mobile charger with garage outlet

[FlasherZ]

Instructions with the Ford Mobile Charger indicate that the temperature, both internally and at the supply plug, is monitored and the output throttled if an over temp condition is detected. This causes the dreaded amber light, reduced output reported by quite a few people. I don’t find anything to indicate that voltage drop is monitored, but I found it interesting that the 14-50P temperature is.

I think this is in response to Tesla's initial UMC, which had a nasty habit of melting the adapter plugs when pins got too hot, or when receptacles ended up with loose wires.

I always recommend re-torquing the connections on receptacles and EVSE terminals after a month or two, when expansion / contraction cycles have taken place.

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[beatle]

I think this is in response to Tesla's initial UMC, which had a nasty habit of melting the adapter plugs when pins got too hot, or when receptacles ended up with loose wires.

I always recommend re-torquing the connections on receptacles and EVSE terminals after a month or two, when expansion / contraction cycles have taken place.

Yes, that happened to me. My gen1 UMC melted my Leviton 14-50. Some say it's a cheap receptacle that caused the problem. This might be true, but it could also be the heat cycles eventually getting the best of it after ~27 months or so.

Similarly this summer I found my 50A breaker trip due to heat after only 30-45 minutes. (My panel is in the basement where it is in the low 70s even in the summer.) I removed the wires from the breaker, put them back in and torqued them down good again. No more problems and the temperature is now just over ambient. Since this was at the breaker side, it could affect any EVSE, hardwired or plugged in.

 

[FlasherZ]

I appreciate the info about the NEC, I still think 1 or 2 things will happen. The breaker is going to flip, or the truck is going to regulate how many amps it's drawing based on heat of the outlet. Looking at all the SAE17772 standards, and onboard charger documentation it seems like the auto regulate feature is standard across the board. In either case, it's really going to depend on the onboard charger that's on the F150 Lightning, once I get my truck, I will see if it's a Ford design or a 3rd party design.

The J1772 standard (not SAE 17772) defines the protocol by which the truck learns of the EVSE's capacity - the "auto regulate" as you describe. However, the next question is whether or not the EVSE actually knows how much current to advertise to the EV... In the Ford Charge Station Pro (FCSP), there is a rotary switch the installer sets to indicate the charge current that should be advertised, which must be 80% of the circuit ampacity.

Portable EVSE's need to be able to tell the EV what current to draw as well, and especially since many of these EVSE's can use multiple plug types. So the Ford mobile connector advertises 30A if you are using the NEMA 14-50 plug attached, or 12A if you are using the NEMA 5-15 plug. Tesla's mobile connector does the same thing - each adapter plug "tells" the connector, usually via a resistor, what kind of receptacle it is plugged into.

However, what that EVSE cannot tell you via J1772 is:
(*) Whether there's anything else connected to the same circuit, perhaps like a garage freezer that's sharing the same 120V circuit you've plugged into
(*) Whether an adapter is being used, perhaps like a 30-amp dryer plug to 50-amp RV receptacle

In that case, the EVSE will happily tell the truck to draw 12 amps from that 120V circuit or 30/32A from that 240V circuit, even though there are other loads or devices that may limit it.

And yes, the second-final line of defense, short of your fire department visiting to put out the fire in your electrical system, is that the OCPD (breaker) is likely to trip with too much current. However, YOU DO NOT WANT TO EXERCISE THIS. This is why it's important that Ford (and other manufacturers) provide the ability to reduce charge current in the vehicles. I've seen several 30A receptacles melt when 30A continuous loads are pulled through them. A 30A dryer turns on its heating element for a few minutes maximum at start-up, then shuts off and gives the various parts of the circuit time to cool... an EV keeps the load going for HOURS and that's why the requirement to size the circuit at 125% of the EV charging load is there.

As far as the truck's charger goes, it can only "see" electrical characteristics of the power it gets delivered, and that's pretty much limited to seeing voltage drop as amps go up. If the voltage drops too rapidly compared to the current ramp-up, then it means that there is excess resistance somewhere (which is probably being turned into heat). Tesla monitors this and cuts its current by 25% if it "sees" too much resistance. It's unclear whether Ford does that, mostly because without using OBD monitoring, you can't even see how much the truck is drawing.

Probably best just to install a dedicated circuit anyways, has anybody ripped the firmware from the Ford Charging Pro Station? It's pretty pricey for what is basically just an inverter.

Newer versions of the code say that EVSE equipment must only be connected to branch circuits dedicated for the purpose. That's not going to stop people from "borrowing" a 120V receptacle on the outside of a hotel that trips a breaker when the housecleaning staff vacuums, though.

The FCSP is not an inverter. It's even simpler -- it's an intelligent switch. It advertises current to the truck, the truck tells it to turn on, it then closes a switch to give power to the truck.

 

[FlasherZ]

Similarly this summer I found my 50A breaker trip due to heat after only 30-45 minutes. (My panel is in the basement where it is in the low 70s even in the summer.) I removed the wires from the breaker, put them back in and torqued them down good again. No more problems and the temperature is now just over ambient. Since this was at the breaker side, it could affect any EVSE, hardwired or plugged in.

Yes - most of us are blessed with branch circuits and loads that will mostly work and it's intermittent enough that things can cool down even if a connection is not torqued fully.

An EV charging load is the largest load that any residence will experience in terms of concentrated demand. Most homeowners just don't realize that.

I re-torque all my breaker connections every 2 years, only because I've seen failures (and I experienced the good ole' Federal-Pacific Electric panel issues that nearly burned my house down in California when breakers failed to trip even under dead short).

 

[Maquis]

Yes - most of us are blessed with branch circuits and loads that will mostly work and it's intermittent enough that things can cool down even if a connection is not torqued fully.

An EV charging load is the largest load that any residence will experience in terms of concentrated demand. Most homeowners just don't realize that.

I re-torque all my breaker connections every 2 years, only because I've seen failures (and I experienced the good ole' Federal-Pacific Electric panel issues that nearly burned my house down in California when breakers failed to trip even under dead short).

If I were an electrician, I’d refuse to install an EVSE in a home with a FPE panel.

 

[FlasherZ]

If I were an electrician, I’d refuse to install an EVSE in a home with a FPE panel.

Most do. They see it as an upsell opportunity as well - service panel changes are good profit. Same goes for Zinsco.

In my case, a copper crimp splice loosened (used instead of wire nuts in some cases), and the insulation started melting on the wire from high heat. Eventually, a dead short was created in the wiring when enough insulation melted and copper touched. Breaker didn't trip and a giant glowing wire started burning stuff in the wall. We started seeing power artifacts and I smelled an intense burning smell and pulled the main as fast as I could.

If I weren't home, or another 10-15 minutes, the place would have burned.

 

[Maquis]

Most do. They see it as an upsell opportunity as well - service panel changes are good profit. Same goes for Zinsco.

In my case, a copper crimp splice loosened (used instead of wire nuts in some cases), and the insulation started melting on the wire from high heat. Eventually, a dead short was created in the wiring when enough insulation melted, creating a dead short. Breaker didn't trip and a giant glowing wire started burning stuff in the wall. We started seeing power artifacts and I smelled an intense burning smell and pulled the main as fast as I could.

If I weren't home, or another 10-15 minutes, the place would have burned.

The problem is that when an electrician tells somebody they need their panel replaced when all they asked for is a quote to add a circuit, they think they’re being had. They’ll eventually find a handyman or trunk slammer to do what they want. Not everyone, of course, but all it takes is one.

 

[FlasherZ]

The problem is that when an electrician tells somebody they need their panel replaced when all they asked for is a quote to add a circuit, they think they’re being had. They’ll eventually find a handyman or trunk slammer to do what they want. Not everyone, of course, but all it takes is one.

I admit I have run into that - I make it clear that installing an EVSE is going to cost them minimum of about $4-5k because of a panel upgrade and that I would never, under any circumstances, add an EV charging load to an FPE or Zinsco panel.

There is no law that demands FPE and Zinsco panels be replaced, but many insurance companies will refuse to underwrite a policy for a home once they know one of the panels is present. Most inspectors will flag it and buyers may demand compensation to have it replaced.

Now, with that said, if they absolutely refuse, there are some options... Connecticut Electric makes "safe" breakers for FPE and Zinsco panels. With proper bus bar inspection (and replacement if necessary), they can be made safer than reusing an old FPE breaker that's lying around. Zinsco breakers had a tendency to melt the bus bars and Connecticut Electric sells replacements for them to maintain a Zinsco panel that can't be replaced for whatever reason.

I then make it very, very clear that a panel swap-out is best, but ultimately it's their decision.

I point them at some home inspection web sites (not electrician sites) - one example:
https://homeinspectioninsider.com/federal-pacific-breakers-panel/

There is plenty of talk out there about FPE. I tell them to do their own research, and then I relay my own story about a house minutes from burning to the ground due to an FPE breaker failure.

 

[jefro]

The truck won't regulate at all ever. It won't even back out of the garage when it burns down.

If a breaker trips due to heat then there is something wrong. The circuit should be designed to work correctly without a breaker ever tripping.

 

[FlasherZ]

SAE is who created and maintains the J1772 standard and many others related to the automotive industry.

Yes, you called it the SAE 17772 standard - it's the J1772 standard.

You also helped convince me building my own EVSE is the right way to go. I have about 50 feet of 6/3 leftover from when I rewired my house and replaced my panel after Hurricane Laura. 4k or 5k to replace a panel is just...I hope its gold plated for that money. There is also no federal law, or state law that prohibits a home owner from performing upgrades or maintenance themselves. The same goes for insurance companies, as long as you pass their inspection good to go.

The panel upgrade is usually about $3k-$3.5k, then the EVSE install on top of it usually makes it about $4-5k.

You are correct that there is no law that prohibits a homeowner from performing their own work, subject of course to adherence to building codes, codified n law.

However, insurance companies can refuse to underwrite you for any reason they'd like -- having an FPE or Zinsco panel is a common one, and if you lack evidence of an inspection, that's another one.

Good luck in building your own EVSE.

 

[MickeyAO]

Yes, you called it the SAE 17772 standard - it's the J1772 standard.

It is actually the SAE J1772 standard. Why are you beating him up because he dropped the J?

 

[Amps]

"There will be fires"

 

[FlasherZ]

It is actually the SAE J1772 standard. Why are you beating him up because he dropped the J?

I didn't beat him up. He said it was the "SAE 17772 standard" and in reply, I told him it was the J1772 standard... then he brought up that SAE is the body that makes it up, when that wasn't even a part of the conversation. He dropped the J, added the extra 7. I was simply clarifying it for other posters who may come across it and look for the SAE 17772 standard, which doesn't exist.

That's all. I do feel creating his own EVSE is going to be a significant hill to climb, but the biggest issue I have is the original advice that it's fine to run 30A EV charging load through a 30V receptacle and the breaker would handle any issues... that is incorrect and seriously unsafe advice. Breakers don't trip at 30.00000001 amps, and plenty of 30A receptacles have melted under continuous loads of 30A.

 

[MickeyAO]

He dropped the J, added the extra 7.

OK, adding an extra 7 is grounds to call him out!
Now, if really does try to build his own EVSE, he is a fool that is beyond help and will burn his house down...but let's call him out for slight mistakes on nomenclature!

 

[FlasherZ]

OK, adding an extra 7 is grounds to call him out!
Now, if really does try to build his own EVSE, he is a fool that is beyond help and will burn his house down...but let's call him out for slight mistakes on nomenclature!

Please read the original post, where I said this:

The J1772 standard (not SAE 17772) defines the protocol by which the truck learns of the EVSE's capacity - the "auto regulate" as you describe. However, the next question is whether or not the EVSE actually knows how much current to advertise to the EV... In the Ford Charge Station Pro (FCSP), there is a rotary switch the installer sets to indicate the charge current that should be advertised, which must be 80% of the circuit ampacity.

I don't think it's crazy to let others on this thread know that it's the J1772 standard and not the 17772 standard. I didn't call him names, I didn't attack him, I just simply corrected it and then went into the details of what the protocol can do and what it can't. And then when he thought I was arguing over what the SAE is, I said that I was correcting the standard #. I really don't get your problem with that - especially since you also deal with highly technical matters with batteries.

It was an extension of the conversation where he said the truck would "regulate how many amps it's drawing based on heat of the outlet", which is untrue (although the EVSE might include a feature to limit its pilot current). So I described what the EVSE-EV systems *can* do and what they *can't*.

Have a great weekend.

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