EV Charger Risks: Home Charging Installation Risks and Advice [by Munro Live]

[Whiskymaker]

I installed a 14-50 originally, just using the Ford Mobile charger - works fine, no hint of anything getting warm. I like to overengineer for the future, as heck, we might end up with more than one EV since we love this one so much.

You're pulling the wire anyway, so I installed #4. Yes, it's stiff and a pain, but my garage has a new GE panel (10 years old is new in my book). I put on a 50A breaker and a 14-50 box from Midwest Electric. Certainly a budget receptacle compared to the Hubbel, but NO sign of problem.

I don't know if it was Black Friday or what, but Emporia energy dropped their price to $399.99 so I grabbed one on Amazon. Ordered a 60A breaker, so in a few days I'll have the potential for 48A charging as I'll direct wire the unit. Now I can put the mobile charger in the trunk, where I also have a 24A charger with two different plugs. My Emporia charger should be a super easy install - as I did the hard work ahead of time.

This was DIY job, but unless you're familiar with the codes and have experience I would definitely suggest hiring a qualified electrician. Proper installation, that is, correct wire size and proper torquing, correct breaker size, AND decent components all add up to the best chance of a safe charging situation. In my case, I was able to save big, as I'm probably only in about $800 total WITH the Emporia unit.

Next step is to increase my Solar PV array, and add a battery plant for the house. That will give me the ability to buffer power for emergencies, and also daily while the sun is out, but the car is away. Our net metering rate isn't amazing, so I'd like to keep my electrons myself. Might even get weird with a hydrogen plant...

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[nmope]

wow that was a shocking (pun intended) video. Im definitely going to spend the money and get a licensed electrician who is experienced with EV installs.

 

[mkhuffman]

I installed a 14-50 originally, just using the Ford Mobile charger - works fine, no hint of anything getting warm. I like to overengineer for the future, as heck, we might end up with more than one EV since we love this one so much.

You're pulling the wire anyway, so I installed #4. Yes, it's stiff and a pain, but my garage has a new GE panel (10 years old is new in my book). I put on a 50A breaker and a 14-50 box from Midwest Electric. Certainly a budget receptacle compared to the Hubbel, but NO sign of problem.

I don't know if it was Black Friday or what, but Emporia energy dropped their price to $399.99 so I grabbed one on Amazon. Ordered a 60A breaker, so in a few days I'll have the potential for 48A charging as I'll direct wire the unit. Now I can put the mobile charger in the trunk, where I also have a 24A charger with two different plugs. My Emporia charger should be a super easy install - as I did the hard work ahead of time.

This was DIY job, but unless you're familiar with the codes and have experience I would definitely suggest hiring a qualified electrician. Proper installation, that is, correct wire size and proper torquing, correct breaker size, AND decent components all add up to the best chance of a safe charging situation. In my case, I was able to save big, as I'm probably only in about $800 total WITH the Emporia unit.

Next step is to increase my Solar PV array, and add a battery plant for the house. That will give me the ability to buffer power for emergencies, and also daily while the sun is out, but the car is away. Our net metering rate isn't amazing, so I'd like to keep my electrons myself. Might even get weird with a hydrogen plant...

Nice job, Craig. Now relax and drink some of your whiskey.

 

[AZBill]

One of my charger plugs was obviously under rated. This is the charger I use for my Bolt, it maxes out at 32A on a 50A circuit. This morning it had a charging interrupted message, along with a nasty smell in the garage. The circuit breaker had not even tripped off, had to do that manually. The detached RV garage was wired by a licensed electrician when I had it built.

 

[J5hort]

One of my charger plugs was obviously under rated. This is the charger I use for my Bolt, it maxes out at 32A on a 50A circuit. This morning it had a charging interrupted message, along with a nasty smell in the garage. The circuit breaker had not even tripped off, had to do that manually. The detached RV garage was wired by a licensed electrician when I had it built.

Just curious. What gauge wire was being used? How long is the run? And what temperture rating was the connector so far as temperature (60 or 75) and wire material (Cu or Al)?

 

[ddr24]

One of my charger plugs was obviously under rated. This is the charger I use for my Bolt, it maxes out at 32A on a 50A circuit. This morning it had a charging interrupted message, along with a nasty smell in the garage. The circuit breaker had not even tripped off, had to do that manually. The detached RV garage was wired by a licensed electrician when I had it built.

And this is why hiring a licensed electrician, familiar with EV installs, who will pull a permit and get an inspection is the ONLY way to go...so you have someone to turn to assuming you survive the house fire and the insurance company starts to ask questions. The part that scares me is you suggest you DID hire a licensed electrician? Yikes.

 

[Maquis]

One of my charger plugs was obviously under rated. This is the charger I use for my Bolt, it maxes out at 32A on a 50A circuit. This morning it had a charging interrupted message, along with a nasty smell in the garage. The circuit breaker had not even tripped off, had to do that manually. The detached RV garage was wired by a licensed electrician when I had it built.

Thats a typical Leviton Home Depot grade receptacle failure. Chances are the thermal cycling loosened the wire clamps resulting in a meltdown.
Thats also why the Ford Mobile Charger has a thermal sensor in the plug.

 

[Dnorwood98]

One of my charger plugs was obviously under rated. This is the charger I use for my Bolt, it maxes out at 32A on a 50A circuit. This morning it had a charging interrupted message, along with a nasty smell in the garage. The circuit breaker had not even tripped off, had to do that manually. The detached RV garage was wired by a licensed electrician when I had it built.

Buddy and co-worker of mine had this happen last week, plug failed and started a small garage fire. It was installed by a licensed electrician. His ChargePoint is now hardwired.

 

[mkhuffman]

One of my charger plugs was obviously under rated. This is the charger I use for my Bolt, it maxes out at 32A on a 50A circuit. This morning it had a charging interrupted message, along with a nasty smell in the garage. The circuit breaker had not even tripped off, had to do that manually. The detached RV garage was wired by a licensed electrician when I had it built.

This is why direct wiring the EVSE is safer. Even industrial outlets can have a loose connection or wear out after multiple cycles, and cause this problem.

 

[AZBill]

Just curious. What gauge wire was being used? How long is the run? And what temperture rating was the connector so far as temperature (60 or 75) and wire material (Cu or Al)?

The run from my garage subpanel to this outlet is about 45 feet and the wire is copper. But I do not have the other specs for it.

 

[AzCoronaDog]

In my experience:

#1 cause for arcing/melting is improper torquing at the 14-50 receptacle, whether it is commercial or cheap won't matter if it is poorly installed

#2 pulling more than 32amps thru a 14-50 receptacle increases risk of melting unless install is perfect, with commercial grad receptacle, and ambient temp is <80F.

#3 improper wire size (less than 6awg for a short run from breaker to receptacle), or using an undersized extension cord (for either 120v or 240v)

#4 letting charger 'hang' from the plug and wiggle out while under load if the cord moves around; much much much better to mount a bracket on the wall, and put charger body in bracket

#5 with chargers having plug-in 'tails' for both 120v and 240v (like our Ford Mobile Chargers) is not pushing the 'tail' connector all the way into the body of the charger.

This is the best information I have read so far, thanks for sharing!

Munro and company had some just plain wrong information in their video, as do many people posting here. Lots of guessing with no research into the actual standards to back it up.

(TLDR; Lots of misinformation, but be careful with high voltage, high amperage, and regularly check for heat damage.)

There is no 'duty rating' for home electrical outlets or a disconnector, just the rated maximum allowed current draw as labeled, and the maximum current draw for 'continuous load', which is 80% of rated. 'Continuous Load' is defined as 3 hours or longer. So a 14-50 should be able to draw 50 amps for up to 3 hours, or 40 amps when used for more than 3 hours at a time. Of course, only some electrical components are pulled for testing, so it is entirely possible to get faulty items, regardless of brand. And running anything at its maximum rating for long periods of time is going to have some affect on longevity, nothing lasts forever. (The monster 383 motor I built for my old Jeep can attest to how maximum RPM affects the ability of the motor to keep all of its moving parts inside... LOL But it did not burn my house down when it failed.)

From everything I have found, the vast majority of meltdowns for receptacles used for EVSEs are caused by bad wire connections, meaning improper torque on conductor screws. Monro was correct that too much or too little is very, very bad. I don't remember the torque spec for my receptacle, but it was considerable higher than I thought it would be, and would not be easily obtained with just a screwdriver. I used my 1/4" torque wrench with a driver bit, and it took some effort. Bad connections happen for driers and welders and every other thigh amperage plug in equipment too, but EVSEs do draw high current for longer periods than most of those, so the problem tends to show up more easily. And it is never a bad idea to go back after a new installation has been used at high amperage for a bit and recheck the torque at least once. The heat cycle can affect it apparently.

There is no 'industrial" vs "home" or other standard for home electrical connectors. Are some receptacles better quality than others? Absolutely. But they all should be able to handle their maximum rating for under 3 hours at at time, or 80% of their rating indefinitely. A bakelite receptacle will definitely stay together longer than a nylon one under high heat, but if it is getting hot enough to melt nylon, it is not the insulator material that is the problem, it is high resistance and needs to be fixed.

Almost all meltdowns happen at connection points, (all in the video did) and it is always due to high electrical resistance at that point, which means not enough contact, turning the metal into a heater. Besides torque on screws, low contact can be caused by loose fitting contact points between the plug and the receptacle. If you do have to plug and unplug an electrical connection often, this is where the quality of receptacle DOES matter, as receptacles DO have a limited plug / unplug cycles and the quality matters. My EVSE never gets unplugged, and my $12 receptacle has been just fine for almost 2 years. I do check it once in awhile while the car is charging, just to be sure it is not more than warm to the touch. I charge at 30a to be kind to the battery, so my plug has always been cool. To be honest, I wanted a buy little better quality, but there was barely anything on the shelves when I put my outlet in so I had to take what I could get.

I live in AZ, and I can assure you that in the summer, when we get days when the overnight low is near 100 degrees, the breakers and disconnects on my 2 AC units often run at nearly maximum continuous load for well over 3 hours at a time. They hold up without problems, and I believe the reason is proper installation, from breakers, to wire size, to proper torque.

You can never be too careful with high voltage, high amperage equipment of any kind, so my advice is to be proactive and check your EVSE connections regularly for any signs of heat damage. Now that I wrote that, I am going to make a point to check mine this weekend...

 

[J5hort]

The run from my garage subpanel to this outlet is about 45 feet and the wire is copper. But I do not have the other specs for it.

Faily long run. Probably #6 at a minimum (I'd use #4). Can't stress enough proper wire size and temperature rating for connector (90 degree celsius ratings also exist). This along with proper tightening on the lugs, as mentioned, is where most of the focus should be. Placing all the focus or blame on the connector is not entirely accurate. The video fails to take into consideration the entire system and should stress proper ratings.

 

[AzCoronaDog]

And this is why hiring a licensed electrician, familiar with EV installs, who will pull a permit and get an inspection is the ONLY way to go...so you have someone to turn to assuming you survive the house fire and the insurance company starts to ask questions. The part that scares me is you suggest you DID hire a licensed electrician? Yikes.

I did my own install, but I have been working with electrical for decades. I have met many electricians over the years, and while I have learned something from every one, I am 100% positive not one of them was as anal as I am when it comes to doing a quality job with quality materials and tools. Even the best electricians make mistakes, and all the certifications and licenses and insurance in the world will stop your house from burning down when one happens.
When I can't do something myself confidently, I gladly pay a professional. And watch them!

 

[AZBill]

I was able to remove the charger and open up the wall plug box today to investigate the cause. One of the hot leg wire nuts was loose, it slid right off of the wire when I pulled on it, the other three were firmly tightened down. The insulation on the wires and the plastic box the plug was in are totally melted.

I am going to scrap this circuit and replace it with a shorter run on the other side of my garage, next to the subpanel, with direct wiring to the charger.

 

[kennethjk]

I was able to remove the charger and open up the wall plug box today to investigate the cause. One of the hot leg wire nuts was loose, it slid right off of the wire when I pulled on it, the other three were firmly tightened down. The insulation on the wires and the plastic box the plug was in are totally melted.

I am going to scrap this circuit and replace it with a shorter run on the other side of my garage, next to the subpanel, with direct wiring to the charger.

So glad damage was minimal.

can’t a direct wiring have problems with a wire that comes lose no differently from an outlet?

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