Updated Ford Intelligent Backup Power page (no longer) details 320-Amp Home Service o_O

[rtw819]

[EDIT: As of 1/26/2022 the Ford website no longer indicates the requirement for 320-amp service, but recommends you consult an electrician for home requirements instead! This is much more reasonable.]


Based on recent updates to the Intelligent Backup page:
https://www.ford.com/trucks/f150/f150-lightning/2022/features/intelligent-backup-power/

About 1/3 of the way down the page a graphic states 320 Amp service is required! This seems like an odd number.

I totally get the 100 amp dedicated circuit for the 80-amp Charge Station Pro. That makes perfect sense. Your home has to have sufficient service to cover existing loads plus the new 80 amp charger. That also makes sense.

I wonder if many folks actually have 320 amp service already? (Not us, we've only got 150 amp service and suspected we might likely be looking at an upgrade anyway if we wanted to take full advantage of the 80 amp charger and run the rest of our house.)

Maybe I've missed it, but there aren't 320 amp mains panels that I've ever seen looking at the standard residential stuff on the DIY box store sites? Seems like a pretty odd requirement. Our provider (AEP) website has a request form to upgrade from 100/200/400 to 100/200/400 amp service. Assuming the 80% rule applies, looks like we might have to submit a request for some heavier 400 amp cable runs along with the upgraded meter base (and meter) to cover the 320 amp service requirement. I can't imagine that will be free.

The 320 amp service might either be fed by a 400 amp (non-continuous) meter base at 80%, or a 320 amp meter base with maybe two 150 amp panels somehow, though that doesn't seem quite right either. Maybe they're adding a 100 amp dedicated charger circuit along with the typical modern home's existing 150-200 amp service? Considering they ultimately plan to feed house loads with an inverter and transfer switch, not sure how that would all work with the 320 amp service, that's a hefty transfer switch. Maybe they're expecting to re-wire things a bit to feed a separate backed-up loads panel?


Any electricians out there that might have some insight? Hopefully we'll continue to see more and more information released on the IBP and "Home Integration Solution" as we get closer to deliveries. Unless I'm mistaken, Sunrun doesn't seem to produce products of their own, so they almost have to be using someone else's gear. Should also be fun since they're not in my state.

All of this will be interesting to see if (or how) nicely it will "play" with my home's existing solar back-end of a SolarEdge Backup Interface (whole home backup device with integrated transfer switch and optional standalone generator input) coupled with panels, Energy Hub Inverters and a LG RESU10H backup battery.

Guess I'll have to keep doing research on the Ford/Sunrun Home Integration platform. Are you in the same or a similar boat? Let's keep track of what we learn here!

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[sotek2345]

Good catch, that is really weird. If Sunrun is going to be so picky as to require a certain service size (vs looking at existing loads), I will just get the hardware and have another electrician install it. I only have a 150A service, but relatively low loads. I recently had an EVSE installed for my wife's Mach-e and had them run larger wire to support a 100A circuit (so I only paid for it once). When they did that they said it would be no issue and I wouldn't need a larger service.

 

[beatle]

I'm no elechicken, but it's strange that there is a panel-specific requirement and not just a circuit requirement. I wonder if it has something to do with the two 120v poles that home panels have and their individual load capability?

 

[SteffanG]

I am an electrician in Canada (rules are slightly different).
There is no such thing as a 320A panel or even a 320A breaker. The standard is 60A (rare and sub panels only), 100A, 125A, 150A, 200A, 400A.
A 400A panel is massive in size and cost, not to mention the wiring would be expensive as well.

There should be no reason why they need a 320A service for the inverter. They do not draw high peak currents like a motor does.

The most important thing is to have a transfer switch. Either the main service would need to be taken out of the main panel or a separate subpanel added for the "emergency" loads. The transfer switch is an on/off/on switch (I.e it disconnects one side before it connects the other side) for safety. Backfeeding the panel without a transfer switch and relying on someone turning off a breaker is against code and very unsafe for anyone working on the powerlines (it will back feed the high voltage lines as well, the surge of power would likely trip a breaker, but it is enough that it would possibly kill someone working on the line).

 

[Maquis]

For some reason, convention has taken to calling a 400 amp service “320”. It goes back to the often misapplied 80% rule for continuous loads. In the US homes with a “320 amp” service will normally have 2-200 amp panels.
As mentioned above, a true 400 amp panel is horribly expensive.

 

[adoublee]

This will be required if the truck is ever able to parallel with the grid as a synchronized second source doing "vehicle to grid". In theory the metal bus bar could be overloaded if the multiple sources add up to more than the bus amp rating and the load breakers in total are drawing more than bus rating. So NEC has rules, one being that amps of breakers feeding bus can't add it more than 120% of bus rating if sources are located on opposite sides of loads breakers.

If the truck only becomes a source when the home is isolated from the grid, there is no reason for this requirement.

For nominal 400A of residential electric service, the utility meter sockets are only rated for 320A.

 

[DadBald]

I'm caught up in this a little bit for a current solar installation. It has to do with two power sources on your electric panel. There is a 120% rule for the bus loading. If your panel bus matches your service size, that's considered 100% loading. You have 20% extra you can attach at the opposite end of the panel for backfeeding. This goes for solar, generators, or the lightning as another power source. So if they're calling for 320A minimum service size, it's because you need 64A of backfeed for the lightning.

See here: https://www.cedgreentech.com/article/what-panelboard-sizing-120-rule

I am currently looking for a 400A main panel replacement to give me 60A of backfeed with some headroom, and I can't find any available anywhere. 3 Electricians have backed out and my 4th is telling me just the panel cost is $3000. I called a couple suppliers myself and the cheapest panel I could find was an Eaton 400A panel at $2500. That seems crazy to me.

But yes. In order to backfeed your panel, the BUS size of the panel needs to be rated big enough to handle your primary and secondary power sources together. Note one workaround for this, if you have 150A service, is to upgrade the panel only. Not the service / meter size / feeder size from the utility - keep that at 150A. But a 200A panel with the 120% rule could have a maximum of 240A with backfeed, so 150A service + 64A Lightning backfeed = 214A. You would be under the max load in this configuration and you get around the 320A service size requirement.

 

[sotek2345]

I'm caught up in this a little bit for a current solar installation. It has to do with two power sources on your electric panel. There is a 120% rule for the bus loading. If your panel bus matches your service size, that's considered 100% loading. You have 20% extra you can attach at the opposite end of the panel for backfeeding. This goes for solar, generators, or the lightning as another power source. So if they're calling for 320A minimum service size, it's because you need 64A of backfeed for the lightning.

See here: https://www.cedgreentech.com/article/what-panelboard-sizing-120-rule

I am currently looking for a 400A main panel replacement to give me 60A of backfeed with some headroom, and I can't find any available anywhere. 3 Electricians have backed out and my 4th is telling me just the panel cost is $3000. I called a couple suppliers myself and the cheapest panel I could find was an Eaton 400A panel at $2500. That seems crazy to me.

But yes. In order to backfeed your panel, the BUS size of the panel needs to be rated big enough to handle your primary and secondary power sources together. Note one workaround for this, if you have 150A service, is to upgrade the panel only. Not the service / meter size / feeder size from the utility - keep that at 150A. But a 200A panel with the 120% rule could have a maximum of 240A with backfeed, so 150A service + 64A Lightning backfeed = 214A. You would be under the max load in this configuration and you get around the 320A service size requirement.

This just seems nuts to me (granted Mech-e eng background, not electrical). We have to have an automatic transfer switch anyways to protect line workers (completely agree with this), so you will never have both sources on at the same time. You would need a double failure (automatic transfer switch failure that connects both sources - not even sure if this is possible and a failure that makes the lightning detect that main line has failed) in a max load condition to have any issues.

Edit: For solar this makes sense - you have both sources running in parallel on a regular basis.

 

[Maquis]

I think that using the Lightning in a grid-tied scenario would really be a fringe use case. Someone with solar may want to charge the Lightning off-peak, then feed the utility from the battery on-peak.
Personally, I don’t want to degrade my Lightning battery like this. I want my charge/discharge cycles to be used for driving.

 

[DadBald]

This just seems nuts to me (granted Mech-e eng background, not electrical). We have to have an automatic transfer switch anyways to protect line workers (completely agree with this), so you will never have both sources on at the same time. You would need a double failure (automatic transfer switch failure that connects both sources - not even sure if this is possible and a failure that makes the lightning detect that main line has failed) in a max load condition to have any issues.

Edit: For solar this makes sense - you have both sources running in parallel on a regular basis.

Perhaps with an ATS it's different. I'm not clear on that.

 

[jefro]

The plan for this is one can have either an ABT or an MBT or some smart device that can do both upon command.
No way you wll be able to power much more than 100A of circuits.

 

[Griddlez]

I still don't understand how a 200amp service can't handle this. What am I missing...

 

[MickeyAO]

With more bi-directional EVSE coming (see Wallbox's Quasar 2) I wonder if we are somehow limited to using the Sunrun product?

 

[Maquis]

With more bi-directional EVSE coming (see Wallbox's Quasar 2) I wonder if we are somehow limited to using the Sunrun product?

SunRun is an installer, not a product.

 

[MickeyAO]

SunRun is an installer, not a product.

OK, tied to their solution then.

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