In the U.S. we have arc fault circuit breakers and ground fault current interruptors.
Some say they are prone to nuisance tripping (false positives).

I have not been able to get specific data for the U.S. on how lives were saved by these devices or how many lives were lost by not using these things.

What countries besides the U.S. have these things?

Have they helped save lives or just cost money that could have been better spent?

 

Don't know about the statistics but do know I tripped one once when I accidentally touched a live plug as I was unplugging a cord. May have saved me but, of course, there's no way to prove that and still keep me alive.

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Carl

 

How many dead people does it take to make them worth the money?

Code only requires them in areas where water might come in contact with electricty. That is a very good idea. Worth ever cent.

It would be interesting to know how many people would not have died last year if they had been using an outlet equiped with one.

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Yes GFIs are prone to false positive tripping sometimes and yes I have no doubt they have saved lives. How many? who cares, they are pretty inexpensive these days due to high volume use and production. Once they were a little pricey before widespread code requirements came into being.

In the USA code requirements are usually passed and enforced at the city or county government level although they do tend to follow federal, state or industry rules, laws, guidlines and recommendations.

Lefty

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I'm guessing it's pretty much the same deal as motorcycle helmets, airbags, and seat belts. In some situations they might reduce injuries, or even save lives. But on the other hand, they might make little or no difference, could even cause greater problems. If you absolutely trust that these devices will protect you, some people tend to be a little more careless. Ever notice that the media never mentions when a fatality was wearing the seat belt, but always when they don't. Same deal when some one walks away from a bad crash, they don't mention the seat belt if it wasn't used, but give praise if they did wear it. Just seems a little strange, I don't wear it (unless I'm getting pulled over ), and have an interest in how effective they are. The spotty reporting kind of sticks out. Air bags, well if you've seen the road-rash type friction burns... often the only injury in minor accidents, not a real great idea for most drivers. Motorcycle helmets are great, but they can also be the cause of neck injuries an death. I wouldn't ride without on myself, mostly for the bug shield though.

I've heard that you can still get zapped before it trips, the good part is that you don't stay connected. Have also heard they fail to work after a few years.

Personally, I don't rely on these safety devices, but my own common sense for protection. I think there is only a small increase in safety. I know that water and electricity don't mix, and won't believe it will ever be safe to use power tools in the rain, or hop in the hot tub during a thundershower. Unplug the extension cord from the outlet first, then go outside one the wet grass to wind it up...

 

My HotTub has one and it was expensive as it is a 40A 220VAC double pole unit. It has never tripped yet as there has been no faults in the Tub or wiring. I wouldn't go in a HotTub without one. My life is worth more than $80.
They are mandatory in Canada in the kitchen, bathroom, outside, or anywhere there is a possibility of touching water/plumbing and things powered from the outlet at the same time. The one connected to the outside outlets in my house failed. For $15 retail I replaced it.
We also have them on the work benches at work. They have saved many a scope probe from sleepy technicians.

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GFI's are a no brainer in wet environments, or on circuits that have high current potential near conductive surfaces.

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So far, so good. . .anyone have any input from outside North America?

 

Ahh now it's our turn

Here in cambodia there is no law for it and if there whas one than it didn't matter either

the new buildings that are contsructed by or for international non chinasian companies are folowing the international standard with MCBs MCCBs and surge protections earth leakeage protections

the rest of everything constructed is plain unsafe and stupid

or it is made with to much wire devices and everything what you can imagin but half of the time it's not even conected

That's the story when you go to the shop as a noob and ask i need electrical in my house and you admit that you are a noob

o yeah you do pay to much this way

the otherway is that you pretend that you know it all and do it your self
this ends up in buing to less of everything and than conect it in a way that you think it works but it doesnt

I have seen systems that have voltage drops in the same system (original 220V but some places in the house 160V when you swich on the fridge ) suplly lines where 0.75 sqr mm speaker cable (think of the insulation protection properties of speaker cable)

houses do burn off quite regulary due to electrical shorts

if you run a exstention than you just twist an extra wire and tape it with some cello tape

calling the electrician is also not a guaranty as quite a few fry themself here and it does take some hours to get the body out of the pole (he whas busy to make an iligal conection to get free juice) (of coarse that way you don't controll the switch)
not a joke is hapening here

when i move into a new house i install my self all earth leakage devices in that house
i also check if my neighbours dont steel power from me
otherwise i can be triped and not by my fault that would make it realy irritating

Robert-Jan


people do die here from electricity but it's more because of stupidity

 

They are EXTREMELY worthwhile devices, if an Earth Leakage Trip (GFI) trips, it's generally because there's been a leak to earth - I've never known them trip without any reason.

BTW, in the service department at work we don't have any GFI or anything similar, maintaining an earth free environment makes it reduntant, and safer still.

As for MCB's (Miniture Circuit Breakers) instead of fuses, they tend to be FAR too sensitive, but aren't in any way for personal safety anyway. Given the choice I would (and do) still use fuse wire instead of MCB's.

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Here in England GFIs are called ELCBs (Earth Leakage Circuit Breakers).

I think that they are mandatory in new buildings for any socket likely to supply power outside of the house, so anything on the ground floor.

It is common practice to feed all the sockets from one, but not the lights. Sometimes the cooker isn't fed from and ELCB because of fear of nuisance trips, and I have seen fridges on circuits not fed from an ELCB to reduce the damage if one trips and the owner is away.

The lights are not on an ELCB as there is less risk of a shock from lights and the danger of not being able to see to get out if all the lights fail.

I think a lot of that is over-cautious, and I have everything on an ELCB. I do have one for lights and one for everything else, as it is easier to see my way to the circuit breakers by the light of the TV etc. than nothing.

 

You can get MCBs rated for surges, LPA Channel do them.

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Yes that's right

the MCB comes with different curves wich you can compare with a FF fuse to a S fuse

the normal one that is most used (at least here in resedential envoirements) is a C curve that compares in speed to an avarage fuse

Robert-Jan

 

Reminds me of when I lived in the Philippines and rented a small dwelling. The AC power for lighting just sort of dangled from the ceiling with a U shapped nail holding the wire in place. When I opened the circuit breaker there were large metal strips in place of fuses. In fact one of the fuses had been replaced with a 1 Peso coin...

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The only "nuisance trip" I've ever had with a GFCI was when plugging in a 100-foot extension cord (no load attached). I assumed that what had happened was that ground and hot connected before the neutral while the power waveform was near peak and capacitance caused a "ground fault" current high enough and of a long enough duration to trip the unit. But it's only happened once.

Dean

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Dean Huster, Electronics Curmudgeon
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