Simple Question: Can I use my current generator (gas/portable) hookup to my box?

[beatle]

...and his house

And my axe!

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[broncoaz]

I think this video has a similar set-up from Fast Lane Truck. Check it out, might help.

They didn’t mention any neutral issues in the video. Is the power boost setup different than the Lightning with respect to the ground fault tripping?

 

[Toby57]

I am a newby here and a retired electrician, maybe I can be some help.
The 240V AC outlet on your Lighting or Pro Power is there for a tool. Such as an air compressor.
Not to run your house.
The 240V has GFCI protection. The GFCI is NOT there to protect you or whatever you plug into it.
It is there to protect your Pro Power and all wiring in the truck.
A GFCI does not trip due to over current.
Removing any of the four conductors removes the GFCI protection and could cause great damage to your trucks system.
This is why Ford wants you to run your house off the charging cord and converter on house instead of truck. Making it very expensive.

 

[Tony Burgh]

I am a newby here and a retired electrician, maybe I can be some help.
The 240V AC outlet on your Lighting or Pro Power is there for a tool. Such as an air compressor.
Not to run your house.
The 240V has GFCI protection. The GFCI is NOT there to protect you or whatever you plug into it.
It is there to protect your Pro Power and all wiring in the truck.
A GFCI does not trip due to over current.
Removing any of the four conductors removes the GFCI protection and could cause great damage to your trucks system.
This is why Ford wants you to run your house off the charging cord and converter on house instead of truck. Making it very expensive.

My thought was that the Lightning gfci tripped because the bonded neutral in the house panel allowed current to return through both the neutral and ground to the truck. That would cause the fault of more than 5mA. If the ground path is eliminated by having another independent ground rod dedicated to the truck (and the portable generator when it’s used instead) the gfci would be eliminated.
Do you think that prevents potential damage to the truck?

 

[broncoaz]

My thought was that the Lightning gfci tripped because the bonded neutral in the house panel allowed current to return through both the neutral and ground to the truck. That would cause the fault of more than 5mA. If the ground path is eliminated by having another independent ground rod dedicated to the truck (and the portable generator when it’s used instead) the gfci would be eliminated.
Do you think that prevents potential damage to the truck?

That would be a much cheaper solution for me than having to install a transfer switch for the neutral.

 

[Tony Burgh]

That would be a much cheaper solution for me than having to install a transfer switch for the neutral.

If the ground wire in the 4 prong plug in the Lightning is there to take stray current away from the the truck (and the gfci trips when power is returned to the truck through the ground line) an independent ground may work. I’d like to hear from an electrician about that.

 

[Toby57]

I hope this helps.
If a 4ma to 6ma current flows from circuit to earth, the GFCI will trip regardless of where the nearest electrical grounded surface is.
The way a GFCI functions is that all of the circuit conductors pass through a single current transformer. Because of Kirchhoff's Current Law, any current flowing 'out' on one circuit conductor must be exactly balanced by current flowing 'in' on the other circuit conductor(s), unless some current is flowing someplace else (eg. a ground fault, or a fault to another circuit). The _net_ current seen by the GFCI is thus zero when the protected circuit is functioning properly. The 'sum of all currents' measurement is what the GFCI is looking at.
Grounding the truck ( not sure how that would be done) with a ground rod or other means you might be grounding two systems together that MIGHT be separate in the truck. IDK.
Because the truck sits on rubber tires the electric systems are already engineered to not need an earth ground.

 

[Toby57]

I tried to quote Tony Burgh. It did not work. I don't know why. Still learning the ways of this forum.

 

[Maquis]

I hope this helps.
If a 4ma to 6ma current flows from circuit to earth, the GFCI will trip regardless of where the nearest electrical grounded surface is.
The way a GFCI functions is that all of the circuit conductors pass through a single current transformer. Because of Kirchhoff's Current Law, any current flowing 'out' on one circuit conductor must be exactly balanced by current flowing 'in' on the other circuit conductor(s), unless some current is flowing someplace else (eg. a ground fault, or a fault to another circuit). The _net_ current seen by the GFCI is thus zero when the protected circuit is functioning properly. The 'sum of all currents' measurement is what the GFCI is looking at.
Grounding the truck ( not sure how that would be done) with a ground rod or other means you might be grounding two systems together that MIGHT be separate in the truck. IDK.
Because the truck sits on rubber tires the electric systems are already engineered to not need an earth ground.

Good summary.
I’ll add that the UL spec for a class A GFCI requires that it trip at a level not greater than 6mA. 4-6 is the generally accepted nominal range seen in practice.
And don’t get hung up about ground rods or other connection to dirt. In the context of an auxiliary power source, it doesn’t do anything.

 

[Tony Burgh]

I’m waiting to hear back from my electrician about my question that Randy and Dave addressed. But what does the ground wire do for the truck if grounding isn’t needed? I think someone else tried bypassing the ground wire but I can’t find that thread.
I don’t want to be electrocuted and I don’t want to fry my truck.

 

[davehu]

You know what I hate. A) My loud, stupid generator B) Spending more money on Ford than I have to. So, if a simple solution exists, awesome!
You guys are awesome. Thank you.... Is anyone else doing this? I mean, I can't be the only one with a generator and a whole house feed that bought a Lightning.

You aren't! just a few weeks before the Lightning "reveal" I sold my 5 year old portable generator with the intent on replacing it with a newer, quieter, one. The Lightning annoucement saved me from buying a $1200 generator! I've now been patiently waiting for my order letter going 18 months without power protection but it will be worth the wait. I already have a transfer switch and a 20ft cable so I'm ready to plug in the Lightning when it arrives! (next spring?)

 

[Maquis]

I’m waiting to hear back from my electrician about my question that Randy and Dave addressed. But what does the ground wire do for the truck if grounding isn’t needed? I think someone else tried bypassing the ground wire but I can’t find that thread.
I don’t want to be electrocuted and I don’t want to fry my truck.

The purpose of the ground wire from the truck is to cause the breaker (GFCI) to trip in case the tool (or whatever is plugged in) has an internal fault that would otherwise cause exposed metal parts to become “hot.”
In the thread you’re referencing, the guy simply didn’t run the ground wire from the truck to the transfer switch. What happens when you do this is that the chassis of the truck is connected to the electrical system ground via the neutral wire (which carrys current) instead of the ground wire. This results in a voltage gradient between the truck chassis and the electrical system ground point because of voltage drop on the neutral. In theory, you could receive a shock if you touched the truck and a grounded object at the same time, but doing so should trip the GFCI in the truck. I don’t believe this could damage the truck.
But regardless, the code-compliant way to use the Pro Power as home backup is through a transfer switch that switches the neutral. You use all 4 wires from the truck without tripping the GFCI.

 

[PV2EV]

I installed the 30A Generac Manual Transfer switch for number of reasons:

- It uses the same Siemens breakers I already have, and supports their tandem breakers.
- Every circuit you move to the transfer switch panel frees circuits on your main panel (for me it allowed installation of the 100A breaker for the FCSP in my main panel)
- The kit includes a really nice input box. There are three part#'s, 6852 MTS only, 6853 MTS w/plastic input box, 6854 MTS w/aluminum input box.
- The MTS is pre-wired with labeled wires, and 1" flex conduit for your main panel run (if needed). I installed mine in the bay next to the main and used a nipple instead.
- The MTS will take a 30A input, but supports far more circuits than that (espeeislly when using tandem breakers), so you will have a choice of what critical loads you want to use.

Considerations:

- The MTS requires a dual pole 50A breaker (feed) from your main panel. This limits the amperage of what you can use during normal operation, so even though you can, don't move too many circuits over.
- If you use tandem circuits, you may need to upsize the conduit/nipple to the main panel for the additional wire.
- In addition to purchasing the 50A breaker that fits your panel (same or related brand), you need to purchase the wire for the 30A gen/truck input (input box to MTS).

Thinking ahead:

As I was running the FCSP conduit/wires from my main panel to the outside wall, I ran another conduit alongside for the input, and installed the input box below the FCSP location. This will allow me to reuse the conduit and 8AWG wire for the Ford/Sunrun HIS if I ever decide to do that (or something similar). The 1" FCSP and 3/4" Input conduit run to a junction box for the FCSP penetration. Then I continued the 3/4" below to thee gen/truck input penetration.

 

[sotek2345]

I’m waiting to hear back from my electrician about my question that Randy and Dave addressed. But what does the ground wire do for the truck if grounding isn’t needed? I think someone else tried bypassing the ground wire but I can’t find that thread.
I don’t want to be electrocuted and I don’t want to fry my truck.

My electrician came back with a quote for setting it up with the Generac transfer switch. ~$2,700, too rich for my blood for the few hours a year we lose power. Extension cords it is!

 

[PV2EV]

Here are a few pics of my MTS install. The junction box is too small per code, but all I could fit.