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

[techmonkie]

All,

Just recently purchased a F150 Platinum with the 7.2kw PPO option with the intention of being able to use it to power the house in case of outages then found all of the info related to the potential issues associated with using an interlock setup due to the bonded neutral configuration our trucks have. After doing a bunch of reading/research and consulting a couple of electricians, I reached out to Reliance to get some info on one of their transfer switches with the intention of offloading 8-10 circuits into a sub-panel type configuration. The tech rep I spoke with had mentioned this is a well known issue and had proposed something I hadn't really thought about until he mentioned it, and the more I think about it, the more I wonder if it would potentially serve as a 'safe' stopgap for going the interlock route.

It appears to be common knowledge that disconnecting the ground lead from the plug effectively tricks the PPO system to not see the bonded neutral setup on the main panel side, eliminating the ground fault event that would result in the truck not powering the main service panel, but his proposed workaround was to actually wire the ground lead to the neutral lead on the truck side of the plug, effectively 'grounding' the house side of the plug and providing a valid path to ground in the event it is required through the interlock/inlet plug when on generator power.

'Good' example: Power comes off of the hot lead from the generator, through inlet plug and 30/50A breaker backfeeding the panel and then goes to the requesting circuit/load's hot line. Return power comes through the circuit's neutral line, back through the panel's neutral and ultimately out through the neutral prong on the 240v plug back to the generator.

'Bad' example: Same scenario, but in the event there is a grounding event, power would be returned through the grounding wires in the recepticle/appliance/etc, back to the ground bus on the main panel, which would then jump via the bond strap/screw over to the neutral bus and have a path back through the neutral prong on the 240v plug back to the generator.

The net result in both instances is the same: Power has a valid path back to the generator source via the neutral lead. Granted it's not adhering to the spirit of having a separately grounded line via the 4th prong on the 240v plug, but ultimately the ground and neutral are bonded on the 'back side' of the inverter generator via the neutral bond which ultimately gets the returned power back to the same location. In this instance we're tying the 2 circuits together on the generator side of the plug prior to it going back into the truck.

Full disclosure: Not an electrician, have a basic understanding of electrical theory, haven't played with AC a whole lot. On paper, it seems like this meets the requirement of 'separating' ground and neutral from the generator's standpoint so it won't result in the ground fault, and it provides a real and meaningful ground path back to the generator from the house in the event there's an issue. I fully expect it's not going to meet code standards and may not be the most optimal way of doing it, but as far as I can tell, I can't see anything overtly dangerous short of 'you're running neutral and ground back on the same prong'. I had initially thought this would be akin to a bootleg ground, but as I understand it, in the bootleg instance you're trying the ground to neutral at the *receptacle* level in order to provide a path for the ground prong in the receptacle to return power, but as a result are also potentially energizing the ground lead, which is dangerous. In my example, you're passing any power picked up from either neutral or ground explicitly back to the truck on just the neutral lead.

Am I just crazy, or would this serve as a safer alternative for trying to use PPO in a full house/interlock capacity than just disconnecting the ground lead. I really don't want to go the transfer switch method if I can avoid it as my longer term goal is to get a 50A capable generator to power the house, and I want to have this available as a shorter term stopgap measure.. also it seems like a pretty interesting problem to try to solve.

Thanks in advance for your guys' help. I've learned a lot by reading some of the previous threads on this subject and I'm hoping this maybe introduces another option for us to consider, assuming I'm just not completely stupid with my theory crafting.

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[UGADawg96]

Paging our resident guru on this topic @Hullguy

And welcome to the forum @techmonkie from someone who grew up in RVA and visits often

 

[techmonkie]

Lol I've actually seen his name pop up a LOT on the threads I've been reading here. Looking forward to hearing his insight on the subject.

 

[Hullguy]

All,

Just recently purchased a F150 Platinum with the 7.2kw PPO option with the intention of being able to use it to power the house in case of outages then found all of the info related to the potential issues associated with using an interlock setup due to the bonded neutral configuration our trucks have. After doing a bunch of reading/research and consulting a couple of electricians, I reached out to Reliance to get some info on one of their transfer switches with the intention of offloading 8-10 circuits into a sub-panel type configuration. The tech rep I spoke with had mentioned this is a well known issue and had proposed something I hadn't really thought about until he mentioned it, and the more I think about it, the more I wonder if it would potentially serve as a 'safe' stopgap for going the interlock route.

It appears to be common knowledge that disconnecting the ground lead from the plug effectively tricks the PPO system to not see the bonded neutral setup on the main panel side, eliminating the ground fault event that would result in the truck not powering the main service panel, but his proposed workaround was to actually wire the ground lead to the neutral lead on the truck side of the plug, effectively 'grounding' the house side of the plug and providing a valid path to ground in the event it is required through the interlock/inlet plug when on generator power.

'Good' example: Power comes off of the hot lead from the generator, through inlet plug and 30/50A breaker backfeeding the panel and then goes to the requesting circuit/load's hot line. Return power comes through the circuit's neutral line, back through the panel's neutral and ultimately out through the neutral prong on the 240v plug back to the generator.

'Bad' example: Same scenario, but in the event there is a grounding event, power would be returned through the grounding wires in the recepticle/appliance/etc, back to the ground bus on the main panel, which would then jump via the bond strap/screw over to the neutral bus and have a path back through the neutral prong on the 240v plug back to the generator.

The net result in both instances is the same: Power has a valid path back to the generator source via the neutral lead. Granted it's not adhering to the spirit of having a separately grounded line via the 4th prong on the 240v plug, but ultimately the ground and neutral are bonded on the 'back side' of the inverter generator via the neutral bond which ultimately gets the returned power back to the same location. In this instance we're tying the 2 circuits together on the generator side of the plug prior to it going back into the truck.

Full disclosure: Not an electrician, have a basic understanding of electrical theory, haven't played with AC a whole lot. On paper, it seems like this meets the requirement of 'separating' ground and neutral from the generator's standpoint so it won't result in the ground fault, and it provides a real and meaningful ground path back to the generator from the house in the event there's an issue. I fully expect it's not going to meet code standards and may not be the most optimal way of doing it, but as far as I can tell, I can't see anything overtly dangerous short of 'you're running neutral and ground back on the same prong'. I had initially thought this would be akin to a bootleg ground, but as I understand it, in the bootleg instance you're trying the ground to neutral at the *receptacle* level in order to provide a path for the ground prong in the receptacle to return power, but as a result are also potentially energizing the ground lead, which is dangerous. In my example, you're passing any power picked up from either neutral or ground explicitly back to the truck on just the neutral lead.

Am I just crazy, or would this serve as a safer alternative for trying to use PPO in a full house/interlock capacity than just disconnecting the ground lead. I really don't want to go the transfer switch method if I can avoid it as my longer term goal is to get a 50A capable generator to power the house, and I want to have this available as a shorter term stopgap measure.. also it seems like a pretty interesting problem to try to solve.

Thanks in advance for your guys' help. I've learned a lot by reading some of the previous threads on this subject and I'm hoping this maybe introduces another option for us to consider, assuming I'm just not completely stupid with my theory crafting.

This method would violate the intent of the NEC. Electrical equipment, in this case the Cord from the truck is supposed to be Underwriters Laboratory, UL, listed. If you modify the way the plug is wired you lose the UL listing protecting you.
I’m surprised the manufacturers rep suggested this wrong method of trying to beat the Code.
If I were you and had the intent of having a 50 amp generator installed in the future, I’d wire the plug with #6 copper wire, buy a 120/240 volt 50 amp neutral switching transfer switch, change the breaker in the transfer switch to a 30 amp, 2 pole breaker. When you make the switch you change the outside receptacle to a 50 amp inlet from a 30 amp inlet an change the 30 amp breaker in the transfer switch back to the 50 amp breaker.
Feel free to ask any questions. Jim

 

[techmonkie]

This method would violate the intent of the NEC. Electrical equipment, in this case the Cord from the truck is supposed to be Underwriters Laboratory, UL, listed. If you modify the way the plug is wired you lose the UL listing protecting you.
I’m surprised the manufacturers rep suggested this wrong method of trying to beat the Code.
If I were you and had the intent of having a 50 amp generator installed in the future, I’d wire the plug with #6 copper wire, buy a 120/240 volt 50 amp neutral switching transfer switch, change the breaker in the transfer switch to a 30 amp, 2 pole breaker. When you make the switch you change the outside receptacle to a 50 amp inlet from a 30 amp inlet an change the 30 amp breaker in the transfer switch back to the 50 amp breaker.
Feel free to ask any questions. Jim

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?

 

[Hullguy]

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?

If you are going to do a whole house generator setup then there really are no cost effective ways to use the Powerboost as an electricity source except by running extension cords from it. They make adapters that plug into the 30 amp,120/240 volt truck outlet.
The whole house automatic transfer is a sweet setup and depending on the size of the house and electrical needs it should be able to carry all of your electric needs. It’s usually an easier install than the individual circuit transfer switches

 

[Cobra129]

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?

This method would violate the intent of the NEC. Electrical equipment, in this case the Cord from the truck is supposed to be Underwriters Laboratory, UL, listed. If you modify the way the plug is wired you lose the UL listing protecting you.
I’m surprised the manufacturers rep suggested this wrong method of trying to beat the Code.
If I were you and had the intent of having a 50 amp generator installed in the future, I’d wire the plug with #6 copper wire, buy a 120/240 volt 50 amp neutral switching transfer switch, change the breaker in the transfer switch to a 30 amp, 2 pole breaker. When you make the switch you change the outside receptacle to a 50 amp inlet from a 30 amp inlet an change the 30 amp breaker in the transfer switch back to the 50 amp breaker.
Feel free to ask any questions. Jim

Jim, I hate to interrupt but while on this subject I would respectfully like to ask you a question since you are considered one of the knowledgeable ones on this subject. I've been researching using the PB as a power source for my home in case of emergencies. I'm a FL resident, '23 PB 7.5, and one who is totally ignorant on electricity other than is scares me.... Its now hurricane season and I've had an electrician adapt my Florida Power and Light (FPL) outside wall panel with the appropriate parts and adapters a couple of years back.

I currently have a Pulsar, dual fuel 12K generator for potential outages from hurricanes which could last for days. With the Pulsar, all I have to do now is engage the safety panel, plug in the generator to the FPL panel, select what items/appliances I would like to run from the interior house panel (individual breakers) and go from there. I'm pretty certain this Pulsar generator has a 'Bonded' Neutral.

With all the discussion about Bonded Neutral or Floating Neutral, I am curious to know that to use the PB as a backup or even as a main power source for my home, if needed, can I just purchase an appropriate cable and connect it straight to the FPL panel or do I need any other adapters or switches?

Additionally, I've heard of 'soft start' switches for initiating high load appliances, any thoughts on that?

Thank you for your time and any comments are greatly appreciated, Jim.

Cheers, Allan

 

[Hullguy]

Jim, I hate to interrupt but while on this subject I would respectfully like to ask you a question since you are considered one of the knowledgeable ones on this subject. I've been researching using the PB as a power source for my home in case of emergencies. I'm a FL resident, '23 PB 7.5, and one who is totally ignorant on electricity other than is scares me.... Its now hurricane season and I've had an electrician adapt my Florida Power and Light (FPL) outside wall panel with the appropriate parts and adapters a couple of years back.

I currently have a Pulsar, dual fuel 12K generator for potential outages from hurricanes which could last for days. With the Pulsar, all I have to do now is engage the safety panel, plug in the generator to the FPL panel, select what items/appliances I would like to run from the interior house panel (individual breakers) and go from there. I'm pretty certain this Pulsar generator has a 'Bonded' Neutral.

With all the discussion about Bonded Neutral or Floating Neutral, I am curious to know that to use the PB as a backup or even as a main power source for my home, if needed, can I just purchase an appropriate cable and connect it straight to the FPL panel or do I need any other adapters or switches?

Additionally, I've heard of 'soft start' switches for initiating high load appliances, any thoughts on that?

Thank you for your time and any comments are greatly appreciated, Jim.

Cheers, Allan

Thanks for asking for advice Allen!
To be honest I’d be using the Powerboost to get fuel for the Pulsar. It can run your AC and most of your house. The Powerboost won’t be able to run as much as the pulsar.
The generator is supposed to be marked if it is a bonded neutral generator. I dont see any markings in any pictures I brought up.
heres a video explaining how to find out if you are interested.

Or you can look at the transfer switch and see if the neutral is switched. If it is then the generator is neutral bonded. If not it is a floating bond and the truck won’t work!
If you find it is a bonded neutral generator then you can get a 120/240v 30 amp male to 50 amp female changeover plug.
Your wiring is sized for 50 amps and the truck will only put out 30 amps.
this only works if the generator is neutral bonded!

 

[techmonkie]

If you are going to do a whole house generator setup then there really are no cost effective ways to use the Powerboost as an electricity source except by running extension cords from it. They make adapters that plug into the 30 amp,120/240 volt truck outlet.
The whole house automatic transfer is a sweet setup and depending on the size of the house and electrical needs it should be able to carry all of your electric needs. It’s usually an easier install than the individual circuit transfer switches

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

 

[Hullguy]

Search for 120/240v 30a male to 120/240v 50amp female generator changeover

 

[Cobra129]

Thanks Jim, really appreciate the information. I plan to use the Portable Gen as the primary source and the PB as a backup if something fails or there are extended power outages where nothing is available, like during Hurricane Andrew. Already tested the Pulsar on the home at the time of the additions to the FPL power panel and it works great

I have seen the Pulsar advertised (same model, dual fuel 12K) and they said 'Bonded Neutral.' Will be checking anyway. I will purchase the 120/240v 30-amp male to 50-amp female changeover plug as insurance. We live on the coast and when these hit, if they hit, they can be devastating, just want to be prepared. Again, Jim, appreciate the information. I hope this hurricane season is as quiet as the last season...

Cheers, Allan

 

[techmonkie]

Search for 120/240v 30a male to 120/240v 50amp female generator changeover

Sorry, I should have been more specific. You had referred to a neutral switching transfer switch, and I took your meaning to be that there is a potential way to perform the neutral/ground separation that would be required in a way that could be done in a whole house/interlock capacity. Ultimately it seems to me that the bonded neutral in the main panel is what causes this not to work and is what would need to be solved via some form of wizardry.

I understand the generac 6582 solves that issue by literally switching the leads when it transfers from line to generator by disconnecting the main panel service from the protected circuits and explicitly puts them on the generator hots, neutral, and ground which is unbonded in the transfer panel itself. Are you implying there would be a way to perform a similar action at the whole house level that I haven't come across yet via some kind of transfer switch?

Sorry to pepper you with all of this, I'm just very interested in coming up with a viable way to skin this cat.

 

[Hullguy]

Sorry, I should have been more specific. You had referred to a neutral switching transfer switch, and I took your meaning to be that there is a potential way to perform the neutral/ground separation that would be required in a way that could be done in a whole house/interlock capacity. Ultimately it seems to me that the bonded neutral in the main panel is what causes this not to work and is what would need to be solved via some form of wizardry.

I understand the generac 6582 solves that issue by literally switching the leads when it transfers from line to generator by disconnecting the main panel service from the protected circuits and explicitly puts them on the generator hots, neutral, and ground which is unbonded in the transfer panel itself. Are you implying there would be a way to perform a similar action at the whole house level that I haven't come across yet via some kind of transfer switch?

Sorry to pepper you with all of this, I'm just very interested in coming up with a viable way to skin this cat.

No there isn’t a whole house option that I know of. Ask away!

 

[techmonkie]

No there isn’t a whole house option that I know of. Ask away!

OK so we know that not grounding the plug between house and truck is a bad idea, but in practice has been proven that it can power an interlock. Tieing the ground to the neutral at the truck side of the plug should similarly have the same result and provide a 'valid' ground path from the backfed circuit, albeit not a true ground relative to the generator.

If electrically one of the purposes of a bonded neutral is to get the flow of electricity back to the source in the event of a ground path via the ground/neutral bond, and from a practical standpoint at the house circuit side electricity would recognize the ground as valid and ultimately ship it back to the neutral line, can you help me understand the hazard involved? I recognize that this isn't being done the way it was meant to be, so I'm trying to understand electrically how this change would introduce risk that I may not be fully understanding, aside from 'that's not how we intended it and you shouldn't do it'. I'm sure I'm missing something here from a risk standpoint, I just want to make sure I understand it properly. I understand it's a workaround at best, I just wanna make sure I'm not going to blow anything up because I missed something stupid.

Thanks again!

 

[Hullguy]

OK so we know that not grounding the plug between house and truck is a bad idea, but in practice has been proven that it can power an interlock. Tieing the ground to the neutral at the truck side of the plug should similarly have the same result and provide a 'valid' ground path from the backfed circuit, albeit not a true ground relative to the generator.

If electrically one of the purposes of a bonded neutral is to get the flow of electricity back to the source in the event of a ground path via the ground/neutral bond, and from a practical standpoint at the house circuit side electricity would recognize the ground as valid and ultimately ship it back to the neutral line, can you help me understand the hazard involved? I recognize that this isn't being done the way it was meant to be, so I'm trying to understand electrically how this change would introduce risk that I may not be fully understanding, aside from 'that's not how we intended it and you shouldn't do it'. I'm sure I'm missing something here from a risk standpoint, I just want to make sure I understand it properly. I understand it's a workaround at best, I just wanna make sure I'm not going to blow anything up because I missed something stupid.

Thanks again!

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

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