GFCI outlet on the load side of a GFCI outlet

A 1955 house with ungrounded outlets except for new branches added since. I'm adding TR GFCI outlets to the original first outlet in each branch (if I can find them - if not I'll replace those that do not turn off on a test). Two branches go from the old fuse panel (since replaced with THHN lines coming from a new panel) to 2-3 bedrooms, to lights, to halls, and end up at a bathroom which already has a GFCI outlet installed. Is there harm in simply leaving the bathroom GFCI's installed? Wouldn't they trip first if something happened at them, or if they both tripped is that a problem (besides having to reset the other one first)?

 

It's not a problem having two GFCI receptacles on the same circuit, but if one trips all the receptacles, including another GFCI receptacle, down the circuit will be affected.

 

Nope, don't do it. Put the bathroom receptacles on the LINE side of the GFCI preceding it. That said, current code says the bathroom has to have its own circuit but that's another can of worms.

 

Not wanting to start a new thread. So, this first branch goes all over the place (outlets in 5 rooms, a bathroom and its light and fan, lights in one room and 3 hall lights). I just used one of the hall lights and the GFCI goes off immediately. The lights worked before and they are track lighting like 2 others used in the house. Is the only explanation that the neutral used on this circuit not the one that goes with the hot? It is hall lights with 3 switches. How do I troubleshoot this?

 

BillA: It is just a better way to remove any GFCI receptacles downstream of a GFCI (when wired to "load") no matter their location. Once you install a GFCI upstream of the bathroom a regular receptacle is acceptable in the bathroom. The GFCI upstream will protect that area.

Although having a GFCI downstream of a GFCI is not a major factor it is a waste of money for the downstream GFCI and you may end up with tripping of either of the GFCIs when really there is no issue involved.

 

A GFI downstream can cause the first one to trip.
Then if you don't realize the first one tripped... the second one won't reset.

A little off the main topic......
I work in a high end condo development. Many groups of 8-10 units.
When they were built it was ok by code to use one GFI device to protect a circuit.
The circuit went to one bathroom with a GFI receptacle - then to a second bathroom - then to a powder room - then to one or two outside receptacles - then to several garage receptacles - then to the basement. My ace was that the doorbell was on a basement receptacle. I'd ask them if the doorbell worked. If it didn't... I knew the GFI was tripped.

Most of my customers did not like that situation. So I go in and change each receptacle to a GFI receptacle. It's easy to do. You connect the power in and power out cables to the LINE terminals and don't use the LOAD terminals. Each receptacle is its own protected location. One location cannot trip another location.

 

So you installed a individual GFCI receptacle at each of the 10 to 12 regular receptacle locations which had previously been protected by the one lone GFCI. I guess that's a sure-fire way to prevent an upstream GFCI from killing downstream receptacles while having a GFCI receptacle at each of those multiple locations. Each GFCI would trip if its internal inductance coil detected a ground fault at that particular location and not be a slave to a GFCI upstream. You must have been buying the GFCI receptacles by the cases! ​​​​​​​

 

I have seen some electrician (not sure if they are licensed) installing GFCI on every single outlet on kitchen counter claiming that is the new code. Probably mistook "GFCI protected" as needing GFCI receptacles. Problem is, this guy also wired down stream GFCIs to load terminal of each other. If the last one trips, GFCIs upstream trips as well.

I also have seen someone replaced all outlets in bathrooms to GFCIs. The problem is, they were already GFCI protected by GFCI receptacle in the basement. GFCIs were also wired to load sides. I tested the last GFCI, every GFCI upstream tripped.


Just do not put another GFCI on load side of another.

 

Lambition:
"I have seen some electrician (not sure if they are licensed) installing GFCI on every single outlet on kitchen counter claiming that is the new code. Probably mistook "GFCI protected" as needing GFCI receptacles. Problem is, this guy also wired down stream GFCIs to load terminal of each other. If the last one trips, GFCIs upstream trips as well."

New code saying every receptacle in the kitchen must have a physical GFCI in place - I don't think so. I have not be up to code in some time since retired but logic tells me that it would make no sense to do this.

Wiring GFCI on "Load" to downstream GFCIs also makes no sense logically.

Again, I have been retired for awhile but I don't think code would dictate this.

"Just do not put another GFCI on load side of another." - I agree.

 

I prefer for all receptacles on the kitchen counter to be on one GFCI, and each bathroom's receptacles to be on one GFCI.

I prefer that all garage receptacles to be individual GFCI receptacles, and prefer that all outdoor receptacles and HVAC service receptacles to be individual GFCI receptacles.

I have no problem with some receptacles in the garage and receptacles nearby the garage (e.g. garage apron or driveway) being protected by GFCI circuit breakers if the circuit breakers are in a panel located nearby in the garage.

I like 20 amp circuit GFCI receptacles for garage, HVAC service and outdoor locations.

The emphasis is on protection but also convenience to reset a GFCI if one trips.

 

BillA-In-CT:
It is very possible. Remember, the current on any circuit will want to return to its original location which is your panel (actually out further than that to the pole). Keep it simple. Think of the plumbing in your home. The water comes in your home and then back out thru the drains to the sewer.

First of all GFCI or not you never want to share a neutral from one circuit to another. You can actually overload a neutral this way.

GFCIs are sensitive: A GFCI, whether it is a breaker or receptacle will measure the current going out on the hot and returning on the neutral if there is an imbalance of 4-6maps or more the GFCI will trip because there is a ground fault. So if a circuit shares a neutral with another circuit the return amps will not be balanced and will trip the GFCI. There is more detail than this but that will give you the idea of how the GFCI senses an imbalance on the neutral.

Again, a neutral on one circuit should never be shared with another circuit. The only time (in simple DIY terms) a neutral may be shared on two different circuits is if a proper MWBC is set up properly. You can Google what a MWBC (m.ULTI w.IRE b.RANCH c.IRCUIT) is which will give you a better understanding.

 

Current travels in completed loops. Current wants to get to a load source to complete its full loop or 'circuit'. Current does not want to get to ground. For a hot leg the source is neutral. Grounding is designed to return errant hot to source, and it does that by the one and only (sole) neutral-ground bond, which is in the main service panel.

Typical 20 Amp Garage GFCI Receptacle

 

Don't forget 20A receptacles must be on 20A circuit. Cannot install 20A receptacle on 15A circuit.
I have seen this many times as well.

 

I opened a 4-gang box that (no surprise) has 4 branches inside! One is a 3-way on the end, so no neutral there. And then there are 4 white wires all tied together! Assuming they are neutral I think this is the problem. I need a chunk of time because the wires are all so short that I have to remove the 3 switches. There are no wire nuts - wires are twisted together and taped. And a common thing I see here and elsewhere is a long wire stripped half way and chained from one outlet or switch to the next. I also found a taped splice in a wall so I know things are poorly wired.

I hope I can separate the neutrals and figure out what goes where. I'm expecting that this may have been wired to simply use a neutral in the box and I may have to undo the load side of the GFCI and install individual outlets.

One more thing. I bought a cheap (mistake?) 10-pack of 3GRACE GFCI outlets. When I install an outlet tester with the GFCI test button it doesn't open the connection at the outlet or ones on the load side. Does this mean it is bad or just not as sensitive as other outlets this test does work on?

Thanks for all the replies and added information. I read this forum all the time. It's very informative.

 

I had never heard of 3GRACE before!

That's NOT a good thing!

Pressing the GFCI test button simulates a ground fault by putting a resistor between the hot and the ground which causes a current to flow that exceeds the 4 to 6 mA (0.005 to 0.006 amps) allowed before tripping and opening the circuit.

Current to Ground value in the range of 4 milliamps 6 milliamps references UL 943 that covers the Standard for Safety for Ground Fault Circuit Interrupters for personal protection in accordance with the National Electrical Code.

I have no clue why the 3GRACE GFCI outlets are not tripping because 3GRACE states the following:

3GRACE GFCI Outlet - The 15 Amp 125 Volt 60 HZ GFCI Duplex Receptacle meets UL 943 class A and UL 498 receptacle standards.

 

BillA In CT:
If you are using a plug-in tester to test the GFCI outlet/receptacles (this will also happen with a GFCI breaker) the plug-in GFCI tester will not trip any GFCI if the GFCI is not grounded but the GFCI receptacle or GFCI breaker will still function correctly for safety. To test a GFCI receptacle or breaker if the circuit is not grounded use the "test" button on the GFCI receptacle or breaker to test. This is an acceptable method of testing. Electrical inspectors also know this (well most do at least-I had to educate a few HUD inspectors on this).

 

Does it work with test button built into GFCI? If it does, it is working properly.

Built in test button shorts hot to neutral through resistor without running through current sensing coil. However outlet tester with GFCI test function shorts hot to ground through resistor because you cannot bypass sensing coil to neutral externally. Since you don't have ground, this test will not work because there will be no current at all.

 

BillA_in_CT - Your 1955 house with ungrounded wiring and GFCI installed should not trip using a plug-in tester - because there is no ground. Be glad it does not trip using the plug-in tester because if the GFCI does trip using plug-in tester's trip feature then it indicates a 'bootleg' ground which defeats the purpose of having a GFCI personal protection device.

 

I had no idea these plug in testers didn't work without a ground. If the packaging mentioned this I clearly missed it. It makes perfect sense. The tester would have to divert current somewhere else to cause an imbalance. There is no place else. You bring up a good point too - if the tester works then I have a bootleg neutral[1]. I have found one already a few years ago. I also found several cases where they added grounded outlets and they added a green ground wire from the green screw to the box. LOL there is no box ground - the box is floating!

I canceled my return of the 3GRACE devices because I'll probably need them when I can't find the first outlet on a circuit. It was a great price for 10. On the second branch I was wrong and had 2 outlets in the middle of the room go out on a test! I may end up doing every outlet, especially because of the neutrals being tied together problem.

[1] Edit: But the bootleg would have to be on the GFCI that I put in which wouldn't happen. It wouldn't find a bootleg downstream.

 

Actually, it won't trip even in that case. Current returns back to neutral. As far as GFCI can see, everything is good.

Sometimes it is grounded even when you don't see ground wire. Some old installations actually had cable with ground, but had ground wire wrapped around in the back and put under romex connector or twisted onto holes in junction box. Not very noticeable unless you look real carefully.

My house was built in 1954, and that is exactly how they were wired.
I was lucky they used cable with ground, so I don't have to rewire whole house. Ground wires are much thinner (probably 18 AWG?), but good enough in most cases.

 

​​​​​​​I prefer two GFCI receptacles on the kitchen counter for the two small appliance branch circuits.

 

BillA In CT:
"I may end up doing every outlet, especially because of the neutrals being tied together problem."

If neutrals from one circuit go to another circuit this must be addressed. Read my post #11. Neutrals can not be shared from one circuit to another. GFCIs will not ease the issue with shared neutrals.

 

Thanks AFJES. So I separated all 5 white wires. An inch of one was longer and was wrapped around the 5 of which 4 were soldered together. So, with none touching, the lights work the same (the GFCI trips and the lights flash briefly). I unhooked the fixture and it doesn't pop. I wired in a dangling outlet and an incandescent lamp plugged in and it trips. It's not the fixture. It's 2 3-way and a 4-way circuit. I'll check the other 3-way. They seemed to like switch loops or 3-ways that have the neutral at the load. This is tedious for sure,

 

I give up. One 3-way is common to light and travelers. The 4-way in the middle can't cause a problem (I hope). The other 3-way has power and travelers. So the neutral in the attic to this fixture (which is 8 feet from another fixture on this branch that works!) must be for a different branch. Running a new wire from the other fixture to the bad one only for the neutral would probably solve it.I'll look at it when I have nothing else to do.

 

BillA_in_CT - Have to solved the original GFCI outlet issue and now you're moving toward dealing with separating neutrals and figuring out how to get fixtures to work with all the 3-ways and 4-ways?


You said that you separated the 5 neutrals tied together, some of which were soldered. That's a good beginning because neutrals for one circuit cannot be used for another circuit..

Do you know how many different good circuits it would take to clean up your fixture/switch dilemma?

You said you've identified one working fixture. Is this maybe an oddball correctly-wired circuit and fixture from beginning to end? Or, are you still questioning how the fixture is able to work with all the 3-ways and 4-ways abound and the now separated bevy of shared neutrals in the mix?

During your research and findings in the attic you were able to identify a neutral that you said must be for a different branch. What makes you think it's a different branch? You said you believe running a new wire from the fixture that woks to the fixture that doesn't work (so you can use the new wire's neutral) will probably solve it (i.e. get that non-fixture working too). I presume you'll wire the non-working fixture to be On at the same time as the now working fixture once you run and connect the new wire.

How many more of these problematic circuits are there to track down and sort out?

I'm curious, is there even a slight possibility of being able to rewire the house?