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A family member has an old house probably built in the '50s. The electrical system is not grounded. However, the panel has breakers not fuses. First question: Would the breakers likely be original or added later?
At some point in time, some of the outlets were replaced with new 3 prong outlets. They are marked "no ground". Also, the kitchen and bath have new gfci outlets.
Question 2: Would gfci circuit breakers in the panel be a good solution for better protection? I understand that regular circuit breakers on a non-grounded system will sometimes trip and sometimes not when a problem occurs.
Question 3: What do gfci breakers do that non-gfci breakers don't?
Question 4: If the answer to #2 is yes, does the panel need to be grounded for them to work? I'm unsure if the panel is presently grounded or not. I'm assuming it is not.
Question 5: If gfci breakers are installed in the panel is the system as well protected as it would be with a ground wire?
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03-07-2024, 06:53 PM
(This post was last modified: 03-07-2024, 07:14 PM by Snipe Hunter.)
Take some pictures for me please. I want to see the breakers and the label on the panel door. I need a brand name. Most GFCI breakers are made for modern panels. If it was a real common panel and doesn't have any recalls, you might be able to find GFCI breakers. I'd also like to know about your wiring. Cloth sheathed Napex with no ground? Armored cable with no ground?
Look up "Bootlegging". Some jurisdictions allow GFCI receptacles on ungrounded circuits. I think they connect the white neutral wire to the ground lug on the GFCI receptacle and to the neutral lug on the receptacle. This is supposed to offer some level of protection. Not all jurisdictions allow this. I'll admit, I don't know how this works and it was a no-no when I was learning about this stuff but I do know it is allowed in some places.
#2 GFCI breakers won't give you a ground. They need a hot, neutral and a ground to function properly. They won't trip without a ground.
#3 GFCI breakers trip when it detects a ground fault. It can't detect a ground fault without a ground. Non GFCI breakers trip when the circuit is overloaded.
#4 The answer to #2 is no. My guess is that the panel is grounded. You should see a copper or aluminum solid wire (maybe stranded) bonded to the panel with a screw. That wire is connected (bonded) to a known ground. It may be a ground rod outside (look outside the wall), it can be inside, look below the (panel) for a ground rod. It may also be bonded to a water pipe.
#5 The system will provide the same protection as the original non grounded breakers.
I have seen old panels retrofitted with ground and neutral blocks. Then either modern (2 conductor -1 gnd) NM wire is re strung through the house. I've also seen individual grounds wires run to each circuit/receptacle. I've also seen the armored cable jacket, bonded at both ends giving you a ground, check your local code office. If you have armored cable, both ends may already be bonded. You'll have to install grounded receptacles and connect (bond) a ground wire from the receptacle to the metal box. Usually, there is a threaded hole in the box for a ground screw. If you have 2 conductor, clothed sheathed (Napex), you will either have to run a ground wire or run new Romex (NM Cable).
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Pretty sure GFCI with no ground wire will still trip if overloaded. I recall reading it will proteta person but probably not equipment.
Is there any way to pull SOME new wire? Even if just for the kitchen, for example...
Putting a jumper from ground to neutral... I think any electrician will say HECK NO! Having said that, an electrical engineer suggested I do that in our first house. They "test" normal with a meter. The ground and neutral are tied together in the panel anyhow...so I wouldn't recommend that, but somebody else may, and I've done done it.
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(03-07-2024, 08:37 PM)JosephP Wrote: Pretty sure GFCI with no ground wire will still trip if overloaded. I recall reading it will proteta person but probably not equipment.
Is there any way to pull SOME new wire? Even if just for the kitchen, for example...
Putting a jumper from ground to neutral... I think any electrician will say HECK NO! Having said that, an electrical engineer suggested I do that in our first house. They "test" normal with a meter. The ground and neutral are tied together in the panel anyhow...so I wouldn't recommend that, but somebody else may, and I've done done it.
Yea, some will and some wont. Even if it's accepted by the JHA.
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(03-07-2024, 08:37 PM)JosephP Wrote: Pretty sure GFCI with no ground wire will still trip if overloaded. I recall reading it will proteta person but probably not equipment.
Is there any way to pull SOME new wire? Even if just for the kitchen, for example...
Putting a jumper from ground to neutral... I think any electrician will say HECK NO! Having said that, an electrical engineer suggested I do that in our first house. They "test" normal with a meter. The ground and neutral are tied together in the panel anyhow...so I wouldn't recommend that, but somebody else may, and I've done done it.
A GFCI will trip on a ground fault without a ground, The gfci compares the current in the hot to the neutral, they have to be equal for it not to trip, too little or too much current on the neutral wire will trip it. Thus the sticker to mark no ground. A gfci receptacle is not a overload device like a breaker so it is not made to trip on a overload. Remember if you bootleg a ground and that neutral is regrounded the gfci will trip because the neutral current now has a parallel path so the current will no longer be equal to the hot leg.
The panel from the 50's is probably grounded as that has been code for many years. If it is a Federal Pacific panel it will not have a gfci breaker available. Roly
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(03-08-2024, 07:02 AM)Roly Wrote: A GFCI will trip on a ground fault without a ground, The gfci compares the current in the hot to the neutral, they have to be equal for it not to trip, too little or too much current on the neutral wire will trip it. Thus the sticker to mark no ground. A gfci receptacle is not a overload device like a breaker so it is not made to trip on a overload. Remember if you bootleg a ground and that neutral is regrounded the gfci will trip because the neutral current now has a parallel path so the current will no longer be equal to the hot leg.
The panel from the 50's is probably grounded as that has been code for many years. If it is a Federal Pacific panel it will not have a gfci breaker available. Roly
You'd be surprised how many of these I see in high rise condos in DC. Most of them have ground wires running to receptacles. There are electricians still making a good living just replacing FP panels. Since almost all of them are over a countertop in the kitchen, they have to move it to another room. I recommend 2 brothers who do nothing but that. One is a licensed electrician and the other is a drywall/painter. They're getting $3k for the electric and a few hundred to repair drywall. They replace them with similar sized 60 or 100 amp panels, larger if they have an electric dryer. They gut the old enclosure and use it as a junction box and screw the cover closed. Most of these places are on a chiller/boiler loop with radiators so no AC.
Once they get in a building, they'll get a ton of work there.
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(03-08-2024, 07:02 AM)Roly Wrote: A GFCI will trip on a ground fault without a ground, The gfci compares the current in the hot to the neutral, they have to be equal for it not to trip, too little or too much current on the neutral wire will trip it. Thus the sticker to mark no ground. A gfci receptacle is not a overload device like a breaker so it is not made to trip on a overload. Remember if you bootleg a ground and that neutral is regrounded the gfci will trip because the neutral current now has a parallel path so the current will no longer be equal to the hot leg.
The panel from the 50's is probably grounded as that has been code for many years. If it is a Federal Pacific panel it will not have a gfci breaker available. Roly
To clarify.. for my own knowledge. Will it trip if not bootlegged? I have to check these and I don't think one has ever tripped for me if my tester was showing an open ground.
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Roly is correct. The GFCI (Ground Fault Circuit Interrupter) receptacle compares current flowing on the hot and neutral. If everything is working correctly the difference will be zero. If there's an imbalance of 3 - 5 mA (milliamps), the GFCI assumes that some current is flowing on the equipment grounding conductor (EGC) and trips. The NEC Article 406.4(D)(2) allows replacing a non-grounding (2 prong) receptacle with a GFCI receptacle which works just fine without a ground wire.
Non-grounding receptacles can be replaced with grounding-type where they are fed from a GFCI. These must be marked "GFCI Protected" and "No Equipment Ground". A typical GFCI receptacle tester won't work on these, because the tester shunts a small current onto the EGC to trip the GFCI. So the tester won't work, but they are NEC compliant.
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(03-09-2024, 08:19 AM)BAdams Wrote: Roly is correct. The GFCI (Ground Fault Circuit Interrupter) receptacle compares current flowing on the hot and neutral. If everything is working correctly the difference will be zero. If there's an imbalance of 3 - 5 mA (milliamps), the GFCI assumes that some current is flowing on the equipment grounding conductor (EGC) and trips. The NEC Article 406.4(D)(2) allows replacing a non-grounding (2 prong) receptacle with a GFCI receptacle which works just fine without a ground wire.
Non-grounding receptacles can be replaced with grounding-type where they are fed from a GFCI. These must be marked "GFCI Protected" and "No Equipment Ground". A typical GFCI receptacle tester won't work on these, because the tester shunts a small current onto the EGC to trip the GFCI. So the tester won't work, but they are NEC compliant.
Thank you. Great explanation.
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Thanks for all the replies. I'm afraid I don't understand all of what you said, but I now know what a bootleg is.
I can't easily give you any more information as the house is about 200 miles away and the information is from what my SIL tells me and he knows even less than I do about electricity. As I said, the electrical system is ungrounded and he is not likely to do anything to change that except what may be required to make it functional and legal. I'm assuming that the breakers in the main panel are not gfci. So, they provide basic overload protection only. What I would like to know is what additional protection, if any, gfci breakers or outlets would provide. One comment above says that they will trip, if needed, on a ungrounded system. This confirms what I've read elsewhere. He already has one of the gfci outlets in the kitchen and in the bathroom which, I understand, provides better shock protection. Would he be well advised to install more? For instance, would they offer better protection for his electronic devices?
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