Whole home back up - a simple approach

[Johnif]

Hi all,
I just successfully tested my new home back up based on F150 Lightning. Works great.

I have a previously installed 19kW PV Solar system, Solaredge Inverters with Backup Interface feeding a whole house main panel that handles all circuits, except EV charging.

I implemented a whole home back up connected to F150 Lightning, based on:
1) external 50A generator input port (ground wire not connected)
2) 40A breaker in main panel, with standard lockout device to main breaker
3) additional 125A subpanel, with 125A breaker used to switch Neutral line from utility side on/off.

Total material cost approx $200, and another $75 for 50A extension cable to the truck.

I realize it may not be as automated as the HIS system or a single transfer switch, but it allows me to back up my whole main panel without moving any circuits, and it is lower overall cost, and no dealing with Sunrun etc...

 

[Mmiketa]

Im not sure I’m following your whole setup, but you do not want to switch the house neutral AND remove the ground from the truck. You want one neutral-ground bond in your system and you want it to be at the service point ie the truck when in backup mode.

 

[Johnif]

Im not sure I’m following your whole setup, but you do not want to switch the house neutral AND remove the ground from the truck. You want one neutral-ground bond in your system and you want it to be at the service point ie the truck when in backup mode.

Alright, good point, will look into this. Should be easy to apply

 

[TaxmanHog]

This is not a recommended method of connection {dispensing with the ground between truck and generator input or input to main load center}.

There are other threads which deal with the safer way to implement a generator input to transfer switch that includes neutral switching.

 

[Mmiketa]

This is not a recommended method of connection {dispensing with the ground between truck and generator input or input to main load center}.

There are other threads which deal with the safer way to implement a generator input to transfer switch that includes neutral switching.

For what it’s worth, I don’t think it’s unsafe to not bring over your equipment ground from the truck. You service doesn’t bring you a ground either, you make the ground at the house and then bond the neutral. Treat your car as the utility and it’s the same thing, and its built in ground loop will clear its faults. This method is not code legal though which is also important.

 

[Johnif]

For what it’s worth, I don’t think it’s unsafe to not bring over your equipment ground from the truck. You service doesn’t bring you a ground either, you make the ground at the house and then bond the neutral. Treat your car as the utility and it’s the same thing, and its built in ground loop will clear its faults. This method is not code legal though which is also important.

Thanks guys. really appreciate your perspectives. I can implement either option, always good to stick with the rule book

 

[Ford Motor Company]

Hi all,
I just successfully tested my new home back up based on F150 Lightning. Works great.

I have a previously installed 19kW PV Solar system, Solaredge Inverters with Backup Interface feeding a whole house main panel that handles all circuits, except EV charging.

I implemented a whole home back up connected to F150 Lightning, based on:
1) external 50A generator input port (ground wire not connected)
2) 40A breaker in main panel, with standard lockout device to main breaker
3) additional 125A subpanel, with 125A breaker used to switch Neutral line from utility side on/off.

Total material cost approx $200, and another $75 for 50A extension cable to the truck.

I realize it may not be as automated as the HIS system or a single transfer switch, but it allows me to back up my whole main panel without moving any circuits, and it is lower overall cost, and no dealing with Sunrun etc...

That's great to hear, John! The intelligent backup power system of the F-150 Lightning is most certainly awesome, and a feature we're proud to offer!

 

[Its PJ Bia]

I've used this same setup to now power our house through several multi-day outages. I know its not to code, and if I were using this to power our house daily I would probably look at another solution, but this current setup allows me to power all 33 breakers I have in my 200amp panel which no transfer switch would allow me to do. It also cost me $0 because I already had the generator hookup installed for our gas generator.

 

[Zprime29]

That's great to hear, John! The intelligent backup power system of the F-150 Lightning is most certainly awesome, and a feature we're proud to offer!

I don't think you fully understand what's going on here.

 

[Zprime29]

Hi all,
I just successfully tested my new home back up based on F150 Lightning. Works great.

I have a previously installed 19kW PV Solar system, Solaredge Inverters with Backup Interface feeding a whole house main panel that handles all circuits, except EV charging.

I implemented a whole home back up connected to F150 Lightning, based on:
1) external 50A generator input port (ground wire not connected)
2) 40A breaker in main panel, with standard lockout device to main breaker
3) additional 125A subpanel, with 125A breaker used to switch Neutral line from utility side on/off.

Total material cost approx $200, and another $75 for 50A extension cable to the truck.

I realize it may not be as automated as the HIS system or a single transfer switch, but it allows me to back up my whole main panel without moving any circuits, and it is lower overall cost, and no dealing with Sunrun etc...

Does your solar still operate while using the Lightning as the backup source?

 

[v2h8484]

For what it’s worth, I don’t think it’s unsafe to not bring over your equipment ground from the truck. You service doesn’t bring you a ground either, you make the ground at the house and then bond the neutral. Treat your car as the utility and it’s the same thing, and its built in ground loop will clear its faults. This method is not code legal though which is also important.

Just FYI, the way most people are using the neutral transfer switch with the truck is also not code compliant per NEC Section 250.34(B) (https://up.codes/s/portable-and-vehicle-mounted-generators). The truck ground needs to be connected to its own ground rod to be code compliant.

 

[Henry Ford]

Just FYI, the way most people are using the neutral transfer switch with the truck is also not code compliant per NEC Section 250.34(B) (https://up.codes/s/portable-and-vehicle-mounted-generators). The truck ground needs to be connected to its own ground rod to be code compliant.

Will you quote the section you are referring to? I can't find it and I don't understand how requiring a grounding rod on a vehicle makes sense.

 

[Maquis]

Just FYI, the way most people are using the neutral transfer switch with the truck is also not code compliant per NEC Section 250.34(B) (https://up.codes/s/portable-and-vehicle-mounted-generators). The truck ground needs to be connected to its own ground rod to be code compliant.

250.34(B) does not say that.

 

[Johnif]

Does your solar still operate while using the Lightning as the backup source?

Yes, works fine. Have it all inverters wired through Backup Interface, managed separately from main panel.

 

[Zprime29]

Yes, works fine. Have it all inverters wired through Backup Interface, managed separately from main panel.

Very cool. I've been interested in a way to use my solar while backing up power with the lightning. I believe I recall someone saying that excess solar was charging their truck while using the HIS and FCSP setup. Just not sure it's worth that price tag and potential headache.

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