Class-A GFCI's are not well suited

[kwired]

Notice my use of "GFI", not GFCI







http://scn.industries.ul.com/blog/2017-nec-changes-have-been-announced






True, but you did hint by using it in context. Machines of all sizes can suffer an open EGC. Which brings me to the point I am trying to present to Mr. Zappa. Open EGCs are the primary driver behind GFCIs and SPGFCIs, not the other way around.

And the outlets that NEC required to be protected with GFCI has typically been areas where there maybe has been more statistical deaths or injuries - most because of a compromised EGC. Only more recent years did they start requiring them in places where the statistics were not likely all that high. What was the substantiation that a drinking fountain needs GFCI? How many of you ever run into one with a missing EGC? Sure it is possible, but majority of those are seldom ever unplugged and the risk is much lower then say a portable tool or appliance.

 

[K8MHZ]

hmmm, NEC says EGC is required for GFCI ??

http://www.esgroundingsolutions.com...hnical-reason-to-put-a-gfci-on-a-refrigerator/

The National Electrical Code requires that GFCI systems be grounded to ensure that a low-impedance fault path exists back to the OCPD. However, the GFCI portion of the system will function even without a ground wire; they are simply more susceptible to accidental breaker trips and sensing problems.

Well, we both know that isn't true.

 

[iwire]

hmmm, NEC says EGC is required for GFCI ??

http://www.esgroundingsolutions.com...hnical-reason-to-put-a-gfci-on-a-refrigerator/

hmmm, no that is not what NEC says, that is what your link says

hmmm, no that quote from the link does not say what you think it does either

The National Electrical Code requires that GFCI systems be grounded to ensure that a low-impedance fault path exists back to the OCPD. However, the GFCI portion of the system will function even without a ground wire; they are simply more susceptible to accidental breaker trips and sensing problems.

A GFCI is required to be connected to a grounded source such as a wye supply or corner grounded delta. You cannot use a GFCI on an ungrounded source. That is what the quote you posted is saying.

 

[FionaZuppa]

Well, we both know that isn't true.

correct. only applies to new work.

an aside question: anyone run into issues with class-A GFCI tripping because of the application and not a fault, outside of the common in-home use of class-A GFCI? like an outdoor pump where its a GFCI ocpd, or in general, GFCI w/o receptacle.

hmmm, no that is not what NEC says, that is what your link says

hmmm, no that quote from the link does not say what you think it does either

A GFCI is required to be connected to a grounded source such as a wye supply or corner grounded delta. You cannot use a GFCI on an ungrounded source. That is what the quote you posted is saying.

??
you are saying this is not talking about EGC ??

The National Electrical Code requires that GFCI systems be grounded to ensure that a low-impedance fault path exists back to the OCPD. However, the GFCI portion of the system will function even without a ground wire; they are simply more susceptible to accidental breaker trips and sensing problems.

 

[iwire]

correct. only applies to new work.

No, you misread the quote.

That quote applies to work of any age. GFCIs are not to be used from ungrouned supplies.

an aside question: anyone run into issues with class-A GFCI tripping because of the application and not a fault, outside of the common in-home use of class-A GFCI? like an outdoor pump where its a GFCI ocpd, or in general, GFCI w/o receptacle.

I think some folks have had trouble with florescent lighting.

As far as pumps of the size that are supplied from a 15 or 20 amp 125 volt circuit I have not had issues.

Christmas lights, huge issue. But not really, the GFCI is doing its job, people just let the plugs and receptacles get wet. We had a large commercial property with a ton of holiday lights that kept tripping the GFCIs. Finally one of our guys went to Home Depot and cleaned them out of quality cords, ones that were long enough not to require daisy changing them. That solved that issue.

 

[iwire]

you are saying this is not talking about EGC ??

Pretty much.

The National Electrical Code requires that GFCI systems be grounded to ensure that a low-impedance fault path exists back to the OCPD. However, the GFCI portion of the system will function even without a ground wire;

The red text above is not about an EGC at all. It is about the type of source that the GFCIs are supplied from

The blue text above, is about the not needing an EGC to operate.

 

[kwired]

hmmm, NEC says EGC is required for GFCI ??

http://www.esgroundingsolutions.com...hnical-reason-to-put-a-gfci-on-a-refrigerator/

I issues with several things said on the page your link goes to. Starting with seeming to claim NEC requires GFCI on refrigerators. NEC doesn't specifically require GFCI on refrigerators, however there are many situations where GFCI is required for other reasons and a refrigerator happens to be plugged in there.

I don't believe you must have a grounded system to use a GFCI. On a non grounded system you might develop a ground fault but nothing trips, and there really isn't much hazard at this point either, but upon developing a second ground fault there could be hazardous current situations - a GFCI will still trip if in series with such fault current.

 

[iwire]

I don't believe you must have a grounded system to use a GFCI. On a non grounded system you might develop a ground fault but nothing trips, and there really isn't much hazard at this point either, but upon developing a second ground fault there could be hazardous current situations - a GFCI will still trip if in series with such fault current.

You are killing me 'wired.


From the UL white book, check the last sentence of what I posted.

GROUND-FAULT CIRCUIT
INTERRUPTERS (KCXS)
GENERAL
This category covers ground-fault circuit interrupters (GFCI) for use in
accordance with ANSI/NFPA 70, ‘‘National Electrical Code’’ (NEC).
A GFCI is a device whose function is to interrupt the electric circuit to the
load when a fault current to ground exceeds some predetermined value that
is less than that required to operate the overcurrent protective device of the
circuit.

GFCIs are intended to be used only in circuits where one of the conductors
is solidly grounded.

 

[FionaZuppa]

I issues with several things said on the page your link goes to. Starting with seeming to claim NEC requires GFCI on refrigerators. NEC doesn't specifically require GFCI on refrigerators, however there are many situations where GFCI is required for other reasons and a refrigerator happens to be plugged in there.

I don't believe you must have a grounded system to use a GFCI. On a non grounded system you might develop a ground fault but nothing trips, and there really isn't much hazard at this point either, but upon developing a second ground fault there could be hazardous current situations - a GFCI will still trip if in series with such fault current.

NEC says the GFI is required for fridge unless the recept is on "dedicated" ckt, i assume this to mean a single receptacle (single recept GFCI, or GFCI ocpd w/ single recept) so that there is not a free socket to plug into:

GFCI protection is not required for receptacles that are not readily accessible, such as a ceiling-mounted receptacle for a garage door opener. Nor are they required for a receptacle on a dedicated branch circuit located and identified for a cord-and-plug-connected appliance, such as a refrigerator or freezer.

but lets say GFCI is required for some pool equipment, but at same time the recept is not easily user accessible, why can i not use class-C GFCI if the application doesnt like use of class-A ??

 

[FionaZuppa]

You are killing me 'wired.


From the UL white book, check the last sentence of what I posted.

ok, so, then according to you the grounded CCC is not a requirement of NEC as you stated, its a requirement that UL has stated for GFCI's.
thus your post #26 does not make sense to me.

that quote to me sounds like it is all EGC related, but perhaps not in full context of NEC since there are exceptions. for new installs the quote is certainly 100% true.

 

[iwire]

NEC says the GFI is required for fridge unless the recept is on "dedicated" ckt, i assume this to mean a single receptacle (single recept GFCI, or GFCI ocpd w/ single recept) so that there is not a free socket to plug into:

No, no and no.

You have not even looked at an NEC in a very long time have you?

Since 1971, the NEC has expanded the requirements for ground-fault circuit interrupters (GFCI) to protect anyone who plugs into an electrical system.

GFCI protection is not required for receptacles that are not readily accessible, such as a ceiling-mounted receptacle for a garage door opener. Nor are they required for a receptacle on a dedicated branch circuit located and identified for a cord-and-plug-connected appliance, such as a refrigerator or freezer.

That looks to be a quote from at least 3 or 4 code cycles ago.

but lets say GFCI is required for some pool equipment, but at same time the recept is not easily user accessible, why can i not use class-C GFCI if the application doesnt like use of class-A ??

There is nothing in a modern pool that cannot be operated from a class A GFCI and I am truly blown away that you would look at a pool as the pace to raise the mA level of protection.

If you have pool built before 1965 or so and that has issues you can use a class B if you can find one.

A Class B GFCI with a 20 milliamp trip level is to be used only for protection of underwater swimming pool lighting fixtures installed before adoption of the 1965 National Electrical Code (NEC). When using a Class B GFCI, the swimming pool lighting circuit must be disconnected before servicing or relamping the lighting fixture. Often the electrical equipment in older pools had a leakage current that was greater than the 5 milliamps required for a Class A GFCI and this leakage current would cause nuisance tripping of the circuit. Therefore, a Class B device with a higher trip current was permitted.

http://www.ecmag.com/section/codes-standards/differences-between-gfci-idci-and-gfpe

 

[iwire]

ok, so, then according to you the grounded CCC is not a requirement of NEC as you stated, its a requirement that UL has stated for GFCI's.
thus your post #26 does not make sense to me.

110.3(B) makes it an NEC requirement.

 

[K8MHZ]

Highlighted are the parts I am having trouble with:

The National Electrical Code requires that GFCI systems be grounded to ensure that a low-impedance fault path exists back to the OCPD. However, the GFCI portion of the system will function even without a ground wire; they are simply more susceptible to accidental breaker trips and sensing problems.

 

[iwire]

Highlighted are the parts I am having trouble with:

Its a Q&A page from a private consulting company, I for one am not going to get too hung up on it. It seems clearly written off the cuff, it is certainly no authoritative white paper.

The quote was posted to show that the NEC requires an EGC for GFCI, It fails to do so.

 

[FionaZuppa]

110.3(B) makes it an NEC requirement.

110.3(B) is a back reference , so technically its not a NEC requirement. the requirement is per UL, NEC just has a back reference by way of words.

 

[growler]

OSHA was mentioned, and if you read OSHA 1926.404(b)(1)(iii)(D) you'll see that they demand EGC for GFCI..... seems like they recognize the hazard(s) when there is no EGC.

You really can't compare the safety standards set forth by OSHA to the mimimun standards allowed by the NEC.

I don't keep any MSDS sheets on any of the household cleaners that I have at home because I'm not reqired to as my home is not covered by OSHA.

You can always find a more strict set of standards set for almost anything under certian applications. Everyone agrees that an EGC is better but that it's not required by the NEC as a replacement on an existing ungrounded circuit. What is allowed as a minimum standard is not always the best possible situation but is considered to be safe enough for normal use ( the NEC) but OSHA is allowed to have higher standards for the areas they cover.

 

[kwired]

You are killing me 'wired.


From the UL white book, check the last sentence of what I posted.

That is not NEC though. And it doesn't require system to be grounded, it just recommends it (which will help enhance the performance of the GFCI). Small portable generators are one place where it is common to see a GFCI on an otherwise ungrouned system.

NEC says the GFI is required for fridge unless the recept is on "dedicated" ckt, i assume this to mean a single receptacle (single recept GFCI, or GFCI ocpd w/ single recept) so that there is not a free socket to plug into:


but lets say GFCI is required for some pool equipment, but at same time the recept is not easily user accessible, why can i not use class-C GFCI if the application doesnt like use of class-A ??

Iwire kind of said what I wanted to say - you seem to be going off some older NEC editions, for the most part there hasn't been any "dedicated single receptacles" allowed to be exempt where GFCI was otherwise required for some time now, probably about 2002 or 2005 NEC where that last was allowed.

 

[iwire]

Fiona, here are the 2014 GFCI requirements. Notice very few exceptions remain.

210.8 Ground-Fault Circuit-Interrupter Protection for
Personnel. Ground-fault circuit-interrupter protection for
personnel shall be provided as required in 2IO.S(A) through
(C). The ground-fault circuit-interrupter shall be installed in
a readily accessible 10catiol1.


Informational Note: See 2 \5.9 for ground-fault circuitinterrupter
protection for personnel on feeders.

(A) Dwelling Units. All J 25-volt, single-phase, 15- and
20-ampere receptacles installed in the locations specified in
21O.8(A)(I) through (10) shall have ground-fault circuitinterrupter
protection for personnel.

(1) Bathrooms

(2) Garages, and also accessory buildings that have a
floor located at or below grade level not intended as
habitable rooms and limited to storage areas, work
areas, and areas of similar use

(3) Outdoors

Exception to (3): Receptacles that are not readily accessible
and are supplied by a branch circuit dedicated to
electric snow-melting, deicing, or pipeline and vessel heating
equipment shall be permitted to be installed in accordance
with 426.28 or 427.22. as applicable.

(4) Crawl spaces - at or below grade level

(5) Unfinished basements - for purposes of this section,
unfinished basements are defined as portions or areas
of the basement not intended as habitable rooms and
limited to storage areas, work areas, and the like

Exception to (5): A receptacle supplying only a pennanently
installed fire alarm or burglar alarm system shall
not be required to have ground-fault circuit-interrupter
protection.


lnformational Note: See 760.41(B) and 760.121 (B) for
power supply requirements for fire alarm systems.
Receptacles installed under the exception to
210.8(A)(5) shall not be considered as meeting the
requirements of 210.52(G)

(6) Kitchens - where the receptacles are installed to
serve the countertop surfaces

(7) Sinks - where receptacles are installed within 1.S m
(6 ft) of the outside edge of the sink

(8) Boathouses

(9) Bathtubs or shower stal1s -- where receptacles are
installed within 1.8 m (6 ft).of the outside.edge of the
bathtub or shower stall

(10) Laundry areas

(B) Other Than Dwelling Units. All 125-volt, singlephase,
15- and 20-ampere receptacles installed in the locations
specified in 210.S(B)( 1) through (S) shall have
ground-fault circuit-interrupter protection for personnel.

(1) Bathrooms

(2) Kitchens

(3) Rooftops

(4) Outdoors

Exception No. 1 to (3): Receptacles on rooftops shall not be
required to be readily accessible other than from the
rooftop.

Exception No. 2 to (3) and (4): Receptacles that are not
readily accessible and are supplied by a branch circuit
dedicated to electric snow-melting, deicing, or pipeline and
vessel heating equipment shall be permitted to be installed
in accordance with 426.28 or 427.22, as applicable.

Exception No, 3 to (4): In industrial establishments onl}~
where the conditions of maintenance and supervision ensure
that only qualified personnel are involved, an assured
equipment grounding conductor program as specfied 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 is interrupted or having a design
that is not compatible with G FCI protection.

(5) Sinks - where receptacles are installed within 1.S m

(6 ft) of the outside edge of the sink

Exception No. 1 to (5): In industrial laboratories, receptacles
used to supply equipment where removal of power
would introduce a greater hazard shall be permitted to be
installed without GFCI protection.

Exception No.2 to (5): For receptacles located in patient
bed locations of general care or critical care areas of
health care facilities other than those covered under
210.8(B)(l), GFCI protection shall not be required.

(6) Indoor wet locations

(7) Locker rooms with associated showering facilities

(8) Garages, service bays, and similar areas other than vehicle
exhibition hal1s and showrooms

(C) Boat Hoists. GFCI protection shall be provided for
outlets not exceeding 240 volts that supply boat hoists installed
in dwelling unit locations.

(D) Kitchen Dishwasher Branch Circuit. GFCI protection
shall be provided for outlets that supply dishwashers
installed in dwelling unit locations.

 

[iwire]

That is not NEC though. And it doesn't require system to be grounded, it just recommends it (which will help enhance the performance of the GFCI).

I disagree, but it is irrelevant as that quote Fiona put up was talking about the requirement for a grounded system not an EGC.

 

[FionaZuppa]

I disagree, but it is irrelevant as that quote Fiona put up was talking about the requirement for a grounded system not an EGC.

i am not sure it was, and NEC doesnt actually state it as a requirement. NEC in 110 uses back reference verbiage, thus if UL verbaige changes it gets reflected in NEC w/o any NEC changes, etc

a readily accessible 10catiol1

is that shorthand for something, i do not know what that is