GFCIs and EGCs

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mbrooke

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If all metal cased appliances were mandated by UL and the NEC requiring a 3 prong plug, would GFCI requirements still be as necessary in some places?
 

GoldDigger

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I would think that would result in more GFCIs..
I can see it resulting in more GFCI trips. :)

The GFCI offers protection in case the EGC path becomes compromised for any reason.
Without the GFCI an internal leakage will not be detected as it grow larger and larger. (No warning "It feels kind of funny when I touch the surface of the appliance" which will usually not kill you (yet).)
 

mbrooke

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But is begs the question, if an EGC is present are GFCI really needed outside of anything other than a pool or sink?
 

augie47

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My first thought centers on how many cords I have seen with missing or broken ground prongs.
 

iwire

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If all metal cased appliances were mandated by UL and the NEC requiring a 3 prong plug, would GFCI requirements still be as necessary in some places?

I would think that would result in more GFCIs..


Sorry for the long delay, was working late.

But is begs the question, if an EGC is present are GFCI really needed outside of anything other than a pool or sink?

Yes.

Consider this, most all commercial kitchen appliances are metal cased cord and plug connected with an EGC yet the NEC only fairly recently added GFCI requirements for commercial kitchens.

Why did they add this requirement for grounded equipment?

Because there had been electrocutions of kitchen workers from these items. An EGC is only good as long as it is connected and ground pins break, cords get damaged etc.


On the other hand if all appliances were required to be doubly insulated I think the need of GFCIs would decrease.
 
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mwm1752

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But is begs the question, if an EGC is present are GFCI really needed outside of anything other than a pool or sink?

you seem to be on a GFCI mission lately -- certainly rules & code can be excessive even though we define them as minimum. I would hate to be the responsible party, that ignored a life safety install, resulting in harming someone, in that 1-1,000,000 circumstance it was inserted in the code for. Just wondering what your issue - no safety factors? - cost? - inconvienience?
 

mbrooke

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Sorry for the long delay, was working late.



Yes.

Consider this, most all commercial kitchen appliances are metal cased cord and plug connected with an EGC yet the NEC only fairly recently added GFCI requirements for commercial kitchens.

Why did they add this requirement for grounded equipment?

Because there had been electrocutions of kitchen workers from these items. An EGC is only good as long as it is connected and ground pins break, cords get damaged etc.


On the other hand if all appliances were required to be doubly insulated I think the need of GFCIs would decrease.

But that's my point. EGC reduces the need for GFCI. If 3 prong plugs were required for tools and toasters the GFCI requirement could be put off or would have come latter.
 

mbrooke

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you seem to be on a GFCI mission lately -- certainly rules & code can be excessive even though we define them as minimum. I would hate to be the responsible party, that ignored a life safety install, resulting in harming someone, in that 1-1,000,000 circumstance it was inserted in the code for. Just wondering what your issue - no safety factors? - cost? - inconvienience?

Forgive me for trying to understand the reasoning behind our codes. Its a shame when a free mind is misinterpreted as malice. :(
 

iwire

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But that's my point. EGC reduces the need for GFCI.

But this assumes EGCs stay intact and the reality has been proven time and time again they do not stay in tact.

It seems you have made your mind up and are ignoring real life.

If 3 prong plugs were required for tools and toasters

In many cases they are required and yet they have still killed folks.

I really do not understand where you are going with this. GFCI is a proven, inexpensive technology that has likely saved a great many people from death.

We could also say OCPDs are not needed if we assume electrical systems did not fail.
 

mbrooke

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But this assumes EGCs stay intact and the reality has been proven time and time again they do not stay in tact.


Correct, but assuming EGCs did stay intact that would prove that its an absent EGC that GFCIs protect against (in some cases) rather than water as everyone assumes.




It seems you have made your mind up and are ignoring real life.

:huh:







In many cases they are required and yet they have still killed folks.

That is correct. And personally where an LCID rains supreme to a GFCI.



I really do not understand where you are going with this. GFCI is a proven, inexpensive technology that has likely saved a great many people from death.

We could also say OCPDs are not needed if we assume electrical systems did not fail.

If electrical systems did not fail breakers would not be needed, correct. But they do fail.

In fact glowing connections are just as much of a hazard, but why isn't anything there to stop them? GFCI can prevent fires when implemented at the branch circuit origin but aren't.

I just want to know the reasoning behind the code. I am at this point where I want to know why, not just assume because truth is I can wire a building but know nothing about electrical theory.
 

don_resqcapt19

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But that's my point. EGC reduces the need for GFCI. If 3 prong plugs were required for tools and toasters the GFCI requirement could be put off or would have come latter.
I can't see the elimination of the EGC for any cord and plug connected equipment.

The original GFCI rules were all based on cord and plug connected equipment it wet areas. The loss of the EGC along with a more conductive wet area or surface increases the shock hazard.

Now they are being used in more applications and for purposes other than limiting the duration of the shock, the new dishwasher requirement is an example of the GFCI being used for another purpose...the purpose of that rule is not to limit the shock duration, but to prevent fires.

I don't really have a problem with the expansion of the GFCI requirements as they do what they say they can do...now on the other hand, I have seen no evidence that the AFCI can do what they say it can and have never been supporter of the AFCI requirement.
 

mwm1752

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Location
Aspen, Colo
Then what would a healthy response be?

It's ok to play devils advocate to expand your knowledge - I do the same sometimes. Sometimes a reason for the question can narrow down an interpretation that can be accepted or fuel for rebuttal. I know from 1st hand experience no one walks on egg shells when it comes to answers.
 

al hildenbrand

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Minnesota
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But that's my point. EGC reduces the need for GFCI.
I tend to see this as part of the historical progression of increasing "safety" to attempt to prevent fewer and fewer harmful events.
  1. Ground the generator frame.
  2. Connect the Premises Wiring (System) to the metallic water piping system.
  3. Require Equipment Grounding Conductor (EGC).
  4. Require Ground Fault Circuit Interruption.
  5. Require Arc Fault Circuit Interruption.

At this point, in the early 21st Century, we are chasing fewer and fewer harmful events with more and more requirements.

When considering changing a two wire ungrounded appliance to an appliance with an EGC, one is extending the level a safety in #3 above, so one is technically increasing the safety at the appliance.

However, GFCI has, historically, been required to be added to branch circuits (in new construction) that already have EGCs present. . . that is, the GFCI is added to the EGC because even more safety for personnel is achieved.

Whether the EGC extends from the branch circuit to the utilization equipment, or not, doesn't really affect the overall increase of safety for personnel that comes only with the addition of the GFCI to the outlet, IMO.
 

ggunn

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In fact glowing connections are just as much of a hazard, but why isn't anything there to stop them?
How would you do that? How would a device at the panel know the difference between a series glowing fault in the wiring of a branch circuit and a toaster plugged into an outlet on that circuit?
 

tom baker

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Staff member
But is begs the question, if an EGC is present are GFCI really needed outside of anything other than a pool or sink?

Absolutely! A GFCI does not require an EGC to operate. The NEC started requiring EGCs in the mid 60s' but we still saw in increase in shocks and deaths.
Even with a EGC, a 20 amp breaker on a line to case fault, won't trip at 20 amps, or even 25 amps.
GFCIs are a proven life saving device.
 
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