Will GFCI work with items without equipment ground

[mikestock]

I know it's probably a dumb question but my wife's hair dryer is old and has no equipment ground. Wanted to be sure she is still protected if it should be dropped into water or otherwise shorted.

[Optimistic_Para]

Bobbo wrote:
I replaced the $12 GFCI and had no more problems.

And this is the other reason why GFCI does not obviate the need for a third grounding wire. They fail way too often, and according to that bastard Murphy, they're going to fail when you need them the most!

[Optimistic_Para]

Sam Spade wrote:
......nor would I ever put one on a sump pump, even though the electrical code requires it.
That second one requires you to be VERY careful when you wade into the water if the sump pump ever does fail.

They make 12 volt sump pumps, primarily so they can keep running off the battery if a storm knocks the power out, but I imagine they would also protect you if you were wading in the water.

[Bobbo]

I had a freezer in the garage on a GFCI outlet. Worked fine for years. Finally, it started tripping the GFCI. I bought the largest most expensive freezer they made to replace the freezer that kept tripping the GFCI. The new freezer tripped the GFCI. I replaced the $12 GFCI and had no more problems. DW has not let me live that down yet, and it has been 20 years.

[Sam_Spade]

road-runner wrote:
I have a fridge and freezer in the house, plus the RV fridge, all on GFCI circuits with zero trips in 10+ years.

You are lucky.

Every house I have owned since GFI came into common use....about 5 of them.....has been prone to tripping the GFI outlets during thunderstorms (think power surges).

I would never put one on a seldom used freezer......nor would I ever put one on a sump pump, even though the electrical code requires it.
That second one requires you to be VERY careful when you wade into the water if the sump pump ever does fail.

[Sam_Spade]

Harvey51 wrote:
Would it be fair to suggest that the safety ground system is a waste of copper when all circuits are GFCI protected?

NO.

For the GFI to work, that unintended part of the device that is now "hot" needs to shed it's power to ground by some means other than the neutral wire.

If there is no ground "wire" present, that path is likely to be through something else dangerous......like a human hand.

[wnjj]

road-runner wrote:

Harvard wrote:

Just imagine if your fridge or freezer was powered by a GFCI.....

Not sure what the message is, but I also don't have to imagine. I have a fridge and freezer in the house, plus the RV fridge, all on GFCI circuits with zero trips in 10+ years. RV has been powered by 3 different generator make/models over that time.

I added a second small freezer to our garage and the one GFCI-free receptacle was already taken so I plugged into a GFCI one. Twice I found the freezer off and getting warm. That receptacle got rewired for now. 😉

So yeah, there’s a good reason fridges and freezers don’t require them.

[road-runner]

Harvard wrote:

Just imagine if your fridge or freezer was powered by a GFCI.....

Not sure what the message is, but I also don't have to imagine. I have a fridge and freezer in the house, plus the RV fridge, all on GFCI circuits with zero trips in 10+ years. RV has been powered by 3 different generator make/models over that time.

[DrewE]

Harvard wrote:

Just imagine if your fridge or freezer was powered by a GFCI.....

We have a condo with a den. The den is used as a pantry c/w an upright freezer.
Being a den it is powered on the same "anti arc" breaker as our bedrooms.
Oh well, you know the rest of the story...

From what I've read, AFCI (arc fault circuit interrupters) are far more prone to nuisance tripping than GFCIs. Part of the reason is that some appliances, particularly ones with largish universal motors like power tools and vacuums, naturally have some arcing internally in operation that is not an actual fault or danger. Another part of the reason is that they detect arcs by "listening" for certain noise frequencies on the electrical line (or combinations of noise frequencies), and if you're unlucky some switching power supply or motor controller may generate a little noise that looks enough like an arc to it to trip it.

I'm very glad my house predates the AFCI requirements. I'm less glad it predates the GFCI requirements and have been adding in GFCIs where appropriate as I have reason to work on the electric system.

[Harvard]

pianotuna wrote:
Sam,

My Magnum hybrid inverter/charger trips on SOME but not all GFCI outlets. When I remove the inverter from the circuit path, the RV does not trip any of the GFCI outlets.

This behavior is why I'm getting bald. * grin *.

Another anomaly is that occasionally when I run the Yamaha generator, the one and only gfci circuit in the RV may trip. Again--not always. And it does reset.

Just imagine if your fridge or freezer was powered by a GFCI.....

We have a condo with a den. The den is used as a pantry c/w an upright freezer.
Being a den it is powered on the same "anti arc" breaker as our bedrooms.
Oh well, you know the rest of the story...

[pianotuna]

Sam,

My Magnum hybrid inverter/charger trips on SOME but not all GFCI outlets. When I remove the inverter from the circuit path, the RV does not trip any of the GFCI outlets.

This behavior is why I'm getting bald. * grin *.

Another anomaly is that occasionally when I run the Yamaha generator, the one and only gfci circuit in the RV may trip. Again--not always. And it does reset.

[Gdetrailer]

Harvey51 wrote:
Would it be fair to suggest that the safety ground system is a waste of copper when all circuits are GFCI protected? If the cost of copper and electrician labour keeps rising it may become cheaper to go with GFCI breakers instead of ground wiring.

No.

Think of it as a "belt AND suspenders" type of thing.

Some electric items simply cannot be "double insulated" and therefore a "safety ground" is an essential must have.

Some examples of items which can not be "double insulated" are large appliances like fridge, microwaves, stoves, washers, dishwashers and so on.. Some appliances which have critical role like a fridge are not required to be on a GFCI even if in a basement or garage (don't want a fridge to shut off from a false trip).

Safety ground also stops the "skin effect" some items can exhibit which due to natural capacitance often will allow a device to have some slight potential above ground.

This typically can happen to RVs using 30A 120V service with a extension cord that is missing the ground or has a broken ground wire.. Often called a floating ground on the RV chassis which will show 5, 10 or more volts and "bite" you when you attempt to touch anything metal on the RV while standing on the ground in bare feet..

GFCIs are just an extension of safety features, they are actually reliable and the technology has matured greatly..

GFCIs since they really do not "need" a ground to operate can be EASILY retrofitted into old two wire electrical systems to make those a bit more safe..

I have them in my kitchen, basement, outside and garage for 25 yrs now and zero false trips and non have failed..

I did have one fail in my TT but that was because it was a GFCI with outside exposure under a "in use" cover.. Unit got damp after some heavy rains and died..

[mikestock]

Harvard wrote:
The under lying issue with "unexpected" GFCI tripping from an RV sub system is called "stray capacitance" which allows for stray current leakage. Every foot of wire has some stray capacitance and some loads have RFI capacitors across their AC input circuits. All this "Normal Capacitance" soon adds up to be a 5 mA current leakage.

Is there a solution? I actually tried using a portable battery charger to maintain house batteries but it has "smart" features that somehow won't reliably keep my house batteries charged. I attached at the point they feed the inverter with 12v. It gave me an error.

[Harvey51]

Would it be fair to suggest that the safety ground system is a waste of copper when all circuits are GFCI protected? If the cost of copper and electrician labour keeps rising it may become cheaper to go with GFCI breakers instead of ground wiring.

[DrewE]

Harvard wrote:
The under lying issue with "unexpected" GFCI tripping from an RV sub system is called "stray capacitance" which allows for stray current leakage. Every foot of wire has some stray capacitance and some loads have RFI capacitors across their AC input circuits. All this "Normal Capacitance" soon adds up to be a 5 mA current leakage.

That is assuming you don't have a neutral/ground fault somewhere in the RV wiring, or a bad water heater element, or a bad fridge element, or water intrusion in some electrical box, or some other problem.

It takes hundreds of feet of Romex to get sufficient capacitive coupling in the cable to be problematic, somewhere around a few thousand feet I think. The current requirements for electronic devices are no more than 0.5 mA leakage in RFI filters, etc. A properly constructed RV, one with no ground faults, generally should not cause a good quality, properly functioning GFCI to trip. I suspect, albeit without proof, that more than a few RVers have actual electrical problems or faulty appliances that go uncorrected because they chalk things up to "RVs and GFCIs don't work well together" rather than looking to see if there really is a problem to be fixed.

(I'm also a little surprised the NEC doesn't require GFCI protection for outdoor RV receptacles as they do for standard outdoor receptacles.)