Low power on shop electrical circuit.

If an enclosure becomes energized AND it is properly grounded, the return path is through the ground wire, and that will trip the breaker. That ground (EGC) wire has a lot less resistance than you do and the current will use that path. You might get a tingle, though.
 
I think you're halfway there. It's tough to wrap your head around. I used to subscribe to the "path of least resistance" thing.......until I found out that I was really wrong. Check this out...........................

 
From the body of your post............................

View attachment 101354

I don't understand what you're saying.

If the enclosure becomes energized, and you're touching it.........................you become the path to the source......the utility. Voltage flows through your body, attempting to get back to the utility. The only way to make that energized enclosure safe, is to turn off the power that's energizing it. The breaker has to trip. IMHO.

When you look at your wiring, make sure to visualize how a fault is cleared. This is why the green wire is connected to the neutral wire at the disconnect..........................it's a return to source.

If a fault occurs, the only thing that corrects that fault is tripping the breaker. For this, you must have a return to source. A ground rod does nothing to make an enclosure safe when there's a fault........you gotta trip the breaker.

Bonding is a physical connection to the enclosure. The green wire is bonded to the enclosure so that it can take touch voltage from that enclosure,, and return it to source........tripping the breaker in the process.

View attachment 101259
A must read to understand the issue.
I sketched the situation at hand out on a piece of paper.

I agree with what you're saying, in principle.

But also, I looked at the OPs post that said what he found out was wrong and what was done to correct it (post #26 in this thread).

His consulting electrician told him to run another #4 from the main panel to the sub panel to carry the neutral, along with a #10 to carry Earth ground from the main panel to the sub panel. I'm no electrician, but I'm not a fan of that #10... I'm a fan of having the conductor, but not a fan of the size. I like Earth conductors to be at least as large as the current-carrying conductors in any circuit. If a #4 hot wire shorts to the sub-panel, it could carry enough current to burn the #10 Earth conductor open, before opening the breaker feeding the subpanel.

Maybe my thoughts are over and above code here... but, in general... I like Earth conductors to be as large as current-carrying conductors.

If the hot and neutrals to the subpanel are 4AWG... and the protective Earth is 10AWG... I would have another ground rod at the subpanel with a chunky wire to it... just in case...

Other than that...

I'll take the experts' word that neutral shouldn't connect to ground at the subpanel.
 
I sketched the situation at hand out on a piece of paper.

I agree with what you're saying, in principle.

But also, I looked at the OPs post that said what he found out was wrong and what was done to correct it (post #26 in this thread).

His consulting electrician told him to run another #4 from the main panel to the sub panel to carry the neutral, along with a #10 to carry Earth ground from the main panel to the sub panel. I'm no electrician, but I'm not a fan of that #10... I'm a fan of having the conductor, but not a fan of the size. I like Earth conductors to be at least as large as the current-carrying conductors in any circuit. If a #4 hot wire shorts to the sub-panel, it could carry enough current to burn the #10 Earth conductor open, before opening the breaker feeding the subpanel.

Maybe my thoughts are over and above code here... but, in general... I like Earth conductors to be as large as current-carrying conductors.

If the hot and neutrals to the subpanel are 4AWG... and the protective Earth is 10AWG... I would have another ground rod at the subpanel with a chunky wire to it... just in case...

Other than that...

I'll take the experts' word that neutral shouldn't connect to ground at the subpanel.
Let's think of it this way.............................

We can just call it "The Green Wire".

The green wire has to be connected to the enclosure so that it can carry voltage/current back to the power pole if a hot wire contacts the enclosure. The breaker needs a ton of current to work FAST. The green wire allows a TON of current to flow back to the pole. This all happens in a millisecond..........hopefully you're not in contact with the enclosure during that millisecond.

To carry that large amount of current, we need a correctly sized green wire https://conduit.site/tables/table-250.122.php

The correct wire size allows a rush of current to flow from the pole, through the hot wire, through the breaker, through the green wire.........back to the pole. That rush of current trips the breaker.

Forget about anything to do with a ground rod. The ground rod is for lightning(to keep it simple). It has nothing to do with tripping the breaker.

If we don't have the green wire.........where does that hot current go? If you touch the enclosure, it goes through you, through the earth, up the ground rod(in a grounded system), directly to the neutral.........and back to the power company. You're the circuit.

Terminology is the real problem.....................a grounding wire is a grounding wire if it's connected to a ground rod...........but it's also a path back to the pole if it's connected to the neutral at the service disconnect. It serves 2 purposes........................either clear a fault, or dissipate DC current to the Earth from a lightning strike.
 
Let's think of it this way.............................

We can just call it "The Green Wire".

The green wire has to be connected to the enclosure so that it can carry voltage/current back to the power pole if a hot wire contacts the enclosure. The breaker needs a ton of current to work FAST. The green wire allows a TON of current to flow back to the pole. This all happens in a millisecond..........hopefully you're not in contact with the enclosure during that millisecond.

To carry that large amount of current, we need a correctly sized green wire https://conduit.site/tables/table-250.122.php

The correct wire size allows a rush of current to flow from the pole, through the hot wire, through the breaker, through the green wire.........back to the pole. That rush of current trips the breaker.

Forget about anything to do with a ground rod. The ground rod is for lightning(to keep it simple). It has nothing to do with tripping the breaker.

If we don't have the green wire.........where does that hot current go? If you touch the enclosure, it goes through you, through the earth, up the ground rod(in a grounded system), directly to the neutral.........and back to the power company. You're the circuit.

Terminology is the real problem.....................a grounding wire is a grounding wire if it's connected to a ground rod...........but it's also a path back to the pole if it's connected to the neutral at the service disconnect. It serves 2 purposes........................either clear a fault, or dissipate DC current to the Earth from a lightning strike.
THIS IS VERY COOOOOOOOOOOOOOL

 
THIS IS VERY COOOOOOOOOOOOOOL

Ultimately where this is going is an argument against my assertion that I don't need a GFCI in a non wet environment. These traditional breakers will clear a hard ground fault, or short circuit..............but they won't protect you if you grab a hot wire, or stick a screwdriver in a receptacle. The GFCI will.
 
I sketched the situation at hand out on a piece of paper.

I agree with what you're saying, in principle.

But also, I looked at the OPs post that said what he found out was wrong and what was done to correct it (post #26 in this thread).

His consulting electrician told him to run another #4 from the main panel to the sub panel to carry the neutral, along with a #10 to carry Earth ground from the main panel to the sub panel. I'm no electrician, but I'm not a fan of that #10... I'm a fan of having the conductor, but not a fan of the size. I like Earth conductors to be at least as large as the current-carrying conductors in any circuit. If a #4 hot wire shorts to the sub-panel, it could carry enough current to burn the #10 Earth conductor open, before opening the breaker feeding the subpanel.

Maybe my thoughts are over and above code here... but, in general... I like Earth conductors to be as large as current-carrying conductors.

If the hot and neutrals to the subpanel are 4AWG... and the protective Earth is 10AWG... I would have another ground rod at the subpanel with a chunky wire to it... just in case...

Other than that...

I'll take the experts' word that neutral shouldn't connect to ground at the subpanel.
My immediate reply to you was a bit off, and didn't address what you actually said.

Yeah..............it makes sense to have the equipment ground at about the same size as the hot wire. But.........what I'm wondering is........how much current does it take to flip the breaker. If a 10ga wire will carry the required current, I guess it's properly sized.

In the link I put up, the 10ga will handle a 60amp breaker. Sounds a bit small, but the NEC says it will(shrug)
 
My immediate reply to you was a bit off, and didn't address what you actually said.

Yeah..............it makes sense to have the equipment ground at about the same size as the hot wire. But.........what I'm wondering is........how much current does it take to flip the breaker. If a 10ga wire will carry the required current, I guess it's properly sized.

In the link I put up, the 10ga will handle a 60amp breaker. Sounds a bit small, but the NEC says it will(shrug)
Probably a difference in requirements. The #4 wire will provide minimum drop to a load, while being serviced by a 60A breaker. The #10 will carry enough current to trip it... as long as the breaker trips. If the breaker fails to trip; then the #10 will fuse open. But that is an extremely rare circumstance.

I used to work in electrical safety design of equipment... not power distribution per se... as in, AC wiring inside the chassis of a product. In that little microcosm the UL rules essentially require that the ground conductors and ground bonds (ground studs, etc) be sized to carry just as much, or more, current as the "hot" L1 and L2 (Line 1 and Line 2...because when you design for universal power for worldwide products a "neutral" isn't guaranteed).

I smell what you're stepping in. I guess I spent quite a while stepping in something slightly different.
 
FYI Just to clear snd wrap up a few things above and some terminology I was taught by nec experts and board members and nec verbage when I practiced but beware nec may have since changed so don’t take my word consult the nec

A Grounding Electrode Conductor is the often no 4 bare copper wire from neutral to the grounding electrode system such as driven ground rods etc

An Equipment Grounding Conductor, (EGC) often just called ground by some, may be the bare or insulated green wire that may connect to non normal current carrying conductive appliance enclosures or junction boxes or panel tubs etc etc Back to the Equipment Gtound Buss in the panel

Purpose of the EGC is to carry only fault current providing a fault current return path so the breeker can trip and clear the fault

EGC might be smaller than current carrying conductors in certain cases all subject to nec as they only need to carry enough fault current for a certain time to allow the breaker to trip. Often and typical they are the same size as conductors you have to carefully consult the nec before going here lol

There is to be only one NG Bond typically at the first means if disconnect

Earthing or earth grounding the neutral is for hv surges spikes and lightning protection and providing a common low voltage reference for the grid

Note this is not exact or perfect it’s impossible to explain entire nec chapters here. It’s only my best recollection no warranty consult the nec not what’s posted here but I try my best to help best I can

John T
 
When you look at your wiring, make sure to visualize how a fault is cleared. This is why the green wire is connected to the neutral wire at the disconnect..........................it's a return to source.

If a fault occurs, the only thing that corrects that fault is tripping the breaker. For this, you must have a return to source. A ground rod does nothing to make an enclosure safe when there's a fault........you gotta trip the breaker.

Bonding is a physical connection to the enclosure. The green wire is bonded to the enclosure so that it can take touch voltage from that enclosure,, and return it to source........tripping the breaker in the process.

View attachment 101259
A must read to understand the issue.
Neutral bar up upon isolating blocks
 
FYI Just to clear snd wrap up a few things above and some terminology I was taught by nec experts and board members and nec verbage when I practiced but beware nec may have since changed so don’t take my word consult the nec

A Grounding Electrode Conductor is the often no 4 bare copper wire from neutral to the grounding electrode system such as driven ground rods etc

An Equipment Grounding Conductor, (EGC) often just called ground by some, may be the bare or insulated green wire that may connect to non normal current carrying conductive appliance enclosures or junction boxes or panel tubs etc etc Back to the Equipment Gtound Buss in the panel

Purpose of the EGC is to carry only fault current providing a fault current return path so the breeker can trip and clear the fault

EGC might be smaller than current carrying conductors in certain cases all subject to nec as they only need to carry enough fault current for a certain time to allow the breaker to trip. Often and typical they are the same size as conductors you have to carefully consult the nec before going here lol

There is to be only one NG Bond typically at the first means if disconnect

Earthing or earth grounding the neutral is for hv surges spikes and lightning protection and providing a common low voltage reference for the grid

Note this is not exact or perfect it’s impossible to explain entire nec chapters here. It’s only my best recollection no warranty consult the nec not what’s posted here but I try my best to help best I can

John T

Now I need to check how our farm is wired, with respect to the neutral and the "first means of disconnect."

We have a meter out by the road on what I call a "placard"... a sheet of plywood between a couple of 4x4 posts... all painted white (which doesn't really matter)...

Anyway, the meter connects to a panel on the placard. Inside the panel is a breaker for the house and a breaker for the barn; which could be the "first means of disconnect" at the meter. From the placard, underground wiring carries power to the house, which has a typical entrance panel with a typical main breaker... and to the barn, which has a typical entrance panel with a typical main breaker. Both panels have ground rods. Both panels have ground bus bars. Both panels have neutral bus bars. Both panels have a ground to neutral connection.

I won't even go into the fact that the barn has another subpanel at the other end; which used to be used for the barn cleaner, and lighting at that end of the barn.

I assume that it was all put in by an electrician... but you never know

P.S. I'm not going to change anything. I just want to compare how the existing wiring compares to your paragraphs above. And I hold you harmless as to being a source of gospel wrt NEC.
 
Now I need to check how our farm is wired, with respect to the neutral and the "first means of disconnect."

We have a meter out by the road on what I call a "placard"... a sheet of plywood between a couple of 4x4 posts... all painted white (which doesn't really matter)...

Anyway, the meter connects to a panel on the placard. Inside the panel is a breaker for the house and a breaker for the barn; which could be the "first means of disconnect" at the meter. From the placard, underground wiring carries power to the house, which has a typical entrance panel with a typical main breaker... and to the barn, which has a typical entrance panel with a typical main breaker. Both panels have ground rods. Both panels have ground bus bars. Both panels have neutral bus bars. Both panels have the a ground to neutral connection.

I won't even go into the fact that the barn has another subpanel at the other end; which used to be used for the barn cleaner, and lighting at that end of the barn.

I assume that it was all put in by an electrician... but you never know

P.S. I'm not going to change anything. I just want to compare how the existing wiring compares to your paragraphs above. And I hold you harmless as to being a source of gospel wrt NEC.
Back in the day that was how things were done and you are grandfathered in I believe. Probably have ground rods in all locations.
 
Back in the day that was how things were done and you are grandfathered in I believe. Probably have ground rods in all locations.
In practice, it just provides me a little food for thought, mostly with respect to lightning. We have a couple of electric fence controllers, they can be literal "lightning rods," bringing lightning surges into your building's power, even if you have those surge arrestors on the wire.

Where ground rods are and how neutrals are done may affect my thinking about where to plug in the electric fence.
 
Now I need to check how our farm is wired, with respect to the neutral and the "first means of disconnect."

We have a meter out by the road on what I call a "placard"... a sheet of plywood between a couple of 4x4 posts... all painted white (which doesn't really matter)...

Anyway, the meter connects to a panel on the placard. Inside the panel is a breaker for the house and a breaker for the barn; which could be the "first means of disconnect" at the meter. From the placard, underground wiring carries power to the house, which has a typical entrance panel with a typical main breaker... and to the barn, which has a typical entrance panel with a typical main breaker. Both panels have ground rods. Both panels have ground bus bars. Both panels have neutral bus bars. Both panels have a ground to neutral connection.

I won't even go into the fact that the barn has another subpanel at the other end; which used to be used for the barn cleaner, and lighting at that end of the barn.

I assume that it was all put in by an electrician... but you never know

P.S. I'm not going to change anything. I just want to compare how the existing wiring compares to your paragraphs above. And I hold you harmless as to being a source of gospel wrt NEC.
Will wow what an excellent question thanks for posting it here’s my professional opinion:

1. I will not tell you to change it. Different areas have different rules some never adopt nec some have their own rules

2 in the areas I practiced at the time it would have been wired different with the onlyyyy ng bond at that first disconnect and 4 wires carried out with later panels configured as sub panels with nooooo ng rebonding similar to how mobile home pedestals are now wired with subs at trailers or RVs

3 when you re bond after your placard that bare EGC is in parallel with the neutral and becomes a hot live curtent carrier and is connected to metal frames etc which you can come in contact with

4 so it works it’s grandfathered in plus it was done where you live so I’m not telling you to change it. If the rules change or you upgrade you might be required to chenge things iffff they adopt current nec that is

5 there’s a good reason for only one ng bond in todays code it would take me time to explain it so leave as is unless and until you upgrade or locals tell you to change and upgrade

PS. It remains a FACT that as it’s now wired with the lster downstream re bond of n and g the EGC and all metal cases and parts are hot live current carriers and I’m not a fan of putting my body into a parallel path with live current carriers . That’s how Mike holt explained the new rules in his seminars

PS I don’t mean to cause any alarm rules are different in different places at different times

PS I may be wrong this was my understanding g of the nec when and where I practiced I’m only trying to help
John T.
 
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Will wow what an excellent question thanks for posting it here’s my professional opinion:

1. I will not tell you to change it. Different areas have different rules some never adopt nec some have their own rules

2 in the areas I practiced at the time it would have been wired different with the onlyyyy ng bond at that first disconnect and 4 wires carried out with later panels configured as sub panels with nooooo ng rebonding similar to how mobile home pedestals are now wired with subs at trailers or RVs

3 when you re bond after your placard that bare EGC is in parallel with the neutral and becomes a hot live curtent carrier and is connected to metal frames etc which you can come in contact with

4 so it works it’s grandfathered in plus it was done where you live so I’m not telling you to change it. If the rules change or you upgrade you might be required to chenge things iffff they adopt current nec that is

5 there’s a good reason for only one ng bond in todays code it would take me time to explain it so leave as is unless and until you upgrade or locals tell you to change and upgrade

John T.
Your #3 sounds like a good enough reason to me.
 
Your #3 sounds like a good enough reason to me.
And the fact is no 3 is true and reason for the code as it now is but again it’s not for me to decide for anyone else it’s working and maybe ok when and where it was installed. To each their own do as anyone pleases lol

JT
 
Now I need to check how our farm is wired, with respect to the neutral and the "first means of disconnect."

We have a meter out by the road on what I call a "placard"... a sheet of plywood between a couple of 4x4 posts... all painted white (which doesn't really matter)...

Anyway, the meter connects to a panel on the placard. Inside the panel is a breaker for the house and a breaker for the barn; which could be the "first means of disconnect" at the meter. From the placard, underground wiring carries power to the house, which has a typical entrance panel with a typical main breaker... and to the barn, which has a typical entrance panel with a typical main breaker. Both panels have ground rods. Both panels have ground bus bars. Both panels have neutral bus bars. Both panels have a ground to neutral connection.

I won't even go into the fact that the barn has another subpanel at the other end; which used to be used for the barn cleaner, and lighting at that end of the barn.

I assume that it was all put in by an electrician... but you never know

P.S. I'm not going to change anything. I just want to compare how the existing wiring compares to your paragraphs above. And I hold you harmless as to being a source of gospel wrt NEC.
Great video posted above by farmersamm. Highly recommend that everyone interested in wiring watch it. done by one of the recognized expertsin the field. It covers grounding, bonding and safety. Nuff said.
 
PS to Wills great question above

RE my para 3. If a change were required by the utility or any local authority and if it was necessary to upgrade, all required to update to only having a single ng bond would be to un bond at those downstream panels making them true subs with separate insulated and isolated n and g busses. Easy peasey but dont do anything I say consult the nec or local professionals don’t risk the farm in anything posted here lay or professional me included !!!!

JT
 
PS to Wills great question above

RE my para 3. If a change were required by the utility or any local authority and if it was necessary to upgrade, all required to update to only having a single ng bond would be to un bond at those downstream panels making them true subs with separate insulated and isolated n and g busses. Easy peasey but dont do anything I say consult the nec or local professionals don’t risk the farm in anything posted here lay or professional me included !!!!

JT
Definitely...first do no harm.

I'm not changing this. There are only three wires from the placard to the barn and three wires from the placard to the house... meaning... neutral and two phases.... I'm not floating any neutrals in the house or barn from their respective protective earth conductors (green wires in the building wiring) without the fourth wire from the placard.
 
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Great video posted above by farmersamm. Highly recommend that everyone interested in wiring watch it. done by one of the recognized expertsin the field. It covers grounding, bonding and safety. Nuff said.
X2. Of the nec seminars I attended it’s my opinion books or advice by Mike holt are the best but it’s hard to put in a book or explain here all the details of grounding and bonding which can take years to understand grrrr lol

Nice chatting

JT
 

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