Outside receptacle has no power to it and othe questions


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Old 12-30-08, 11:52 AM
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Outside receptacle has no power to it and other questions

In the last couple of days I have been working to determine what all is on each of the breakers in my house. I have come across an outside receptacle that has no power. Checking the lines coming into the box with a multimeter it shows no power to it whatsoever (measuring to ground). It appears this receptacle is at the end of the line as there is only one cable to it. Everything is finished in that area of the house and I know of no easy way to figure out what breaker it is on so that I can check other receptacles on that circuit. Is my only solution to start checking all the receptacles and lights to find whatever is upstream of the receptacles? This seems like it would be a real pain in the butt. Looking at what else is on the outdoor receptacles circuit that work it seems to make no logical sense on what was put on what circuit as it seems to bounce all over that part of the house. He also included lights on the other GFI circuits.

Here are some other questions I have:
1) The outdoor receptacles are all GFI but none of them use the grounding screw, the electrician grounded to the box only. Is this OK?
2) The outdoor GFI receptacles are all 20A even though the breaker is 15A. The cable coming out of the service panel does not denote the gauge of the wire but comparing it to others the wire out of the breaker is thinner than that coming out of 20A breakers. If the wiring used in the circuits is only rated for 15A it seems a bad idea for the electrician to use 20A receptacles.
3) Multiple GFI recpetacles on the same circuit. Is this OK or recommended?

Thanks for any and all help.

Shawn
 

Last edited by brownsl; 12-30-08 at 12:14 PM.
  #2  
Old 12-30-08, 12:09 PM
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Originally Posted by brownsl View Post
I have come across an outside receptacle that has no power.
Odds are that you have an upstream GFCI receptacle that is tripped. Check the kitchen, bath, garage, basement, crawlspace for a tripped GFCI. Be sure to look in all the places where you didn't even think there was a receptacle like behind the canoe in the garage.

The other highly-likely situation is that the receptacle is powered from a switch somewhere in the house. Perhaps a mystery switch in the kitchen or garage?

1) The outdoor receptacles are all GFI but none of them use the grounding screw, the electrician grounded to the box only. Is this OK?
It can be okay depending on the details of the situation, but the best solution is to pigtail a ground wire directly to the device screw.

2) The outdoor GFI receptacles are all 20A even though the breaker is 15A.
While it's not a huge deal, the receptacles should be 15A instead of the 20A T-slot receptacles.

Multiple GFI recpetacles on the same circuit. Is this OK or recommended?
It is okay. If they are wired to provide downstream protection you may get cascading trips where a receptacle distant from the fault trips.
 
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Old 12-30-08, 12:42 PM
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A forgotten about wall switch in the laundry room was the culprit. Turned it on and now there is power to the receptacle. A bit embarrassing that I did not think about that but much thanks nonetheless! You saved me quite a bit of time and hassle!

Shawn
 
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Old 12-30-08, 12:51 PM
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It's possible this outlet is downstream of a GFCI receptacle outlet you're not yet located.

This is one of the banes of my existence as a home inspector, I carry 100 foot heavy-duty extension cord for those occasions when I test a duplex receptacle outlet in unfinished garage (which is required to be GFCI protected), it trips an upstream GFCI which I then can't locate, and there's a freezer of a with a couple hundred dollars worth of meat plugged into the outlet. I then hook up the extension cord and leave the seller a note explaining the situation - in my opinion I have done them as a favor by discovering the freezer is hooked up to a hidden GFCI!

Hunting down such GFCIs can be a real trial. The usual place to start is in the garage, often they're hidden behind objects stored there, the next likeliest place of the bathrooms, after that it's anybody's guess... I found one exterior outlet controlled by GFCI installed in the corner of an unfinished attic, and though it's not happened to me I've seen pictures posted by other inspectors where an electrician has tracked down an upstream GFCI which had been covered with drywall when the basement was finished.

One other thing to watch for is a GFCI with no receptacle outlets. Some of these are listed by UL for use as a switch (the test and reset buttons on a conventional GFCI are not intended for this purpose) and these are sometimes used to control and protect exterior electrical outlets for Christmas decorations or other "festoon lighting". These can be easily overlooked, especially when the test and reset button are the same color as the body and faceplate they really blend in when they are behind something an you are looking at them edge on.



Fig. 1

----------------

Re the 20A receptacle on a 15A circuit: it depends on whether it is the only receptacle on the circuit, if so you can put a 20A receptacle device on a 15A circuit.

But as all the GFCIs I've seen are duplex receptacles, a 20A GFCI would would not be allowed.

But...

This raises the question" "When is a GFCI a 20A device?"

There are GFCIs listed for "20A" pass-through but which do not accept a 20A polarized plug, and then are 20A GFCIs which do accept a 20A plug:


Fig. 2

as I read the code the first would be allowed downstream of 15A OCPD (breaker or fuse), the second would not.
 
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Old 12-30-08, 01:11 PM
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20 amp duplex receptacles are not permitted on a 15 amp circuit. 15 amp duplex receptacles are perrmitted on a 20 amp circuit.
 
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Old 12-30-08, 04:23 PM
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Originally Posted by thinman View Post
20 amp duplex receptacles are not permitted on a 15 amp circuit. 15 amp duplex receptacles are permitted on a 20 amp circuit.
That's what I said:

1a) The only exception to the receptacle ampacity not greater than circuit ampacity is in the case of a single receptacle circuit:

210.21 Outlet Devices.
- - (B) Receptacles.
- - - (1) Single Receptacle on an Individual Branch Circuit. A single receptacle installed on an individual branch circuit shall have an ampere rating not less than that of the branch circuit.

1b) I've never seen a single receptacle GFCI rated at 20A but if they make one like this 15A combo:



then 210.21(b) would apply, and you could put a 20A receptacle on a 15A circuit.

I know it does not make sense, - it's a code quirk (this gets kicked around on the electrical boards from time to time - everyone starts out certain that 210.21 must specify a maximum ampacity as well, but it does not) - but there you have it.

(Hopefully, the AHJ would refuse to allow it, though they could not cite code to do so).

1c) However, you can't put a duplex 20A GFCI 20A on a 15A circuit.

2) However, there is a second meaning to "20A" GFCI as commonly used: a GFCI that does not accept a 20A plug but which has a pass-through capacity of 20A, here are some examples.

It's fine to put those on a 15A circuit, a GFCI is not intended to function as an over current protection device, and effectively the pass-through function is equivalent to splicing a short length of 12AWG into a 14AWG circuit - or the the same as putting a 20A switch in a 15A circuit.

At least that's how I understand it.
 

Last edited by Michael Thomas; 12-30-08 at 06:05 PM.
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Old 12-30-08, 06:55 PM
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Originally Posted by brownsl View Post
A forgotten about wall switch in the laundry room was the culprit. Turned it on and now there is power to the receptacle. A bit embarrassing that I did not think about that but much thanks nonetheless! You saved me quite a bit of time and hassle!

Shawn
I just troubleshot this same situation for my inlaws over the holidays because that outlet had their roof/gutter ice melt wires plugged in there. Guess this was common in the northern regions? The only reason that I figured it out was that the switch that controlled it was on the bottom of a two-switch single-wide plate that had a red light above it... guessed that red=heat, flipped the switch, voila!
 
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Old 12-30-08, 10:56 PM
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Thanks for all the great information! The receptacles installed must be the 20A pass-through variant as they do not accept 20A plugs. So I guess it is OK.

Shawn
 
 

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