Charger Possible Source of Garage Fire

[DaveA]

I've used the Rivian portable charger for almost 3 years in a Nema 14-50 plug, but do not disconnect it ever so the contacts don't loosen. ( I have a second one in the truck) 32 amp constant draw on a Nema is probably the max I'll ever be comfortable with. It gets warm but never "can't hold my hand there for 10 seconds" warm. If I needed more juice, definitely hard wiring as some have said.

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[Riviot]

Well my garage gets pretty hot in the summer so I assume the heat threshold is adjustable. Any particular brands recommended?

I got this one because my garage isn't wired into my security system. It's a standalone battery operated alarm from the UK. Most cheap American ones need to be wired in.

FireAngel Heat Alarm with 10 Year Sealed for Life Battery, FA6720-R https://a.co/d/drTxYhM

After my third literal false alarm with the Simplisafe smoke detector had the fire department calling me in the middle of the night, I ditched the dust detecting piece of crap and put an old-school unconnected alarm in its place.

 

[beeglowbot]

Electrical issues are a genuine threat if not treated with respect and professionalism.

The images below are from a previous NEMA 14-50 that my electrician installed for one of my EVSEs in the garage. I caught it before it burned my house down.

PSA - Only install commercial-grade connectors if you're using a plug-in EVSE. Ideally, hardwire. Consumer / dryer-grade are simply not rated for the duty cycle of a constant 40-amp draw, and will inevitably fail.

Man I've seen so many of these melt and catch fire. From my perspective, it's just not worth the time and money saved from not hardwiring your charger and making sure everything is code compliant.

 

[TexasBob]

I've had a plug melt due to a loose connection as well. Recently my homeowners insurance company sent me these devices from Ting that monitor all of the electrical circuits and notify you if there is an anomaly. (Homeowners provided them for free but they sell on website for $99.)

https://www.tingfire.com/

 

[FraserC]

The NEMA plugs definitely have limitations that 'heavy users' (frequent plug/unplug cycles) need to be aware of, because dirt and corrosion on the pin/socket present high resistance and arcing. But the less visible side of the connection where the wires are clamped inside the receptacle are more likely to go undetected. Also the person that makes these connections had better have a good understanding of the critical 'area of contact' in this regard. A competent installer will ensure this integrity by clamping hard enough to deform the copper wires inside the receptacle, which can easily increase this critical area of contact by a huge margin. A properly clamped wire will not present a resistor in the circuit, an improperly clamped wire is a time bomb.

One more useful comment; the photo's showing extensive heat damage DEFINITELY heated the plug, so if you use a connection like this, then it's a good idea to pay attention to this, and if the plug is warm/hot, investigate!

 

[hilld]

I've used the Rivian portable charger for almost 3 years in a Nema 14-50 plug, but do not disconnect it ever so the contacts don't loosen. ( I have a second one in the truck) 32 amp constant draw on a Nema is probably the max I'll ever be comfortable with. It gets warm but never "can't hold my hand there for 10 seconds" warm. If I needed more juice, definitely hard wiring as some have said.

The problem is not the unplugging and plugging back in, it is the repeated heating and cooling cycles of the charging that will weaken the spring tension of the receptacle. Other issues are often the actual wire to receptacle connection, the heating and cooling and loosen up the contact and that is where the melting, arching and eventually burning can start from, especially if the screw mushes (spreads) the wires under the screw with stranded connectors.

 

[bigsky]

DIY or probably installed by Dryer Outlets 'R' Us.
As for outlets used to charge EVs, even if outlet is EV rated, constant plugging and unplugging, session after session of long sustained maximum amperage, what could go wrong?

Hard wired wall charger for me always. Have had two Tesla wall chargers professionally installed by companies verified experts in such installations. Metal conduit, correct wiring, correct wiring torque, 60 A breaker, etc. Going in 5 years without ever having any issues and about 500 charging sessions.

Already have 3 smoke detectors in my garage. Thank you for bringing up heat detectors!
Getting them, too.

 

[NY_Rob]

If you have to run your EVSE off an outlet, please consider limiting your charge rate to 30amps max vs charging at full rated EVSE capacity. And, inspect the outlet often!

 

[DaveA]

If you have to run your EVSE off an outlet, please consider limiting your charge rate to 30amps max vs charging at full rated EVSE capacity. And, inspect the outlet often!

 

[Eeyore]

Electrical issues are a genuine threat if not treated with respect and professionalism.

The images below are from a previous NEMA 14-50 that my electrician installed for one of my EVSEs in the garage. I caught it before it burned my house down.

PSA - Only install commercial-grade connectors if you're using a plug-in EVSE. Ideally, hardwire. Consumer / dryer-grade are simply not rated for the duty cycle of a constant 40-amp draw, and will inevitably fail.

FYI, Hubble is such a brand name that it is commonly call out in electrical specs.

I'll wager that the fault with that outlet was the connection for the wire wasn't properly tightened. With stranded wire, after the initial tightening, you have to wiggle the wire around to get the strands seated, then tighten it again. If you fail to do this, the heat/cool cycle will eventually loosen the connection. That causes the heating shown on this plug.

But, yah, only buy high quality, name brand electrical components, like Hubble.

 

[NovemberBravo]

FYI there is a GoFundMe for the family
(https://www.gofundme.com/f/support-the-browns-after-house-fire)

 

[Joules Burn]

FYI, Hubble is such a brand name that it is commonly call out in electrical specs.

I'll wager that the fault with that outlet was the connection for the wire wasn't properly tightened. With stranded wire, after the initial tightening, you have to wiggle the wire around to get the strands seated, then tighten it again. If you fail to do this, the heat/cool cycle will eventually loosen the connection. That causes the heating shown on this plug.

But, yah, only buy high quality, name brand electrical components, like Hubble.

Agree. And from switch breaker panel to outlet or hardwired unit, torque the connections!

 

[mikehmb]

FYI, Hubble is such a brand name that it is commonly call out in electrical specs.

I'll wager that the fault with that outlet was the connection for the wire wasn't properly tightened. With stranded wire, after the initial tightening, you have to wiggle the wire around to get the strands seated, then tighten it again. If you fail to do this, the heat/cool cycle will eventually loosen the connection. That causes the heating shown on this plug.

But, yah, only buy high quality, name brand electrical components, like Hubble.

No no no!!

Be super careful - Hubbell is great but they do offer different grades of product. The one shown is standard grade that gets installed all the time for dryers etc. many electricians didn’t understand this when they installed home L2 units.

You must use a commercial grade if you want to support the duty cycle of an EVSE.

 

[Joules Burn]

No no no!!

Be super careful - Hubbell is great but they do offer different grades of product. The one shown is standard grade that gets installed all the time for dryers etc. many electricians didn’t understand this when they installed home L2 units.

You must use a commercial grade if you want to support the duty cycle of an EVSE.

Agree. Like this one..

https://store.hubbell.com/product/1...aC5y_3xgyaPGbg3tJTxPfdGHYlzMKgzRoCpSMQAvD_BwE

 

[JM.]

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