Pro Charger install/Home Backup Generator Inlet

[swtaylor89]

Finally took the plunge and self installed the Ford Pro Charger after having it sit in the garage for 8 months, as well as adding a generator inlet to use for backup home power. Thanks to others here, a few youtubers and existing knowledge of electrical work was able to make it happen. See below for pics, open to feedback and or questions. Was sharing the Tesla charger all this time which ran into some issues sometimes when both our vehicles were low. As well the Lightning was causing the Tesla to overheat and it would throttle down to 4kwh which was painful. Getting pretty steady 16kwr charge rate on the Pro and back to 8kwh on the Tesla. Anybody seeing anything different?

Main parts
Pro Charger Tesla Charger(existing)
1" Liquidtight 3/4
3awg wiring 6awg
100 amp 50amp

1 1/2" conduit body to make the turn into the wall, and then up to the bottom side of the main panel. Could not line up the back of the sub with the main due to the expanded wall area, so had to go out the bottom, the a small service loop in the wall to make the 90 into the body then panel.

30 amp Reliance generator inlet. Grounded body to house ground, but not to plug so as to not double up on the Lightning's ground. 10 gauge wiring.
Didn't go the route of a neutral switch panel because I didn't want to limit to only 8 circuits. Home has a ton of circuits and really didn't want to just pull 8 out.

125 amp Square D Homeline Sub 8 slots. 2 awg aluminum service wire used to power sub, used aluminum for flexibility in making those turns.

Some main points:

Had to rearrange multiple breakers in main panel to make room for a 30amp dual pole for the gen inlet so that I could use the interlock kit. As well as add a 125amp subpanel to power the pro charger and existing Tesla charger. Plus to make room for an under construction pool.

Subpanel now holds the two car charger breakers and a couple garage ones, with some room for expansion. Surface mounted everything to avoid annoying drywall work later, plus house ground and fire suppression system also already routed in this wall.

Ran the truck on Pro Power for 2 hours, noticed no issues at all! HAVE to remember to turn off Solar, as if you are drawing less than you're generating, then the truck will get upset as it's not designed to get backfeed on power in that outlet. Wish there was some sort of double interlock for this situation.

Would really like to be able to run ACs off the truck. Need to look further into soft starts for our unit to see if it can keep it below a 30 amp draw. We don't have a lot of power outages, but we do have a lot of demand response events from SCE where the ACs are turned up higher or off. Would also like to look into, when I'm home, powering the home from the truck during 4pm-9pm and then recharging after 9pm to cut our elec rate down by half during that time. I just don't know if that would be more of a cost savings then not doing so and keeping solar on during that time.

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[Maquis]

A couple comments:

Feeding the subpanel with #2AL on a 125A breaker is definitely a violation. #2AL is only good for 95A.

To compliantly install those 2 EVSEs on a 125A subpanel, the sum of their ratings can’t exceed 125A. Derating the FCSP to 48A with the dial would work. That would result in 50A for the Tesla and 60A for the FCSP for a total of 110A. But that doesn’t fix the undersized feeder.

 

[Wesley]

From the picture I couldn't tell if you have separated the ground and neutral in the sub-panel

 

[swtaylor89]

From the picture I couldn't tell if you have separated the ground and neutral in the sub-panel

Hello, sure did! Neutral and ground definitely separated in the sub panel. Thanks.

 

[Maquis]

From the picture I couldn't tell if you have separated the ground and neutral in the sub-panel

There are separate ground and neutral busses. Nothing is landed on the neutral because his 120V circuits are GFCI - the neutrals land on the breaker.

 

[Wesley]

My bad. I should have looked closer!

 

[swtaylor89]

A couple comments:

Feeding the subpanel with #2AL on a 125A breaker is definitely a violation. #2AL is only good for 95A.

To compliantly install those 2 EVSEs on a 125A subpanel, the sum of their ratings can’t exceed 125A. Derating the FCSP to 48A with the dial would work. That would result in 50A for the Tesla and 60A for the FCSP for a total of 110A. But that doesn’t fix the undersized feeder.

Hello, thanks for the feedback.
The size of the AL was a contention point. Read several sites saying #2 was ok since Ford FCSP only pulls at max 80amp. 80% of 125 is 100 AMP which is what the wire is rated for. AL 1/0 would have been a sure bet, but was concerned about space and being able to make the turns into the boxes so went with #2.
The cars are set to charge at completely different times. Mine right at 9pm to stop at 4am, and the Tesla is set to charge later in the morning, so they're not running at the same time.
Thoughts? Appreciate the insight.

 

[Maquis]

Hello, thanks for the feedback.
The size of the AL was a contention point. Read several sites saying #2 was ok since Ford FCSP only pulls at max 80amp. 80% of 125 is 100 AMP which is what the wire is rated for. AL 1/0 would have been a sure bet, but was concerned about space and being able to make the turns into the boxes so went with #2.
The cars are set to charge at completely different times. Mine right at 9pm to stop at 4am, and the Tesla is set to charge later in the morning, so they're not running at the same time.
Thoughts? Appreciate the insight.

#2 AL is definitely only rated for 90A (I mistakenly said 95 above). There are provisions in the code where it can be used for a 100A service, but only if it’s feeding the entire home. You definitely don’t meet that provision.
The safest minimum thing you can do is replace it with #1 (or #3 copper) on a 100A breaker.

Not using the two chargers at the same time is safe, but the NEC doesn’t recognize that as way to undersize the feeder.

Here‘s the ampacity chart. You have to use the 75C column.

 

[Pioneer74]

It's also a code violation to have an empty breaker space in the main panel. You need to install a blank or another breaker to plug it.

 

[swtaylor89]

It's also a code violation to have an empty breaker space in the main panel. You need to install a blank or another breaker to plug it.

Thanks figured so, pool breaker going in there any day now. Will see if I have a spare laying around I can through in there in the meantime.

 

[Henry Ford]

30 amp Reliance generator inlet. Grounded body to house ground, but not to plug so as to not double up on the Lightning's ground. 10 gauge wiring.
Didn't go the route of a neutral switch panel because I didn't want to limit to only 8 circuits. Home has a ton of circuits and really didn't want to just pull 8 out.

I'm pretty sure this is a code violation. I'll let those more well versed in electricity explain why it's a bad idea.

 

[Maquis]

I'm pretty sure this is a code violation. I'll let those more well versed in electricity explain why it's a bad idea.

See post 14 in this thread.

 

[Pioneer74]

See post 15 in this thread.

I think you mean post 14.

 

[Maquis]

I think you mean post 14.

Fixed, thanks.

 

[Jseis]

I appreciate these discussions. Our garage 125 amp utility panel is on a separate meter than the house 200 amp panel. I inspected it closely one day as the previous owners (originally had it built) installed a second floor ADU above the garage. I was standing there looking at and realized the following:

Range, two baseboard heaters, hot water tank, dryer/washer, hot tub, fridge, freezer, microwave, coffee maker, lights, welder outlet. Then the apartment 120v and garage 120V circuits. In total drawing well over capacity and how that 240V 125 amp breaker never tripped floored me. I turned off the range, demo’s the ancient hot tub, turned off the baseboard heat and reminded myself to not use the 240 V radial saw, table saw, welder until I solved this. I used the dryer 8 AWG (everything is copper) for the CP Home Flex set at 30 amps. I’d like to set it higher but that’ll have to wait.

Then I said to the S.O. We are going to need a bigger service. The additive E.V. electrical demand could be.. shocking. Most homes in our area would be hard pressed to add a 240v 40 amp circuit for one L2 charger. Historically, a 200 amp service was good enough but with all electric homes, 300 amp is now the norm. Maybe more if you are L2 charging the equivalent of two ER Lightnings.

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