Backup power without a SunRun inverter?

[steven]

As long as it is located behind a utility-approved transfer switch, anything wrong with feeding a home grid with a Lightning's 240-volt output port?

 

[frunk]

I don't know how to answer this. on a transfer switch grid power will connect to one place in the transfer switch and on the other side the transfer switch the Ford Lightning will be connected so when the grid power go out the switch will open the contacts on the grid side and close the Lightning contacts to power the house then when the grid power comes back on the transfer switch will open the Lightning contacts and close the grid contacts to let the grid power the house. so the transfer switch only allows one power input at a time.

 

[steven]

There was a missing detail - a manual transfer switch that would complete the circuit to the Lightning socket. It would be thrown after my inverter triggered the automatic transfer switch and when my smaller AGM battery bank was getting close to depletion.

I'm told however this wouldn't work because it would bypass the equalizer (regulating power frequency?) built into the inverter. I don't understand this. If the Lightning can supply 240V of equalized power on its own, why can't it supply that power to my home grid?

 

[frunk]

There was a missing detail - a manual transfer switch that would complete the circuit to the Lightning socket. It would be thrown after my inverter triggered the automatic transfer switch and when my smaller AGM battery bank was getting close to depletion.

I'm told however this wouldn't work because it would bypass the equalizer (regulating power frequency?) built into the inverter. I don't understand this. If the Lightning can supply 240V of equalized power on its own, why can't it supply that power to my home grid?

I don't know the answer. This is what i think. If you just plunged in to the bed of the truck with an extension cord to your transfer switch it could feed 240 volt A/C to your house but if you want to use ford auto switch charger then the truck is sending DC voltage back to the house so you would need an inverter on the wall to convert it to A/C to feed your house.

 

[steven]

I don't know the answer. This is what i think. If you just plunged in to the bed of the truck with an extension cord to your transfer switch it could feed 240 volt A/C to your house but if you want to use ford auto switch charger then the truck is sending DC voltage back to the house so you would need an inverter on the wall to convert it to A/C to feed your house.

Do you know if the 240 V A/C port can supply power at the full 9.6kW rate or would I have to use the Ford autoswitch charger to get that rate?

 

[frunk]

Do you know if the 240 V A/C port can supply power at the full 9.6kW rate or would I have to use the Ford autoswitch charger to get that rate?

It has a fuse on it its a 30 or 40 amp fuse but the 9.6kw it can supply. you can set how far to drain the battery in the ford apps but you will not be able to draw more amps then the fuse rating. if you use the ford charger setup you can supply more amps. i can not remember the fuse and amp rating i know i posted them but i can't find it. i hope this make sense The amp tell you how much power it can supply and the 9.2Kilo watts tells you how long it can supply that power in time.

 

[steven]

(Given my level of electrical knowledge, I am already way over my head so I hope this makes sense!) So as long as I don't attempt to draw power at a rate that would blow the fuse - something north of 9.6kW - I should be OK? And if I do, how hard is it to replace that fuse?

 

[steven]

(Given my level of electrical knowledge, I am already way over my head so I hope this makes sense!) So as long as I don't attempt to draw power at a rate that would blow the fuse - something north of 9.6kW - I should be OK? And if I do, how hard is it to replace that fuse?

Missed the last sentence of your reply. Instead of "something north of 9.6kW" it is simply attempting to draw more than 30 to 40 amps?

 

[frunk]

Let me say it this way. 9.2 kw means the battery can supply this much power in one hour. I think what you need to understand in kilowatts is how long a battery can supply electrical voltage and amperage is how many thing the battery can run. Let me say it this way. if you have a battery and you connect it to a 30 watt light it could run for 10 day but if you connect the same battery to 10 30 watt light it may only run for one day these are not real numbers. if you connect your house to the 240 volt 30 amp connection in the bed of the truck you will be able to run light, TVs, internet and blender. but it will not run a/c unless you turn all other things off

 

[MarkC]

There was a missing detail - a manual transfer switch that would complete the circuit to the Lightning socket. It would be thrown after my inverter triggered the automatic transfer switch and when my smaller AGM battery bank was getting close to depletion.

I'm told however this wouldn't work because it would bypass the equalizer (regulating power frequency?) built into the inverter. I don't understand this. If the Lightning can supply 240V of equalized power on its own, why can't it supply that power to my home grid?

Steven - what is your status on this? Be aware that the Sunrun home system taps the Lightnings DC connections of the CCS "charger" port, inverts the DC to AC to go to the home safely. If you have some other "inverter" with battery backup and you connect that to the AC outlets on the trucks bed, then you run the risk of destroying both inverters IF your existing inverter is not "grid forming" and somehow mimics the Lightnings AC outlet voltage/frequency characteristics. I don't know if anyone has tried this!

 

[Kstype]

Hi All,

I was reading through this thread. The 240 V Twistlock in the rear of the Lightning can supply 7.2 KW to your house like a traditional generator would - to get the 9.6 your would need to use the full power from the DC ports on the lower port of the CCS port on the side - this is more complicated and why you need the inverters and the extra gear that SunRun provides.

In my case, the master electrician I use for everything installed my ChargeStation Pro. We installed that in the Garage and he also wired my home for my 6.5KW gas generator several years ago, which included a manual service cutoff switch in the main circuit breaker and a female twistlock port outside (the same twistlock that is in the rear of the Lightning).

When he ran the conduit for the ChargeStation Pro he made room for an additional cable and junction box so that he could place an additional female twistlock port next to my ChargeStation Pro that matches the original one for the generator out back.

He will then add a manual transfer switch between the original twistlock port out back and the new one in the garage. This will allow me to decide if I want to run the house from the 7.2 KW truck, or spin up my 6.5 KW gas portable generator.

The new process for me would be to:

1. Cut off the service provider with my manual cutoff switch at the main breaker (protecting any line workers from any power from generator or truck).
2. Decide if I want to run from truck or generator and set the Transfer switch accordingly. I will likely keep it in Truck mode most of the time (which will cutoff the original exterior twistlock so both cannot be on simultaneously).
3. Turn on the Truck - activate the ProPower Onboard bed 7.2 KW circuits A and B (they are auto combined in the 240 twistlock). This is now feeding power to the house.
4. Turn on the individual circuits in the house that I want energized during the outage (I could probably do this in step 1 but I like to bring things up gradually).

Now - during this time I do have UPS’s on my Ubiquity Wifi/Cable Modem/SAN Storage and at my desk and my wife’s desk so those will stay running while I work thru the manual steps above so we should really have no downtime.

I’m excited to see this in action when the time comes.

 

[MarkC]

Let us know as your setup is probably the best way to utilize the V2H capabilities - at least at this time.

I'd sure like to know about the SunRun V2H/V2G capabilities that automatically switches the trucks battery power to the home on an outage (via the CCS DC port). Does the inverter limit the power to 4kw? Has anyone found a way to combine a solar input that can be used while disconnected from the grid? During this disconnect mode, can the Lightning be charged in any way? It seems that the Ford's "bidirectionality" of DC power from the battery directly and AC power only to do the charging is problematic for true "V2G". Can a hybrid inverter provide a "work-around"?

 

[Kstype]

Excellent questions but ones I have not investigated because the solution I have is sufficient for my needs.

 

[Ssob]

Hi All,

I was reading through this thread. The 240 V Twistlock in the rear of the Lightning can supply 7.2 KW to your house like a traditional generator would - to get the 9.6 your would need to use the full power from the DC ports on the lower port of the CCS port on the side - this is more complicated and why you need the inverters and the extra gear that SunRun provides.

In my case, the master electrician I use for everything installed my ChargeStation Pro. We installed that in the Garage and he also wired my home for my 6.5KW gas generator several years ago, which included a manual service cutoff switch in the main circuit breaker and a female twistlock port outside (the same twistlock that is in the rear of the Lightning).

When he ran the conduit for the ChargeStation Pro he made room for an additional cable and junction box so that he could place an additional female twistlock port next to my ChargeStation Pro that matches the original one for the generator out back.

He will then add a manual transfer switch between the original twistlock port out back and the new one in the garage. This will allow me to decide if I want to run the house from the 7.2 KW truck, or spin up my 6.5 KW gas portable generator.

The new process for me would be to:

1. Cut off the service provider with my manual cutoff switch at the main breaker (protecting any line workers from any power from generator or truck).
2. Decide if I want to run from truck or generator and set the Transfer switch accordingly. I will likely keep it in Truck mode most of the time (which will cutoff the original exterior twistlock so both cannot be on simultaneously).
3. Turn on the Truck - activate the ProPower Onboard bed 7.2 KW circuits A and B (they are auto combined in the 240 twistlock). This is now feeding power to the house.
4. Turn on the individual circuits in the house that I want energized during the outage (I could probably do this in step 1 but I like to bring things up gradually).

Now - during this time I do have UPS’s on my Ubiquity Wifi/Cable Modem/SAN Storage and at my desk and my wife’s desk so those will stay running while I work thru the manual steps above so we should really have no downtime.

I’m excited to see this in action when the time comes.

Thanks for the great write-up. I plan for something similar, using my new PowerBoost, which has the 7.2KW ProPower Onboard. The difference is that I do not already have a generator port installed, so I am starting from scratch.

There is an issue, at least with the PowerBoost hybrid, caused by the bonded neutral on the truck interfacing with the bonded neutral at the panel. This will cause a ground fault detection by the truck and prevent the transfer of power. The issue and a solution can be found in this video:

. Do you know if the same issue exists for the Lightning and its ProPower Onboard system? How will your electrician solve it?

As far as connecting the ProPower to the house, there are two ways: 1. Use a master lockout or 2. Use a transfer switch. My understanding is that by using the transfer switch, the loads (circuits) which will be fed by backup power are pre-determined to prevent overloading the backup power source (in the case of the ProPower Onboard, 7.2kW). Using the master lockout, one must manually select the circuits to be powered by backup power by placing the breakers in the On position for each circuit. This requires that the homeowner pay attention to the loads on each circuit and manage the transfers so as to not overload the backup source.

Question for you: Do you know if you can still use any of the 120V outlets on the ProPower Onboard while having the 240V connected as the backup? If so, does it mean you have to manage the loads on those so as not to exceed the 7.2kW capacity, as well?

Steve

 

[Kstype]

Thanks for the great write-up. I plan for something similar, using my new PowerBoost, which has the 7.2KW ProPower Onboard. The difference is that I do not already have a generator port installed, so I am starting from scratch.

There is an issue, at least with the PowerBoost hybrid, caused by the bonded neutral on the truck interfacing with the bonded neutral at the panel. This will cause a ground fault detection by the truck and prevent the transfer of power. The issue and a solution can be found in this video:

. Do you know if the same issue exists for the Lightning and its ProPower Onboard system? How will your electrician solve it?

As far as connecting the ProPower to the house, there are two ways: 1. Use a master lockout or 2. Use a transfer switch. My understanding is that by using the transfer switch, the loads (circuits) which will be fed by backup power are pre-determined to prevent overloading the backup power source (in the case of the ProPower Onboard, 7.2kW). Using the master lockout, one must manually select the circuits to be powered by backup power by placing the breakers in the On position for each circuit. This requires that the homeowner pay attention to the loads on each circuit and manage the transfers so as to not overload the backup source.

Question for you: Do you know if you can still use any of the 120V outlets on the ProPower Onboard while having the 240V connected as the backup? If so, does it mean you have to manage the loads on those so as not to exceed the 7.2kW capacity, as well?

Steve

Thanks very much for the information - I am relaying this to my electrician as I was not aware of this possibility - I will let you know what he says. As for the manual transfer switch - I already have the critical circuits marked in my panel because that is what I do now with my existing generator solution so it’s not a concern for me - just BAU.

I believe you can use the 120 plugs in combo with the 240 as long as you are not overloading the entire draw but I am not entirely sure so may want to ask Ford.

 

[MarkC]

Although I have not yet decided on the best home backup solution, this topic of neutral/ground bonding is important to understand since dealing with a non-grounded vehicle can "potentially" cause issues. The video attached previously does correctly provide the bond at the truck, isolated the main panel neutral/ground during backup and re-establishes the bond when on utility mains via the third neutral/ground terminal on the "transfer" switch.
The purpose of the bond is to provide a low resistance path for any imbalances in the 120 volt (split) phase usages via the neutral wire. This prevents a voltage potential being developed near the imbalanced load usage points with possible harm if a person is exposed between the neutral and any nearby ground. It solves a problem that was created by using split phase systems. IMO (I'm not an electrical engineer and can stand to be corrected!), using the 120 volt outlets while using the backup system without the proper bonding (with proper wire sizing), could cause this issue. I'd be surprised if the Pro Power did not shut down on ground fault without this proper bonding anyway. I've actually experienced this with my charge controller when using a battery backup system to charge my EV.
The issue of having to limit the power usage with Pro Power backup will either require a separate, properly sized sub-panel or pre-select the breakers on the main panel before making the transfer - or the "generator" breaker will open if the loads are too high. On the previous video, it appears that too high of loads will trip the Pro Power system breaker as the "transfer switch" appears to feed directly to the main panel disconnect. Again, stand to be corrected as I don't have a working system at this time.