Thread: First Receptacle

You can protect receptacles down stream by using a GFCI device at the first receptacle. Is there a quick way to determine which is the first receptacle? I've done it by trial and error, but was wondering if there is a device you can plug in or something similar that would tell you if another receptacle was installed between the first receptacle and the panel. People have asked me that several times, and I keep forgetting to find out. I don't know of anything personally, but hopefully someone with more hands on electrical experience will.

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Originally Posted by Jim Robinson

You can protect receptacles down stream by using a GFCI device at the first receptacle. Is there a quick way to determine which is the first receptacle? I've done it by trial and error, but was wondering if there is a device you can plug in or something similar that would tell you if another receptacle was installed between the first receptacle and the panel. People have asked me that several times, and I keep forgetting to find out. I don't know of anything personally, but hopefully someone with more hands on electrical experience will.

Hi Jim,

First turn off the breaker for the circuit that you want to check.
Next, plug lights into each of the receptacle outlets on that circuit.
Turn on the circuit breaker
Run back into the room really fast (refer to Einstein's theory of relativity, specifically speed of light).
See which lights turn on first.

Sorry, I had too much time on my hands this afternoon. I don't think there is any way except guesswork (the one closest to the panel is my first guess) and trial & error.

No there is not, without taking the circuit apart to see if part is still alive after tripping the GFI.

Not always does the first receptacle need the GFI protection. For example a receptacle could be on a kitchen wall that does not serve the countertop, but the circuit eventually does make it to the countertop.

Originally Posted by Jim Robinson

You can protect receptacles down stream by using a GFCI device at the first receptacle. Is there a quick way to determine which is the first receptacle? I've done it by trial and error, but was wondering if there is a device you can plug in or something similar that would tell you if another receptacle was installed between the first receptacle and the panel. People have asked me that several times, and I keep forgetting to find out. I don't know of anything personally, but hopefully someone with more hands on electrical experience will.

Not being wise in the slightest but I am just curious. Why do they want to know and why would it matter. As long as the receptacles down stream are protected.

I guess if it is idle curiosity but as Jim port already said and explained. No real way to figure that out other than testing ever receptacle of any kind in the home to see if there is not power other than the GFCI protected receptacles. I do have people ask me curious similar questions at times

Originally Posted by Jim Robinson

You can protect receptacles down stream by using a GFCI device at the first receptacle. Is there a quick way to determine which is the first receptacle? I've done it by trial and error, but was wondering if there is a device you can plug in or something similar that would tell you if another receptacle was installed between the first receptacle and the panel. People have asked me that several times, and I keep forgetting to find out. I don't know of anything personally, but hopefully someone with more hands on electrical experience will.

You can measure the resistance of the wire with a DMM to see which receptacle is first in the string. Turn the breaker off. Make sure no devices are plugged in. Measure the resistance between the neutral and ground at each receptacle. They are bonded at the panel, so you are measuring the resistance of the loop.

Originally Posted by Ted Menelly

Not being wise in the slightest but I am just curious. Why do they want to know and why would it matter. As long as the receptacles down stream are protected.

It would save a lot of time in determining which was first, so that you could protect the down stream receptacles. I'll try measuring the resistance some day and see if that works. Unfortunately, for most of the places it's needed there isn't going to be a ground wire.

Measuring voltage drop possibly? I know there are some other factors that can affect it, but that would be one thing that would change slightly as you got farther from the panel.

Originally Posted by Ted Menelly

Not being wise in the slightest but I am just curious. Why do they want to know and why would it matter. As long as the receptacles down stream are protected.

Because the kitchen does not have any GFCI. The home inspector retells the client there is a lack of GFCI in the kitchen. The helpful home inspector explains that by installing a GFCI at the first receptacle in the circuit, everything downstream is protected. The client then asks which receptacle if the first one in the circuit so they can add a GFCI.

I tell them to pull the receptacle and the one with only one set of wires coming in is the end of the circuit. The receptacle on the other side of the kitchen is likely the first one.

Originally Posted by Bruce Ramsey

Because the kitchen does not have any GFCI. The home inspector retells the client there is a lack of GFCI in the kitchen. The helpful home inspector explains that by installing a GFCI at the first receptacle in the circuit, everything downstream is protected. The client then asks which receptacle if the first one in the circuit so they can add a GFCI.

I tell them to pull the receptacle and the one with only one set of wires coming in is the end of the circuit. The receptacle on the other side of the kitchen is likely the first one.

The only problem with that is if there are no GFCIs then it is an older home and both ends may be feeding another receptacle.

After that the only choice is to pull the receptacle out at each end, pull he hot wire off of one and check the receptacle at the other end. If it is dead we have a winner. The only problem with that is I look real closely at the prospective buyers to see if I can figure out if they are going to die doing this themselves and then explain that is the way the 'electrician will likely do it and do not suggest that they do it.

Originally Posted by Jim Robinson

Measuring voltage drop possibly?

That would only work if all the connections were good, but get one bad connection to a receptacle and you are back to guessing.

I've had decent success on using my SureTest for this using voltage drop, but you have to discount the high voltage drop ones and just use the reading which notch up as you go around the room - which means you are basically 'guessing' as to what the voltage drop is indicating.

Originally Posted by Jerry Peck

That would only work if all the connections were good, but get one bad connection to a receptacle and you are back to guessing.

I've had decent success on using my SureTest for this using voltage drop, but you have to discount the high voltage drop ones and just use the reading which notch up as you go around the room - which means you are basically 'guessing' as to what the voltage drop is indicating.

When i originally read the op i read it wrong as in, could there be one before the receptacles in question. As in somewhere else in the home.

My second post reflected to other possibilities

I also stated that it is always wise to add that an electrician can/should do it so when they fry themselves based on what i mentioned on how to do it, i could sleep at night knowing that i warned them away from it.

Originally Posted by Ted Menelly

When i originally read the op i read it wron as in, could there be one before the receptscles in questioni. As in sonewhere else in the home.

My second post reflected to other possibilities

I also stated that it us always wise to add that an electricuan can/should do it si when they fry themselves based on what i mentioned on how to do it i could sleep that i warned them away from it.

Ted,

Are you okay? Really, are you okay?

That post was like someone with a stroke trying to talk or type ...

Originally Posted by Jerry Peck

Ted,

Are you okay? Really, are you okay?

That post was like someone with a stroke trying to talk or type ...

Just fine Jerry

I was texting a client and waiting for a response. The thread popped up on the phone so I killed time while waiting for the client to return his answer for tomorrow.

I try not to comment on wording and spelling from you or others because I am famous for screwing it up myself. If you read it again I corrected things when I was able to get back to the computer and report. I have the biggest screen there is for a smart phone and my fingers are still to big and the screen too sensitive.

Are you OK? Are any of us OK? I am OK. Thanks for asking.

Just way to busy this week and cannot get away from the phone or the computer. Answering calls. Texting. Reporting. Scheduling and then rescheduling and then rescheduling. 4 jobs this week have been rescheduled at the very least 3 to 4 times each so far.

Originally Posted by John Kogel

You can measure the resistance of the wire with a DMM to see which receptacle is first in the string. Turn the breaker off. Make sure no devices are plugged in. Measure the resistance between the neutral and ground at each receptacle. They are bonded at the panel, so you are measuring the resistance of the loop.

John, they are ignoring you because common sense logic would just kill the thread .

Originally Posted by Vern Heiler

John, they are ignoring you because common sense logic would just kill the thread. .

Nah. He wants a method that would work for ungrounded circuits. A resistance measurement would entail pulling the hot wire and jumping it to the neutral in the panel. Measuring voltage drop is quicker in that case.

I saw a GFCI receptacle mounted in the ceiling above the panel in the basement one time. The 'electrician' used that to feed the bathroom circuits. Wierd, because he could have just installed it in the first bathroom outlet.

As a home inspector you should not be doing this yourself, except possibly on your own stuff, and definitely not be showing anyone else how. It is easy enough to verify if a circuit with the first receptacle needing to be a GFCI is actually wired that way without disassembling anything

But, if it was me and I was looking for the first one, I'd turn off the breaker and remove the wire from it. After first measuring between the line wire and neutral to make sure there is a very high resistance (nothing plugged in), tie the wire to the neutral buss . And, if a multi-wire circuit you need to turn off the other leg - just because.

At that point you can read the resistance of the loop through each receptacle. Lowest should be the first receptacle. Not 100% foolproof as adjacent wires can induce voltage and screw up readings.

You can also apply a DC voltage to the hot and neutral ( after you've unhooked things as above) and hook some identical low Ohm high wattage resisters (mine are hooked to cord caps) across each receptacle, then measure the voltage at each receptacle. Highest voltage is at the nearest receptacle to the DC supply, lowest at the furthest. You can find bad connections exist like this too.

John's method works most times on a circuit with equipment grounding conductors, but I find that if you have some, not all, metal boxes grounded with a clip instead of a screw, and someone has elected to use a self grounding receptacle in one of those boxes that the differences in resistance can foul things up.

The safety stuff-use a tester to verify the receptacles you are testing are off on both top and bottom (or both ends) and mark these with something like blue tape. It can be a not so pretty thing if you plug a VOM set to resistance into a live receptacle. They should be fused, but...........

Older homes often not wired like todays new construction.

Especially homes that weren't intiitally electrified, and older homes which have had changes.

Point being that the circuit may not be a simple path from source to receptacle A, then to B, then to C and so forth, for example: power from the panel to the ceiling center of the room, then parallel drops in stud cavities to receptacles on the east wall, the north wall, the west wall, etc, thus a gfci receptacle on the east wall may have no other receptacles on its line side, or its load side, or perhaps has a few load side, but doesn't effect the receptacles on the north or south wall. IOW, you can have 2, 3, 8 receptacles that are all tied for "first" in parallel.

As indicated by another MWBCs also were common, it is common to find them in older homes. It is more common to have found an unqualified party has altered the system at some point

These are the very reasons "back in the day" when replacing 2-wire system receptacles was not permitted to protect "downstream" receptacles. That restriction was later dropped, as the NEC is not a "how to" book, nor is it a design guide.

A qualified person can trace a circuit path. It requires hands-on, on-site examination, testing, and follow-through. Yes it may require every junction be accessed, opened, examined, and tested. That's why junctions are required to be accessible.

With the hoards of "how to" electrical books having been recalled of late, why would an HI "go there" regarding specific instructions. Stick with the concept that the wiring system has safety concerns, or defects, and needs correction, upgrading, to include X, Y and/or Z for safety.

Refer the DESIGN for corrections for the future HO to a qualified, licensed party who has examined on site. Sometimes a deadfront elsewhere (such as near the panel) is an option.

A bit off topic, but I feel that wiring GFCI receptacles in series is ridiculous in the first place. I recently inspected a 2-year-old home with all four bathrooms wired this way. There were 5 occupants, including three minors, living there. The one GFCI did not trip when tested. That is common since they are only guaranteed to do one thing - FAIL one day. This is why they must be tested.

And so there was no GFCI protection for ANY of the occupants in ANY of the bathrooms, because the occupants didn't test the receptacle EVERY MONTH. How many people really do that anyway????? 10%, 5%, 1%, or less, maybe.

If each bathroom was required to have its own GFCI protection, it is likely that the other 3 in this newer home would still have been protected. Or at least likely that they would not have ALL failed within 2 years. How many homes in North America are currently, and dangerously, wired like this? One is too many, and only for a cost if about $16.00 per bathroom.

Of course, even if there were 4 GFCIs, it is imperative that they all be tested. I use this example to emphasize to every Client the importance of monthly testing, and especially when wired in series.

Originally Posted by Ted Menelly

Just fine Jerry

I was texting a client and waiting for a response. The thread popped up on the phone so I killed time while waiting for the client to return his answer for tomorrow.

I try not to comment on wording and spelling from you or others because I am famous for screwing it up myself.

I wasn't commenting on your wording or spelling, just that when I read it the vision of someone sitting there trying to speak (type in this case) when they knew what they wanted to say but the words just would not come out as they wanted the words to come out - I've known several people who have had strokes and sometimes that is what happens after (or during) a stroke ... the mind is there, it knows what it is trying to say, but there is a disconnect between the mind and the voice (or fingers in this case).

Glad you are okay.

Now, me? Okay? That is one of the few things I have not been accused of or called.

In fact, just this morning I went to my doctor to find out my sleep study results to see if I have sleep apnea (a couple of weeks ago I had a sleep study done, the guy said the curves were real interesting, I said "I like flat lines, flat lines are boring, I like boring."), anyway, turns I when I sleep that I stop breathing about every two minutes for up to about half a minute each time.

That's not good.