Possible Interlock solution for 7.2kw PPO for whole house setup? (looking for insights/confirmation)

[CAG61]

I have been following this through the many threads and have come to think the code is not well thought out.

For example at my house the power comes in at my pump house, bonded and earth ground. Next it feeds the house main panel 100 feet. Grounded again and bounded. The barn, also fed from the pump house, 50 feet, not grounded to earth. All passed inspection.

I have an interlock on the pump house and the generator powers everything just fine. But, I read that PB won't power the house. It seems like the PB is wired wrong, yet it powers my RV as does my generator.

Am I correct that adding a GFCI on the 30amp plug like the PB has but my generator does not is the problem/issue?

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[dafish]

Could that be done in a way that would still allow a whole home setup or would I then be back to picking specific circuits? If i do a transfer switch to backfeed into the whole panel, would I then be tied into using a bonded neutral generator due to the initial considerations to make the truck work assuming I could go the interlock method?

When I get to this I'll be backfeeding several paralleled inverters via 14-50's connected to my home panel. I happen to support Hammans "dogbone" philosophy, so I will not be connecting the ground leads from the genset.

This is controversial, and some, Hullguy as an example, are firmly against same. Fine, I'm not going to say he's wrong. At the same time the controversy tends to follow "it's not defined as acceptable within code, don't call me when you burn down your house". That said, I've not seen anything electrically problematic with it. Prudence would be advisable of course. Personally I connect gensets before starting them, and the switch loads on. I also power them down before unhooking them. Both avoid a variety of risk points.

Done with prudence I believe this is perfectly safe.

 

[techmonkie]

Think about what the Powerboosts electrical generation system is called, “Bonded Neutral”. This means that the ground and neutral are bonded at the truck already. What you are suggesting is a second bonding of the neutral and ground. The ground path is already there.
This also does not remove the existing ground neutral bond at the house causing the Powerboost to see 2 bonds in the circuit and trip out on ground fault. You would be adding a third ground neutral bond

So I have some follow up questi9ns about this but will need a little time to articulate them properly. I'll have to type it up tomorrow.

 

[AndreB]

Could you provide an example of what this would look like? Can you recommend a product that would fit the intended way you're recommending I think about solving the need?

Thanks

Hello, just wanted to share my solution…

I solved all of the bounded/not bounded neutral lead by using a sub panel and carrying over to the sub pannel all of the emergency circuits that I wanted to be switched from the utility company to my generator. The same solution can also be applied to using a Powerboost Ford F 150 as a generator provider.

The sub pannel that I used is a "Generator panel, QO, 1 phase, 18 spaces, 36 circuits, 30A main breaker, PoN, NEMA1, cover with door, UL. Part number: QOGP3P3036P, from Schneider Electric". Can be used with either neutral bounded and non neutral bounded "with a ground modification" generator.

https://www.se.com/ca/en/product/QO...0a-main-breaker-pon-nema1-cover-with-door-ul/

 

[CAG61]

Hello, just wanted to share my solution…

I solved all of the bounded/not bounded neutral lead by using a sub panel and carrying over to the sub pannel all of the emergency circuits that I wanted to be switched from the utility company to my generator. The same solution can also be applied to using a Powerboost Ford F 150 as a generator provider.

The sub pannel that I used is a "Generator panel, QO, 1 phase, 18 spaces, 36 circuits, 30A main breaker, PoN, NEMA1, cover with door, UL. Part number: QOGP3P3036P, from Schneider Electric". Can be used with either neutral bounded and non neutral bounded "with a ground modification" generator.

https://www.se.com/ca/en/product/QO...0a-main-breaker-pon-nema1-cover-with-door-ul/

I am hoping someone can explain this better for me.
1 - Power Company does not implement GFI
2 - Power Company does not connect neutral and ground? or do they at the pole
3 - Code requires me to join ground and neutral in the box when using Grid Power, actually at each panel for me as they are too far apart to use the other panel's ground.

Now if I put in a generator, instead of using the grid, the rules change. and it is suddenly way more dangerous using a generator than a grid power source. is this really true or this is a cause of yeah the grid is unsafe but it costs too much to fix it.

If I understand the solar guy, a grid tie connection will work just fine for him and it I can disconnect the grid it can even power the house, no change in neutral/ground.

Or I can use a portable generator and it works fine... just not the Powerboost?

 

[Gros Ventre]

I am hoping someone can explain this better for me.
1 - Power Company does not implement GFI
2 - Power Company does not connect neutral and ground? or do they at the pole
3 - Code requires me to join ground and neutral in the box when using Grid Power, actually at each panel for me as they are too far apart to use the other panel's ground.

Now if I put in a generator, instead of using the grid, the rules change. and it is suddenly way more dangerous using a generator than a grid power source. is this really true or this is a cause of yeah the grid is unsafe but it costs too much to fix it.

If I understand the solar guy, a grid tie connection will work just fine for him and it I can disconnect the grid it can even power the house, no change in neutral/ground.

Or I can use a portable generator and it works fine... just not the Powerboost?

The NEC requires the Neutral-Ground bond to be in a single place. What the electric company does external to your house does not need to be addressed. The electric company presumes you'll have the single bond in your house. Usually this occurs at a Green Screw in the main panel, commonly in the upper right side and behind the cover panel. In my case my electric company requires that bond to be done out at the meter box. What is important is that there be only one bonding point.

 

[HammaMan]

I am hoping someone can explain this better for me.
1 - Power Company does not implement GFI
2 - Power Company does not connect neutral and ground? or do they at the pole
3 - Code requires me to join ground and neutral in the box when using Grid Power, actually at each panel for me as they are too far apart to use the other panel's ground.

Now if I put in a generator, instead of using the grid, the rules change. and it is suddenly way more dangerous using a generator than a grid power source. is this really true or this is a cause of yeah the grid is unsafe but it costs too much to fix it.

If I understand the solar guy, a grid tie connection will work just fine for him and it I can disconnect the grid it can even power the house, no change in neutral/ground.

Or I can use a portable generator and it works fine... just not the Powerboost?

The utility feeds you L1, L2, and N, it does not provide a ground. The utility grounds the neutral at every transformer and every power pole. Inspect a power pole and you'll see a 4ga bare copper wire stapled to it running up the pole (very well camouflaged due to the creosote). It runs to the bottom of the pole and is coiled around its bottom. The neutral is often the top wire to catch smaller branches while also hoping to divert lightning into the ground to reduce the chances of lightning damage. Even still I've seen lightning vaporize every wire attached to a transformer while also welding its core (70kva). The old head thought it was a joke and we'd removed all of its conductors leaving a bare transformer on the pole.

The dogbone with discontinuous ground does the same thing providing L1/L2/N. Portable generators are N/G bonded and do not contain a GFI on the 30a circuit. When you connect them to a home you're double bonded. This is how probably close to 99% of people feed their home w/ portable generators, despite not being code compliant. From a safety standpoint, floating the ground via dogbone on the PB w/ GFI is safer than a double bonded neutral generator interconnect configuration.

 

[Hullguy]

”From a safety standpoint, floating the ground via dogbone on the PB w/ GFI is safer than a double bonded neutral generator interconnect configuration.”
I disagree whole heartedly! It’s not National Electrical Code compliant in any instance! By using this dogbone with the ground cut off you are not following the dictates of many parts of Article 250, and Article 100. It is not a safe installation because you no longer have a grounding source by cutting the ground off of the plug.
The reason why 99% of people with portable generators can plug into an existing electrical system is because the generators are floating grounds and the existing ground system is connected to the generator.
The PowerBoost has the neutral bonded at the vehicle. It is a totally different type of generator than most! It requires a neutral switching transfer switch to satisfy National Electrical Code standards on grounding at only one point in your electrical system.
Work arounds and cheaters are what they are, work arounds and cheaters and are unsafe.

 

[Hullguy]

Hello, just wanted to share my solution…

I solved all of the bounded/not bounded neutral lead by using a sub panel and carrying over to the sub pannel all of the emergency circuits that I wanted to be switched from the utility company to my generator. The same solution can also be applied to using a Powerboost Ford F 150 as a generator provider.

The sub pannel that I used is a "Generator panel, QO, 1 phase, 18 spaces, 36 circuits, 30A main breaker, PoN, NEMA1, cover with door, UL. Part number: QOGP3P3036P, from Schneider Electric". Can be used with either neutral bounded and non neutral bounded "with a ground modification" generator.

https://www.se.com/ca/en/product/QO...0a-main-breaker-pon-nema1-cover-with-door-ul/

This is a Neutral Switching Transfer switch which is NEC compliant and the proper way to use the Powerboost as an electrical source.

 

[HammaMan]

”From a safety standpoint, floating the ground via dogbone on the PB w/ GFI is safer than a double bonded neutral generator interconnect configuration.”
I disagree whole heartedly! It’s not National Electrical Code compliant in any instance! By using this dogbone with the ground cut off you are not following the dictates of many parts of Article 250, and Article 100. It is not a safe installation because you no longer have a grounding source by cutting the ground off of the plug.
The reason why 99% of people with portable generators can plug into an existing electrical system is because the generators are floating grounds and the existing ground system is connected to the generator.
The PowerBoost has the neutral bonded at the vehicle. It is a totally different type of generator than most! It requires a neutral switching transfer switch to satisfy National Electrical Code standards on grounding at only one point in your electrical system.
Work arounds and cheaters are what they are, work arounds and cheaters and are unsafe.

Portable generators are NG bonded else the grounding conductor is useless for anything plugged into it requiring a ground. This is a requirement of portable generators. Furthermore when connected to a structure a portable generator must be connected to earth when connected to a structure with switched neutral. This is true for pretty much every inverter out there as well unless it's made specifically for grid-tie and will be labeled as such. Otherwise the system is double bonded. Because the frame is serving as the 'ground', the frame itself must be earthed.

Code isn't the magic shield you believe it to be. 28,000+ code compliant structures catch fire each year. Furthermore as previously discussed it's a catch-all and doesn't address situations such as this where the 'generator' has additional protections built in to prevent electrocutions. Code is 99% of the way there and is already a pretty large read. As more vehicles come with V2H capabilities, perhaps we'll see a move that allows for G floating via special connector because it's safe. Without a special connector with appropriate labeling, they'll say "well this device can be used as an extension cord for purposes other than this and isn't safe when used like that" (thus my suggestion of tiny length, no other utility).

(now to be honest, I'd bet against this because they don't factor cost into equations and will just say "spend another 4k" because they're lazy like that. Possibly the only exception would be a "professionally" installed system with variables verified. Professional is in quotes because I've already seen people with ME installed interconnects that aren't compliant and only safe w/ a GFI protected generator -- besides I'm sure you've lost count of half-assed "professionally" installed electrical systems you've had to rectify)

The challenge is still open for someone to show a short or electrocution hazard present with the dogbone when used as described.

 

[Hullguy]

Portable generators are NG bonded else the grounding conductor is useless for anything plugged into it requiring a ground. This is a requirement of portable generators. Furthermore when connected to a structure a portable generator must be connected to earth when connected to a structure with switched neutral. This is true for pretty much every inverter out there as well unless it's made specifically for grid-tie and will be labeled as such. Otherwise the system is double bonded. Because the frame is serving as the 'ground', the frame itself must be earthed.

Code isn't the magic shield you believe it to be. 28,000+ code compliant structures catch fire each year. Furthermore as previously discussed it's a catch-all and doesn't address situations such as this where the 'generator' has additional protections built in to prevent electrocutions. Code is 99% of the way there and is already a pretty large read. As more vehicles come with V2H capabilities, perhaps we'll see a move that allows for G floating via special connector because it's safe. Without a special connector with appropriate labeling, they'll say "well this device can be used as an extension cord for purposes other than this and isn't safe when used like that" (thus my suggestion of tiny length, no other utility).

(now to be honest, I'd bet against this because they don't factor cost into equations and will just say "spend another 4k" because they're lazy like that. Possibly the only exception would be a "professionally" installed system with variables verified. Professional is in quotes because I've already seen people with ME installed interconnects that aren't compliant and only safe w/ a GFI protected generator -- besides I'm sure you've lost count of half-assed "professionally" installed electrical systems you've had to rectify)

The challenge is still open for someone to show a short or electrocution hazard present with the dogbone when used as described.

I’m not going to disagree with your points!
But what I’m advocating by not trying to use a shortcut, the ground cut off a plug, and using a neutral switching code compliant transfer switch maintains your existing ground system in your house. Using the dogbone eliminates your houses existing ground system.

 

[Mszczewski]

I’m not going to disagree with your points!
But what I’m advocating by not trying to use a shortcut, the ground cut off a plug, and using a neutral switching code compliant transfer switch maintains your existing ground system in your house. Using the dogbone eliminates your houses existing ground system.

Just trying to understand, how would using a dogbone without the ground remove the ground from the house? Isn't the main panel in your house still connected to the ground rods that are required by the NEC?

 

[Hullguy]

Just trying to understand, how would using a dogbone without the ground remove the ground from the house? Isn't the main panel in your house still connected to the ground rods that are required by the NEC?

It is, but using a dog one without the ground leaves the house ground disconnected.

 

[AndreB]

This is a Neutral Switching Transfer switch which is NEC compliant and the proper way to use the Powerboost as an electrical source.

Exactly, to my knowledge, this is the way to go.

 

[Mszczewski]

It is, but using a dog one without the ground leaves the house ground disconnected.

Due to the possible charge imbalance between the truck and the physical earth that your ground rods are in?

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