GFCIs and EGCs

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mbrooke

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Try to explain that "flaw" to the countless people who've had a GFCI shut off the power to the two wire, or two wire plus EGC, apparatus that has faulted to their body, and get them to believe their experience (that likely saved their life) was a result of flawed policy and was bad.

Please explain how the appliance faulted to their body. Yes, GFCI cut the power to two wire appliances because that is there job in the absence of an EGC.
 

mbrooke

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I can think of an exception, a memorable one. I picked up the middle of an outdoor extension cord and got shocked. No visible problem with the insulation. Since I was able to let go, it must have been a fairly high resistance. Whatever was wrong wasn't leaking enough current to trip an OCPD. Oh, wait, I see your point. If that high-resistance fault had been to the metal skin of an appliance, and if there had been an EGC, the appliance case would have been close to the same potential as the dirt I was standing in.


An extension cord is an exception, and I can see your point where in this case it would save lives. But outside of that an EGC is still superior.

I am hearing from people on this forum that GFCIs can help with a high resistance fault inside an appliance to its case that has a functioning EGC. And I do agree that is a real scenario, GFCIs catch faults before they evolve into a full blown short circuit. However, that begs a huge question. Why doesn't the CMP require GFCIs at the point of branch circuit origin? I mean think, if high resistance faults are a concern in appliances, then why not all branch circuit wiring?
 

kwired

Electron manager
Location
NE Nebraska
An extension cord is an exception, and I can see your point where in this case it would save lives. But outside of that an EGC is still superior.

I am hearing from people on this forum that GFCIs can help with a high resistance fault inside an appliance to its case that has a functioning EGC. And I do agree that is a real scenario, GFCIs catch faults before they evolve into a full blown short circuit. However, that begs a huge question. Why doesn't the CMP require GFCIs at the point of branch circuit origin? I mean think, if high resistance faults are a concern in appliances, then why not all branch circuit wiring?
I think you will find a much larger number of damaged or missing EGC's in appliance cords, extension cords, plug strips, etc. then you will find in permanent wiring. This is also why the bulk of GFCI protection requirements effect 15 and 20 amp 120 volt receptacle outlets and not so much for other items. Then place those receptacle outlets near areas that are often wet or damp or typically have a lot of grounded surfaces nearby and you have some higher risk for shock incidents.
 

mbrooke

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United States
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Technician
I think you will find a much larger number of damaged or missing EGC's in appliance cords, extension cords, plug strips, etc. then you will find in permanent wiring. This is also why the bulk of GFCI protection requirements effect 15 and 20 amp 120 volt receptacle outlets and not so much for other items. Then place those receptacle outlets near areas that are often wet or damp or typically have a lot of grounded surfaces nearby and you have some higher risk for shock incidents.


I have to agree with this one. Code has gone after cord and plug connected items far more than hard wired machines.
 

al hildenbrand

Senior Member
Location
Minnesota
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Electrical Contractor, Electrical Consultant, Electrical Engineer
Please explain how the appliance faulted to their body. Yes, GFCI cut the power to two wire appliances because that is there job in the absence of an EGC.
This rhetorical device should be beneath you, as, as you know, the Article 100 Definition of Ground Fault is the answer, as it is at the heart of a Class A GFCI's use.

An extension cord is an exception, and I can see your point where in this case it would save lives. But outside of that an EGC is still superior.

I am hearing from people on this forum that GFCIs can help with a high resistance fault inside an appliance to its case that has a functioning EGC. And I do agree that is a real scenario, GFCIs catch faults before they evolve into a full blown short circuit. However, that begs a huge question. Why doesn't the CMP require GFCIs at the point of branch circuit origin? I mean think, if high resistance faults are a concern in appliances, then why not all branch circuit wiring?
Why? Go read the Definition.
Article 100 Definitions
Ground Fault Circuit Interrupter (GFCI).
Ground-Fault Circuit Interrupter (GFCI). A device intended for the protection of personnel that functions to deenergize a circuit or portion thereof within an established period of time when a current to ground exceeds the values established for a Class A device.
In a nutshell, you are tilting against an enforceable NEC language expressed CMP, et.al., intention to protect people, by trying to remove it to protect property, in the process of which you are ignoring the very definition of the GFCI that your OP says you want to lessen the use of.
 

al hildenbrand

Senior Member
Location
Minnesota
Occupation
Electrical Contractor, Electrical Consultant, Electrical Engineer
But my point isn't fighting whats already in the code, rather what can be changed to improve it.
OK.

Most of the NEC is focused on the Premises Wiring (System) - see Article 100, especially the last part of the definition that describes what the Premises Wiring (System) is not.

From what I can determine about your interest in this thread, you are focusing a lot on Utilization Equipment - see Article 100.

As a general rule (although there are some exceptions), wiring on the Utilization Equipment side of the Outlet (again, see Article 100 for the definition of Outlet) is part of a manufacturer's assembly and is not regulated by the National Electrical Code, but, rather, by product standards in other regulatory language, that the manufacturer must follow.

So, in my opinion, the NEC is not the place to change the manufacturer's standards to effect what I can understand of your thinking.
 

mbrooke

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Location
United States
Occupation
Technician
OK.

Most of the NEC is focused on the Premises Wiring (System) - see Article 100, especially the last part of the definition that describes what the Premises Wiring (System) is not.

From what I can determine about your interest in this thread, you are focusing a lot on Utilization Equipment - see Article 100.

As a general rule (although there are some exceptions), wiring on the Utilization Equipment side of the Outlet (again, see Article 100 for the definition of Outlet) is part of a manufacturer's assembly and is not regulated by the National Electrical Code, but, rather, by product standards in other regulatory language, that the manufacturer must follow.

So, in my opinion, the NEC is not the place to change the manufacturer's standards to effect what I can understand of your thinking.


It is one of many and I think everyone gets that. Notice this:


If all metal cased appliances were mandated by UL and the NEC requiring


I mentioned UL. Yes I could have mentioned others but that's beside the point.
 

iwire

Moderator
Staff member
Location
Massachusetts
If all metal cased appliances were mandated by UL and the NEC requiring

I am still waiting to find out how you will mandate the EGC to stay intact.

Broken EGCs are the very reason metal cased, cord and plug connected, commercial kitchen equipment is being plugged into GFCIs.

As is the same with vending machines .....
 

mbrooke

Batteries Included
Location
United States
Occupation
Technician
I am still waiting to find out how you will mandate the EGC to stay intact.

Broken EGCs are the very reason metal cased, cord and plug connected, commercial kitchen equipment is being plugged into GFCIs.

As is the same with vending machines .....


Simple, design outlets with shutters so if no ground pin is present then the live and neutral slots will not open, see pic :p;) (Ok that would be impractical for us consider 2 prongs are still around)


I do agree with you, this is one place where mandating something will not guarantee it staying intact. Or the use of cheater pins with extension cords.
 

romex jockey

Senior Member
Location
Vermont
Occupation
electrician
So to synopsize...

we've no assurances of manufacturers slipping poorly grounded and/or ungrounded appliances through our NRTL's , CSPC or other oversight agencies

we've also no assurance, other than initial visual (nothing required to be megged) inspections of any particular new construction dwelling's ECG. in fact, we've many dwellings still ticking along w/o ECG's at all who've had modern appliances (be them cord cap OR hardwired) introduced.

The NEC's response is simply point of use protection , albeit needs stating OCPD manufacturers are now providing more protective elements for branch circuitry as well.

~RJ~
 
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