Why GFCIs were mandated- a personal perspective

[Greg1707]

Bonding, EGC, Three prong

Bonding, EGC, Three prong

Just a observation from someone who has very little knowledge about this subject. It seems that about the time EGCs were required for all branch circuits, double insulated tools and plastic boxes were commonplace. These days, other than large appliances, very few household devices are supplied with three prong receptacles. Furthermore, most boxes used in residential are plastic--non conductive.

 

[mbrooke]

I remind you the bonding discussed in that is not an EGC.

Its not- but in some ways it is.

But lets move forward to 2014. Why is it that the NEC allows you to ditch the GFCIs when an assured grounding program is used on a job site?

 

[peter d]

Come on have some real fun with it.

:roll::happyno::rant::rant::rant::rant:

 

[iwire]

Its not- but in some ways it is.

No, it is not. It is not even required to be connected to the panel supplying the circuit.

Saying it is the same is the same as saying the neutral is the same as an EGC.

 

[mbrooke]

No, it is not. It is not even required to be connected to the panel supplying the circuit.

True, its not required. But even when its not, it is still a 3rd method in mitigating a live wire hazard.

Saying it is the same is the same as saying the neutral is the same as an EGC.

Contingency management and code aside, they are the same.

 

[iwire]

But lets move forward to 2014. Why is it that the NEC allows you to ditch the GFCIs when an assured grounding program is used on a job site?

I think you need to check the NEC on that one.

There is no 'assured grounding program' for the 125 volt 15, 20 and 30 amp circuits on a job site.

(That option is available to industrial with qualified supervision etc)


I suspect the assured grounding program was left as an option for circuits greater than 125 volt 15-30 amps due to the availability of GFCI devices.

Say I have to hook up a 50 amp 480 volt concrete saw. Where am I getting a GFCI for that equipment?

 

[iwire]

True, its not required. But even when its not, it is still a 3rd method in mitigating a live wire hazard.





Contingency management and code aside, they are the same.

I am not going to continue with this part of the thread. We were taking about EGCs. You want to make a pool bonding conductor an EGC. It is not

 

[mbrooke]

I think you need to check the NEC on that one.

There is no 'assured grounding program' for the 125 volt 15, 20 and 30 amp circuits on a job site.

(That option is available to industrial with qualified supervision etc)


I suspect the assured grounding program was left as an option for circuits greater than 125 volt 15-30 amps due to the availability of GFCI devices.

Say I have to hook up a 50 amp 480 volt concrete saw. Where am I getting a GFCI for that equipment?

But it is mentioned in the code:

590.6 B

(B) Use of Other Outlets. For temporary wiring installations,
receptacles, other than those covered by 590.6(A)(1)
through (A)(3) used to supply temporary power to equipment
used by personnel during construction, remodeling,
maintenance, repair, or demolition of buildings, structures,
or equipment, or similar activities, shall have protection in
accordance with (B)(1) or the assured equipment grounding
conductor program in accordance with (B)(2).

(1) GFCI Protection. Ground-fault circuit-interrupter protection
for personnel.

(2) Assured Equipment Grounding Conductor Program.
A written assured equipment grounding conductor
program continuously enforced at the site by one or more
designated persons to ensure that equipment grounding
conductors for all cord sets, receptacles that are not a part
of the permanent wiring of the building or structure, and
equipment connected by cord and plug are installed and
maintained in accordance with the applicable requirements
of 250.114, 250.138, 406.4(C), and 590.4(D).
(a) The following tests shall be performed on all cord
sets, receptacles that are not part of the permanent wiring of
the building or structure, and cord-and-plug-connected equipment
required to be connected to an equipment grounding
conductor:
(1) All equipment grounding conductors shall be tested for
continuity and shall be electrically continuous.
(2) Each receptacle and attachment plug shall be tested for
correct attachment of the equipment grounding conductor.
The equipment grounding conductor shall be connected
to its proper terminal.
(3) All required tests shall be performed as follows:
a. Before first use on site
b. When there is evidence of damage
c. Before equipment is returned to service following
any repairs
d. At intervals not exceeding 3 months
(b) The tests required in item (2)(a) shall be recorded
and made available to the authority having jurisdiction.

 

[mbrooke]

I am not going to continue with this part of the thread. We were taking about EGCs. You want to make a pool bonding conductor an EGC. It is not

I don't have to make it an EGC- when its not an effective fault current path it is protecting people via equal potential.


Edit: I can see now bring up equal potential was a poor example and side tracking my original claims- but it still supports my claim that GFCIs are not used to prevent an explosive melt down in water like many tend to believe. And yahhh, I screwed my defense up big time :lol::ashamed1:

 

[al hildenbrand]

They (GFCIs) were created and mandated soley to address the issues asociated with missing EGCs. Not water or moisture.

I find this conclusion to be a disturbing misdirection.

Load current is intended to stay in an insulated, and contained, path, from the source, through the load and back to the source. Detection of leakage of current, and the interruption of the leakage current, from that intended path is the purpose of the GFCI. Period.

 

[iwire]

But it is mentioned in the code:

590.6 B

:?



Yes, and as I said it seems the only reason the assured grounding program is an option vs a GFCI for circuits greater than 125 volts 30 amps is lack of GFCI availability for all circuits. In other words they cannot requires what does not exist.

 

[mbrooke]

:?



Yes, and as I said it seems the only reason the assured grounding program is an option vs a GFCI for circuits greater than 125 volts 30 amps is lack of GFCI availability for all circuits. In other words they cannot requires what does not exist.

Wait, where does it say greater than 125 volts? :blink: It should not because part A still stands as an over-rule:

Exception: In industrial establishments only, where conditions
of maintenance and supervision ensure that only
qualified personnel are involved, an assured equipment
grounding conductor program as specified in 590.6(B)(2)
shall be permitted for only those receptacle outlets used to
supply equipment that would create a greater hazard if
power were interrupted or having a design that is not compatible
with GFCI protection.

 

[al hildenbrand]

. . .I have realized that few know the reasoning (in depth) behind why GFCIs were mandated. . .

So pushing aside everything you know about GFCIs, they were simply- and still are- another type of EGC. They were created and mandated soley to address the issues asociated with missing EGCs. Not water or mositure.

I find this conclusion to be a disturbing misdirection.

Load current is intended to stay in an insulated, and contained, path, from the source, through the load and back to the source. Detection of leakage of current, and the interruption of the leakage current, from that intended path is the purpose of the GFCI. Period.

I do not have the 62 NEC on hand, but from this link (which sadly has been hacked to advertise_ahemm_certain personal assistance- :rant::rant::rant::rant:, but added to show proof of where I quoted from)

http://www.necconnect.org/resources/gfcis/

The first mention of ground-fault protection occurred in the 1962 NEC with the introduction of Article 680 for swimming pools. It is generally accepted that electricity and water are not a good combination, and there was a concern for the shock hazard associated with underwater lighting. An approved fail-safe ground detector device could automatically de-energize the circuit for underwater lighting operating at greater than 30 volts. This fail-safe ground (not yet called GFCI) detector was not the only allowable method; an approved grid structure or similar safeguard was an alternative.

In this case bonding was an equal option to a GFCI.

Your own source defeats your primary conclusion of your OP.

As an aside, as one who grew up with electronics in the late fifties and on, it is important to recall, now, from our electronics rich appliances, hardware and toys, just how NEW solid state devices were in the Code Making Process window of time ('59-'62) leading up to the published 1962 edition of the NEC. Tube circuitry (voltage amplification) was giving way to discreet component solid state circuitry (current amplification), and solid state digital switching was also largely discreet components (single transistors soldered to circuit boards). Any solution of the grand concept of an "approved fail-safe ground detector" would have been enormous compared to today's svelte and compact $11 Class A GFCI receptacle.

 

[mbrooke]

Your own source defeats your primary conclusion of your OP.

Not a good combination, which could mean anything- up to an including that an energized lamp shell in water is a no-no.

As an aside, as one who grew up with electronics in the late fifties and on, it is important to recall, now, from our electronics rich appliances, hardware and toys, just how NEW solid state devices were in the Code Making Process window of time ('59-'62) leading up to the published 1962 edition of the NEC. Tube circuitry (voltage amplification) was giving way to discreet component solid state circuitry (current amplification), and solid state digital switching was also largely discreet components (single transistors soldered to circuit boards). Any solution of the grand concept of an "approved fail-safe ground detector" would have been enormous compared to today's svelte and compact $11 Class A GFCI receptacle.

At 30ma they could have made them electromechanical

 

[iwire]

Wait, where does it say greater than 125 volts? :blink: It should not because part A still stands as an over-rule:

Lets start here

590.6 Ground-Fault Protection for Personnel. Groundfault
protection for personnel for all temporary wiring installations
shall be provided to comply with 590.6(A) and
(B). This section shall apply only to temporary wiring installations
used to supply temporary power to equipment
used by personnel during construction, remodeling, maintenance,
repair, or demolition of buildings, structures,
equipment, or similar activities. This section shall apply to
power derived from an electric utility company or from an
on-site-generated power source.

Th above tells us we have to comply with both A & B, not one or the other.

(A) Receptacle Outlets. Temporary receptacle installations
used to supply temporary power to equipment used by
personnel during construction, remodeling, maintenance,
repair, or demolition of buildings, structures, equipment, or
similar activities shall comply with the requirements of
590.6(A)(1) through (A)(3), as applicable.

The above lays out what activities this applies to and what sections we have to comply with

Exception: In industrial establishments only, where conditions
of maintenance and supervision ensure that only
qualified personnel are involved, an assured equipment
grounding conductor program as specified in 590.6(B)(2)
shall be permitted for only those receptacle outlets used to
supply equipment that would create a greater hazard if
power were interrupted or having a design that is not compatible
with GFCI protection.

That is the very limited exception to the GFCI protection required by section (A).

(A)(1) Receptacle Outlets Not Part of Permanent Wiring.
All 125-volt, single-phase, 15-, 20-, and 30-ampere receptacle
outlets that are not a part of the permanent wiring of
the building or structure and that are in use by personnel
shall have ground-fault circuit-interrupter protection for
personnel.

(A)(1) above applies unless you fit the narrow limitations of the exception above. No assured grounding program allowed for those receptacles.

Now lets move on to (B) where we can find the assured grounding program.

(B) Use of Other Outlets. For temporary wiring installations,
receptacles, other than those covered by 590.6(A)(1)
through (A)(3) used to supply temporary power to equipment
used by personnel during construction, remodeling,
maintenance, repair, or demolition of buildings, structures,
or equipment, or similar activities, shall have protection in
accordance with (B)(1) or the assured equipment grounding
conductor program in accordance with (B)(2).

(1) GFCI Protection. Ground-fault circuit-interrupter protection
for personnel.

(2) Assured Equipment Grounding Conductor Program.
A written assured equipment grounding conductor program
continuously enforced at the site by one or more designated
persons to ensure that equipment grounding conductors for
all cord sets, receptacles that are not a part of the permanent
wiring of the building or structure, and equipment connected
by cord and plug are installed and maintained in
accordance with the applicable requirements of 250.114,
250.138, 406.4(C), and 590.4(D).

So section (B) does not apply to any 125 volt, 15, 20 and 30 amp receptacles and therefore the assured equipment grounding program cannot be used for those receptacles.

Assured equipment grounding can only be used in place of GFCI for circuits greater than 30 amps and 125 volts.

 

[al hildenbrand]

Not a good combination, which could mean anything- up to an including that an energized lamp shell in water is a no-no.

Sure. That is an instance. But it is not the continuum of what "current leakage from the insulated circuit path" covers. What about all manner of mis-wiring? What about an open neutral with the live conductor short to EGC connected exposed metal in the hands of a person working on the end of a long small guage branch circuit and extension cord, a person who is exposed to an intimate connection with Earth?

In this scenario, the GFCI detection is absent, but there is a good EGC. Circuit analysis yields a whooping 56 mA through body "leak".

 

[user 100]

I think they were concerned with the lack of them in tools/appliances before the shift to open or missing EGCs. The fact so many metal cased tools/appliances existed in the 50/60s and 70s makes for a very compelling argument that electrocutions were predominantly driven by standing ground faults.

Your own source defeats your primary conclusion of your OP.

As an aside, as one who grew up with electronics in the late fifties and on, it is important to recall, now, from our electronics rich appliances, hardware and toys, just how NEW solid state devices were in the Code Making Process window of time ('59-'62) leading up to the published 1962 edition of the NEC. Tube circuitry (voltage amplification) was giving way to discreet component solid state circuitry (current amplification), and solid state digital switching was also largely discreet components (single transistors soldered to circuit boards). Any solution of the grand concept of an "approved fail-safe ground detector" would have been enormous compared to today's svelte and compact $11 Class A GFCI receptacle.

Yeah, gfci FWIHR, was invented in 1961.... but it was NOT available yet for the average consumer pool installation, as it wasn't commercially viable. Computers were available then too, but how many folks had one, let alone afford one?

GFCI was available by the end of that decade b/c of the minutarization the occurred w/ electronics.

To me, the why for the expansion of gfci is simple: Electrocution from leakage current, whatever the source, was a problem, which the NEC had no good solution for and could not be solved by expanding the EGC requirements and so once a reliable ,effective, and practical device was available to detect/interrupt leakage current- the NEC simply mandated its use, nothing more, nothing less.

 

[peter d]

Sure. That is an instance. But it is not the continuum of what "current leakage from the insulated circuit path" covers. What about all manner of mis-wiring? What about an open neutral with the live conductor short to EGC connected exposed metal in the hands of a person working on the end of a long small guage branch circuit and extension cord, a person who is exposed to an intimate connection with Earth?

In this scenario, the GFCI detection is absent, but there is a good EGC. Circuit analysis yields a whooping 56 mA through body "leak".

Only an engineer turned electrician would come up with something like that.

 

[kwired]

I would guess the history behind GFCI requirements for temporary power and especially temporary power for construction started mostly with just 15 and 20 amp 120 volt receptacles. That is likely the conditions where the majority of incidents were occurring. Missing or compromised EGC's in extension cords or tool cords was likely a common factor as well - and the reason for allowing assured grounding monitoring programs - but most probably find having GFCI to be much easier and less cost then to operate such a monitoring program.

There have been expanded requirements over the years so it is more then just 15/20 amp 120 volt applications that require GFCI for temp power, but still is not everything. I still don't have a 2017, but seem to recall there was some expanded GFCI requirements for temp installations, anyone know for certain?

 

[thatssobs97]

What is EGC?...Sorry, I'm an apprentice trying to learn

Sent from my SM-G930P using Tapatalk