass screw on the side with no tab.

Wire nut the two white wires and a white pigtail together. Connect the pigtail to the silver screw.
 
  #17  
Old 02-25-11, 11:14 AM
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Excellent. Will do. Thank you, Sir.

One more question about GFCI outlets. Is it acceptable to remove a two pronged outlet (no ground), and install a three pronged GFCI outlet (still no ground)?

Would that be comparable, in regard to safety, as a standard three pronged grounded outlet?

Here's my take on what is the safest wiring setup (from least safe to most safe):

1. Two pronged non-grounded outlet.
2. Three pronged grounded outlet.
3. Three pronged non-grounded GFCI outlet.
4. Three pronged grounded GFCI outlet.

Is that correct, or should 2 and 3 be switched?
 
  #18  
Old 02-25-11, 11:34 AM
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A GFCI provides personal safety but no ground path for a surge protector. A sticker that read "GFCI protected, no equipment ground" usually comes with the GFCI and must be used on each protected receptacle.

Yes, even on a properly grounded receptacle the GFCI provides an extra level of protection. Note though the trend is toward AFCI breakers in rooms where GFCIs are not required. AFCIs at this time do provide some GFCI protection but not usually at the level of dedicated GFCI's.
 
  #19  
Old 02-25-11, 11:49 AM
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I won't be using surge protectors. I just want to replace a few of my two pronged, non-grounded, outlets with GFCI's.

This will allow me to safely use three pronged equipment without the time, and expense, of having to run new grounding wires.

So, as long as I'm not using a surge protector (or, did you just mean protection from power surges?) with the ungrounded GFCI outlets, and I make sure they are properly marked (as per NEC requirements), then it should be fine?
 
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Old 02-25-11, 01:31 PM
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Surge protector power strips can be used but they won't provide protection from surges. They will just work like regular power strips with no surge protection.
 
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Old 02-25-11, 01:47 PM
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Okay. Just wanted to make sure you meant using a surge protector and not protection from surges.

Ray, I appreciate all your help today, and the crash course in GFCI's. I'll get it all done this weekend, and my daughter will be happy.

If you lived closer she would probably make you some banana pudding. She makes a mean banana pudding as evident by my ever growing waist line.
 
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Old 02-25-11, 03:21 PM
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Just out of curiosity how would I wire that GFCI combo outlet so that the outlet plug is always hot and the switch activates an appliance?
Put the constant hot on the side with the tab. Put the black from the appliance to the brass screw on the side with no tab. Whites pigtailed to the silver screw.

Appliance will not be GFCI protected. Assumes constant hot at box.
 
  #23  
Old 02-25-11, 03:31 PM
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Thank you, Ray.

I appreciate your help again.
 
  #24  
Old 02-25-11, 04:20 PM
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Note some GFCI switches may not have the tab. If not consider the tab side the side with only brass screws.
 
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