Working Pro Power using Generator Lockout Kit to Feed the Whole Panel

[Danface]

Switching off the main has no effect on the neutral/ground since those are connected to the city water pipe coming into the house. So if the house is being powered by the truck and the hair dryer falls into the toilet the power going thru the ground would trip the GFCI on the circuit, yes?

BTW, we just upgraded to 200 Amps with a new panel here in Massachusetts which is crazy when it comes to this kind of stuff. We have arc fault breakers for the bedrooms, gfci for any place that a wet dog could shake off and make an outlet damp and whole panel has a surge protector. I realize some parts of the above are moot but an inspector won't OK anything that could be dangerous. I'm not against any of the above.

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[Danface]

I get that but the earth a really big sink so if the main ground is the water pipe how far away would a ground have to be for the truck GFCI not to sense the current from the main neutral. 100 ft, 1000 ft, 20 miles ... there had to a distance at which the grounding rod would be effectively be isolated

 

[Danface]

Stupid planet ... LOL

 

[Maquis]

Why not, wouldn't it provide a path to ground for a ground fault?

The only way a “ground fault” can be cleared is to trip the breaker, which only happens because the neutral and equipment grounding conductor are bonded in the main panel. The fault current must flow back to the panel, connection to dirt does nothing.

 

[Maquis]

The earth is a horrible conductor. Try driving 2 ground rods and measure the resistance between them.

 

[Danface]

Jusr nee ti add water, which in its pure form won't conduct electricity but luckily the earth privides the minerals to make it conductive.

 

[chl]

Switching off the main has no effect on the neutral/ground since those are connected to the city water pipe coming into the house. So if the house is being powered by the truck and the hair dryer falls into the toilet the power going thru the ground would trip the GFCI on the circuit, yes?

BTW, we just upgraded to 200 Amps with a new panel here in Massachusetts which is crazy when it comes to this kind of stuff. We have arc fault breakers for the bedrooms, gfci for any place that a wet dog could shake off and make an outlet damp and whole panel has a surge protector. I realize some parts of the above are moot but an inspector won't OK anything that could be dangerous. I'm not against any of the above.

The hair dryer thing would cause a short and pop a breaker for the circuit it is on.

Wiring a sub-panel in an out-building is equivalent to what you should be doing through the transfer switch, where the "out building sub-panel" is your circuits in the transfer switch being powered in the house by the Lightning. The neutrals should not be grounded in the sub-panel since they are already grounded at the main panel, in your case, the Lightning, but you still want to have a continuous ground between the Lightning and the sub-panel.

The above illustrates this.

The sub-panel circuits have their neutrals going to the neutral terminals on the neutral bar (right side of sub-panel) but the sub-panel neutral bar is NOT ground at the sub-panel.

Unfortunately many licensed electricians may not be familiar with wiring a generator to a dwelling through a transfer switch, and will not do it correctly. But if they understand it as being like wiring a sub-panel, then they should get it.

A lock-out kit might not be deemed code compliant - it depends.
Your locality may allow it under the exception of NEC 702.5, but the issue is whether it is accessible "only" by "qualified persons."

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702.5 Interconnection or Transfer Equipment
(A) General
Interconnection or transfer equipment shall be required for all standby systems subject to the requirements of this article. Equipment shall be suitable for the intended use and shall be listed, designed, and installed so as to prevent the inadvertent interconnection of all sources of supply in any operation of the equipment. [e.g., a Transfer switch]

Exception: Temporary connection of a portable generator without transfer equipment shall be permitted where conditions of maintenance and supervision ensure that only qualified persons service the installation and where the normal supply is physically isolated by a lockable disconnecting means or by disconnection of the normal supply conductors.

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702.11 Portable Generator Grounding
(A) Separately Derived System
Where a portable optional standby source is used as a separately derived system, it shall be grounded to a grounding electrode in accordance with 250.30.

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250.30 (A) Grounded Systems

A separately derived ac system that is grounded shall comply with 250.30(A)(1) through (A)(8). Except as otherwise permitted in this article, a grounded conductor shall not be connected to normally non-current-carrying metal parts of equipment, be connected to equipment grounding conductors, or be reconnected to ground on the load side of the system bonding jumper.

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Translation:

The neutral is a grounded conductor.
The dwelling circuits are the load.
The neutral (grounded conductor) shall not be (also) connected to ground at the load.

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Separately Derived System. An electrical power supply output, other than a service, having no direct connection(s) to circuit conductors of any other electrical source other than those established by grounding and bonding connections. (CMP—5)

 

[Marcelo Zanetti]

There is another path from the neutral to ground via your body if you touch the truck frame. You will feel a shock and if it is working, the GFCI will open. This is not theory this happened to someone whose electrical installer wired a dwelling under construction and disconnected the ground wire from the truck to the house.

Not having the ground from the generator (truck) to the load (house) panel is a no-no according the code if the house is a dwelling.

For $400 and a little time you could do it right using a Generac 6853 Transfer Switch.
The circuits being transfered have their hot and neutrals connected through the transfer switch so they are not bonded (grounded) to the panel ground when being powered by the generator (truck).

As per your drawing, the ground and neutral are bonded in the house panel and the same at the truck receptacle.
I don't see where is the potential for a shock hazard when touching the truck frame, if it is bonded to the ground and the neutral and it shouldn't have any electrical potential to ground since it's bonded at the house panel.

 

[chl]

As per your drawing, the ground and neutral are bonded in the house panel and the same at the truck receptacle.
I don't see where is the potential for a shock hazard when touching the truck frame, if it is bonded to the ground and the neutral and it shouldn't have any electrical potential to ground since it's bonded at the house panel.

Think of it this way.

The neutral is a current carrying conductor carrying return current supply by a hot (phase) conductor.

Some of the current will see a path through the ground if the neutral is grounded at both ends.

That is just the way it is, I am not making it up or theorizing about it.
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Someone with some understanding of split-phase systems might note that if the load is balanced there is no current in the supplied neutral from the Lightning. Yes, but...the chances that the house panel is a balanced load is practically zero. So there will undoubtedly be some current on the neutral conductor.

A balanced load in a house is a ideal goal - it minimized the resistance losses when no net current travels in the neutral - but it is practically unobtainable in a normal household.

 

[chl]

Here is some more info, FYI, which relates to the Lightning as a generator with a GFCI circuit:

Article 230.95 of the National Electrical Code® (NEC®) states:

“Ground-fault protection of equipment shall be provided for solidly grounded wye electric services of more than 150 volts to ground but not exceeding 1000 volts phase-to-phase for each service disconnect rated 1000 amperes or more.”​

A common scheme for detecting ground faults is to use a current transformer(s) to monitor current flow through a circuit’s phase and neutral conductors, as shown in Figure 1. If the sum of current flow is other than zero, a ground fault is indicated. In that event, the ground fault sensing equipment signals a device to open the circuit to mitigate hazards.

[figure 1 omitted see the link if interested. chl]

Controlling Current Pathways

Accurate ground fault sensing requires that the current pathways are known. For instance, if a power system used two grounding electrodes simultaneously without other provisions, some current could return through earth without passing through ground fault sensing equipment, as shown in Figure 2. This would cause sensing equipment to falsely detect faults, causing nuisance tripping and affecting system reliability and availability.

For this reason, a switched neutral can be used in the ATS [automatic transfer switch. chl] to isolate the neutral of the unconnected power source.

For separately derived systems, manufacturers also offer transfer switches that switch the neutral conductor together with the phase conductors. Using a switched neutral isolates the ground conductor of the unconnected power source to avoid ground current pathway problems.

• If the generator is located far from a service entrance, it may be desirable to install a dedicated grounding electrode near the genset to avoid energizing a long conductor during a fault. In addition, a cable cut along the length of the grounding conductor could leave a running generator ungrounded, resulting in unsafe conditions. Designers might consider using a dedicated grounding electrode near the generator to avoid these conditions. Again, a separately derived system may be warranted and a switched neutral transfer switch may be used.
  
  [NOTE: That is why shed or detached garages etc. have their sub-panels grounded with one or more additional ground rods, per the code. chl]

From: https://www.ascopower.com/us/en/res...hen-to-separately-ground-backup-generator.jsp

 

[chl]

That concludes my crash course in electrical wiring of generators.

I hope it has been educational and informative.

It should allow you to double-check that your electrician has done things correctly and that your system will be safe and will pass inspection by being in compliance with electrical codes (the NEC) where applicable.

Please be safe when dealing with any electrical equipment on your own, as the risk of injury or death is possible.

If you are not qualified or confident that you know what you are doing, hire a qualified licensed electrical to install your back-up system.

Never work on live (powered) circuits is a good rule of thumb.

Do not rely solely on the information I have provided in my posts, always confirm things with a qualified electrician. The information I have shared I believe to be true and accurate, however, I take no responsibility for any errors or omissions that may have occurred.

There are inherent risks involved in electrical systems so extreme caution is recommended.

I hereby disclaim any and all liability for any harm resulting from the use or misuse of any information I have provided regarding the issue addressed in this forum post thread.

The information I have shared I believe to be true and accurate, but is provided "as is."

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