- Location
- Illinois
- Occupation
- retired electrician
How can the utilization equipment function if there is no outlet???????????
2023 NATIONAL ELECTRIC CODE - Section 210.8(F)
- Thread starter mtnelect
- Start date
- Status
If they could somehow design Ground Fault Protection for equipment that would magically activate "prior to human contact" we wouldn't need GFI protection for personnel at all.
JAP>
Tulsa Electrician
Senior Member
- Location
- Tulsa
- Occupation
- Electrician
kwired
Electron manager
- Location
- NE Nebraska
Probably 99%+ of GFCI or GFPE trips do occur "prior to human contact"Is that called a GFCI
Is that called a GFCI
No, because it is impossible to pinpoint when a human will be in contact with a piece of equipment at the time of the fault.
JAP>
Probably, but, if a piece of equipment faults on a GFPE circuit with a human in contact with it, it's still too much.
JAP>
kwired
Electron manager
- Location
- NE Nebraska
I know. Will add that GFCI does not 100% prevent shocks either. Most the time it does simply because it does trip before human contact occurs. But if human contact is what completes the circuit to cause a ~5 mA ground fault - that person will very likely feel it and it can be pretty good jolt.
Want to try it out- just place yourself in series with EGC somehow and press the test button on one those GFCI testers, it will wake you up.
I'm not that guy that sat in the bath tub when GFCI's first came out to prove they worked.
I don't trust other people's work as much as you do.
JAP>
kwired
Electron manager
- Location
- NE Nebraska
My point was 5mA is more of a shock than some realize, as well as pointing out majority of the time the protection device kicks in before there ever is a shock incident.
I know of a former inspector that once told the story of checking a GFCI in an outdoor location with metal weatherproof cover. Tester indicated no ground, not thinking about it much he pressed the GFCI test button on his tester and because he was contacting the metal cover.....he got a pretty good jolt out of it. He said lesson learned there. I haven't done that myself, but probably will think about it after that story should similar situation come up. I have been between ground and ungrounded conductor before via a low impedance meter - can tell you it wakes you up as well.
An electric fence also.
I know, I grab onto them every now and then for no other reason than to see what it's packin.
JAP>
Bill Snyder
NEC expert
- Location
- Denver, Co
- Occupation
- Electrical Foreman
Bill Snyder
NEC expert
- Location
- Denver, Co
- Occupation
- Electrical Foreman
Why would CMP-2 write a definition individual branch circuit and forget to mention it always connects to an outlet and why would 210.8(D) say utilization equipment is sometimes hardwired to outlets instead of always hardwired to outlets?
wwhitney
Senior Member
- Location
- Berkeley, CA
- Occupation
- Retired
Because that's obvious from the definition of outlet?
What version of 210.8(D) are you reading? I don't see any language like that in the 2017, 2020, or 2023 NECs.
Cheers, Wayne
Tulsa Electrician
Senior Member
- Location
- Tulsa
- Occupation
- Electrician
Great point
Another great, Point. I would think In your case the metal cover was energized from issue. There was no way for the fault to be detected and open until a path was provided for the measured current flow to be detected by the GFCI and open.
Difference, an EGC .
This one reason why I would think NEC would never allow any thing other The GFCI for personal.
Most see it all the time poor EGC connections and terminations.
Case in point, we have a j man at work who thinks grounding is a myth. His logic is plain nuts. I tell everyone don't listen to him and his installations reflect his poor choices. In this case the NEC would provide protection for his bad choice.
My way, GFCI trips before touch.
His way, touch to trip GFCI. He applies bird on A wire. He would state I'm not grounded so I would not get hurt. No fault path.
I argue there would be no need to be bird on the wire if wires per NEC and an proper sized and installed EGC is present.
In this cases stated above both would apply as code compliant installations.
HVAC equipment requires a EGC no exception.
I wish it required. A wire type no exception.
Case in point. I have seen and worked on many older replacement HVAC units with a whip that had no wire type EGC. Now we have potential a shock hazords. Even with a GFCI based on this discussion. It becomes a touch issue.
So let's look at what the ac units set on as an example.
They used to set on a concrete pad. This pad was poured on the earth.
GFCI could have potential to trip.
Now, we have poly pads and snow shoes. A snow shoe is a set of plastic feet that set it up off the ground. Now required in most areas. With No EGC touch potential to trip.
Ac units sitting on roof where a rubber membrane in is used. You get the idea.
In this application a disconnect is usually screwed to the unit. This EGC is attached to disconnect. No EGC is ran into unit. The two or three hot ran thru case nipple and in some case no nipple at all. The screws were simple sheet metal screws. Very poor bonding.
A replacement GFCI in a Two wire circuit is allowed.
What should have been done if a two wire circuit with GFCI was the case a metal cover is a violation as no way to bond it. A plastic cover should have been used.
However this would not prevent the ground prong touch potential.
Also I would bet he was a three prong push button that uses ground shunt. I have seen many inspectors have the GFCI tester set to 5 and just plug it in. What they should have done was plug in then move dial to test. They just don't have time so I get it.
Could this be one reason why they have self test now. It solves a lot of issues.
Case in point job I'm on now. Two electrical contractors. The other did a bathroom/ office remodel.
Insp came and gave final.
Plumber ask my help to look at water fountain. I ask him why off task. He stated the plumber said the water fountain don't work. I ask him to return to his duties as this is not in our scope. The self test detected reversed line load. So it would not work. This device most likely at some point saved a life
I hear all the time it passed insp. Most of the time I just chinge.
I have a rule the only time a metal cover is used is in a situation usually commerical and proper bonding is applied. I have caught many not using the green bond wire. All which received a reprimand and further training.
Getting, ok long winded. Just wanted to touch on the points being made. I hope the HVAC mfg will get on board with testing and make the to a new standard.
Last note. Look at most evaporated motors they have a ground wire to frame and use a sheet metal screw.
We are required to have two threads aka 32. Based on standard thickness for ensured ground/ bonding. What gauge is that sheet metal. So why not run that green wire all the way back to a ground buss inside the unit where I EGC is attached. Now leak potential will be picked up by the GFCI before a personal contact with the top of the unit where the motor sets and a properly grounded source of potential.
In this case I see it as a equipment issue. Any grounding is not a myth.
Hard choice have to be made by both sides, Ele and HVAC.
Joke; in this post I installed Energizer battery. It just kept going and going and going.
Summarize:
Both had great points.
kwired
Electron manager
- Location
- NE Nebraska
The cover was energized by the GFCI testing device introducing a small load from ungrounded to EGC terminal of the receptacle which in normal installation is bonded to the device yoke via mounting screws. The issue in my story was that for whatever reason there was no EGC back to the system bonding jumper, or any other path for that matter so it left everything connected to the device yoke at 120 volts to "ground" Most the testers used have no setting they are just a receptacle polarity testing device with a single resistance push to test for testing GFCI function. Lesson learned was if the tester indicates no ground, think about it before pressing the test button when using such tester.Great point
Another great, Point. I would think In your case the metal cover was energized from issue. There was no way for the fault to be detected and open until a path was provided for the measured current flow to be detected by the GFCI and open.
Difference, an EGC .
This one reason why I would think NEC would never allow any thing other The GFCI for personal.
Most see it all the time poor EGC connections and terminations.
Case in point, we have a j man at work who thinks grounding is a myth. His logic is plain nuts. I tell everyone don't listen to him and his installations reflect his poor choices. In this case the NEC would provide protection for his bad choice.
My way, GFCI trips before touch.
His way, touch to trip GFCI. He applies bird on A wire. He would state I'm not grounded so I would not get hurt. No fault path.
I argue there would be no need to be bird on the wire if wires per NEC and an proper sized and installed EGC is present.
In this cases stated above both would apply as code compliant installations.
HVAC equipment requires a EGC no exception.
I wish it required. A wire type no exception.
Case in point. I have seen and worked on many older replacement HVAC units with a whip that had no wire type EGC. Now we have potential a shock hazords. Even with a GFCI based on this discussion. It becomes a touch issue.
So let's look at what the ac units set on as an example.
They used to set on a concrete pad. This pad was poured on the earth.
GFCI could have potential to trip.
Now, we have poly pads and snow shoes. A snow shoe is a set of plastic feet that set it up off the ground. Now required in most areas. With No EGC touch potential to trip.
Ac units sitting on roof where a rubber membrane in is used. You get the idea.
In this application a disconnect is usually screwed to the unit. This EGC is attached to disconnect. No EGC is ran into unit. The two or three hot ran thru case nipple and in some case no nipple at all. The screws were simple sheet metal screws. Very poor bonding.
A replacement GFCI in a Two wire circuit is allowed.
What should have been done if a two wire circuit with GFCI was the case a metal cover is a violation as no way to bond it. A plastic cover should have been used.
However this would not prevent the ground prong touch potential.
Also I would bet he was a three prong push button that uses ground shunt. I have seen many inspectors have the GFCI tester set to 5 and just plug it in. What they should have done was plug in then move dial to test. They just don't have time so I get it.
Could this be one reason why they have self test now. It solves a lot of issues.
Case in point job I'm on now. Two electrical contractors. The other did a bathroom/ office remodel.
Insp came and gave final.
Plumber ask my help to look at water fountain. I ask him why off task. He stated the plumber said the water fountain don't work. I ask him to return to his duties as this is not in our scope. The self test detected reversed line load. So it would not work. This device most likely at some point saved a life
I hear all the time it passed insp. Most of the time I just chinge.
I have a rule the only time a metal cover is used is in a situation usually commerical and proper bonding is applied. I have caught many not using the green bond wire. All which received a reprimand and further training.
Getting, ok long winded. Just wanted to touch on the points being made. I hope the HVAC mfg will get on board with testing and make the to a new standard.
Last note. Look at most evaporated motors they have a ground wire to frame and use a sheet metal screw.
We are required to have two threads aka 32. Based on standard thickness for ensured ground/ bonding. What gauge is that sheet metal. So why not run that green wire all the way back to a ground buss inside the unit where I EGC is attached. Now leak potential will be picked up by the GFCI before a personal contact with the top of the unit where the motor sets and a properly grounded source of potential.
In this case I see it as a equipment issue. Any grounding is not a myth.
Hard choice have to be made by both sides, Ele and HVAC.
Joke; in this post I installed Energizer battery. It just kept going and going and going.
Summarize:
Both had great points.
Self test feature on GFCI receptacles is not a replacement for the test button on the GFCI, and one should still test them even though we know they probably don't get tested all that often. The self test feature doesn't introduce or simulate an actual fault condition, it just runs a predetermined function test of the logic chip in the device to prove the electronics are still alive. Self test function isn't what locks it out if line and load are reversed, they actually had that feature before the self test feature. I can tell you a P&S GFCI will still function with line and load reversed, but it won't reset once it has tripped. They are shipped in tripped condition therefore first time energizing it won't reset if you have it wired backwards. And the way it is designed both the line and load side terminals are disconnected from the receptacle face when it is tripped. It has to sense voltage on the line terminals before it will reset.
A condenser or evaporator motor being bonded via a sheet metal screw- that is not a NEC issue it has passed listing requirements. And for the most part the outer frame is what needs bonded for best touch protection from anyone that happens to touch the unit. I have encountered laundry appliances with variable speed motors that don't play well with GFCI's. To make them play better they actually do isolate the motor frame from the EGC, but some do have a bonding conductor run to a switch that closes to the EGC if the access cover is removed, I imagine this is to protect a service person or anyone that happens to take the cover off. My first learning about this arrangement involved a customer that had a washer that did work then suddenly started tripping the GFCI it was plugged in to. It would fill just fine but then as soon as it started to turn the tub, GFCI would trip. I eventually found this "ground switch" had broken mounting clip and therefore wasn't being "held open" anymore. Simple manually holding the switch allowed the machine to run without tripping anymore. Note I did get a proper replacement switch for it, though I could have just left it in a condition where it would never close and they would never known any difference.
Tulsa Electrician
Senior Member
- Location
- Tulsa
- Occupation
- Electrician
Great information, thank you.
Pulled this out of soares book.
Just to add to discussion.
For other reading I would recommend reading through 250.4
Good refresher.
Forgot to add a section from book.
I like the way it touches on two pieces of equipment and touch between them.
Pulled this out of soares book.
Just to add to discussion.
For other reading I would recommend reading through 250.4
Good refresher.
Forgot to add a section from book.
I like the way it touches on two pieces of equipment and touch between them.
Attachments
SSDriver
Senior Member
- Location
- California
- Occupation
- Electrician
So they based GFCi protection needed on HVAC on a case where there was no EGC and someone died. Now what makes you think that a Hack who didn't install an EGC (that would have cleared the breaker) is going to install a GFCI that costs more.
That's like saying. We have a case where someone died in a car crash. He wasn't wearing his seat belt and it didn't have a air bag. New law. All drivers need helmets .
That's like saying. We have a case where someone died in a car crash. He wasn't wearing his seat belt and it didn't have a air bag. New law. All drivers need helmets .
kwired
Electron manager
- Location
- NE Nebraska
The driving force of the new GFCI requirements the past few code cycles has been the rather uncommon situations that come up and often because of mis-use or poor installs causing an electrocution. Or from recollection the reason they added up to 100 amps receptacles in some cases was nothing more than "because we have that ability" so to speak if you look into the draft reports and such.
In 80's and 90's at least most the GFCI changes had more justification such as statistics beyond a single incident to support the change. Most those requirements then involved 5-15 and 5-20 cord/plugs that are well known to often have a broken EGC pin on the plugs or extension cords. How often has anyone seen a missing EGC pin on a plug that isn't a 5-15 or 5-20? It is pretty rare so the EGC isn't so likely to be compromised in those cases.
Swimming pool applications was about the only place it made sense to require GFCI protection on something hard wired.
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