Could my outlet or 120V charge cord EVSE cause a fire?

[saintlydean]

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[Slapshot28]

How can you possibly believe the outlet was not defective if "the outlet partially pulled from the wall???"

Outlets can go bad quite easily in a relatively short period of time due to things like moisture and corrosion. There is a huge body of experience now with the GM EVSE, and I politely disagree with your electrician. I am certain that a hair dryer would have caused the exact same event in that outlet.

[2BeLivingGreen]

So it sounds like the heat was generated from the plug area not the charger itself? If that is the case, I would tend to agree with Slapshot that it was the plug and not the charger at fault. I am sure you can get another expert opinion, if needed.

[Koz]

An EE with experience building circuiting could answer better but I don't think there is anything the EVSE (or any other plug-in device) could do to cause a fire in properly functioning outlets, with proper wiring connections, properly protected by a breaker/fuse, and fed with properly size sized/insulated wire. The breaker protects the wire and outlet from loads they cannot handle. If the breaker is functioning properly, then the load must have been within its design limits. The problem was most likely a poor wiring connection to the outlet or in the junction box. Poor or loose connections create resistance which generates heat under load. The next most likely issue is with outlet itself. Again, a poor internal connection in the outlet could generate excess heat. What the EVSE does is put higher "stress" on circuits than they may have experienced previously, which exposes the faulty connection. Shorter duration or lower loads would not cause the same amount of heat buildup. It's also possible a connection in the outlet or wiring to it loosened up enough over time and use to become a problem.

No doubt, you should have your EVSE checked but I would be more concerned about the wiring in the home and the quality of the outlets. If the electrician that did the initial work is still in business, you should contact them. Tell them what happened and that you want a whole house inspection. If not them, have another licensed electrician do an inspection.

Edit: Another likely scenario is a worn or otherwise loose receptacle. The plug posts should meet resistance when it engages the outlet. If the outlet's receptacle is "loose", the plug goes in easily without much resistance. That can also crate a poor connection that generates excess heat.

People may say to make sure you install a dedicated 20A circuit for Volt 120V charging but I disagree. It's a good idea to install wiring and an outlet rated for 20A but use a 15A breaker for better protection. It should also be a GFCI outlet or breaker.

[2BeLivingGreen]

Koz you mention a good suggestion. If this outlet is faulty, more than likely, then the rest of the house may be susceptible to the same issue over time. I think to get the wiring/outlet checked out by an EE is a good idea and see if the rest of the house is properly wired and has approved outlets within it. An EE will know if certain brand/style outlets has had more issues in the field than others.

[caronjeff]

Many electricians are skeptical of so called "backstab" outlets. It seems possible for an insufficient length of bare wire inserted to cause a less than perfect connection. Also possible to curl the wire and use the screw connection, but have the wire not fully under the screw head causing a less than perfect connection. I would replace the outlet with a GFI get a new charger and proceed after your inspection.

[BAZINGA]

I'm sure GM will want this charger back since it was identified as the cause. I'm sure the OP has this documented by the local Fire Marshall etc.

But in the meantime I'd pay to have my house inspected to ensure it's up to code or no defects in materials or construction.

[dwvoss]

As a firefighter, I wonder was this just the opinion of one of the firefighters on the scene? In our department, this would have been determined to be an 'electrical fire'. Since the outlet itself was burning, it's a pretty big stretch to lay the blame on the device that was plugged into the outlet.

[bonaire]

Get an electrician to look for faulty wiring in a more "electrician-oriented" way rather than those who have already looked. Was the wire proper for 20A or lower? Was it aluminum rather than copper? Was the socket a $.80 version or something good? Was it back-stab or screw connection? I assume they ruled out loose screw connection in this one.

There are a lot of short-cuts put in place when building newer homes. They tend to rush them more and more. When I end up with an EV, I will have a separate 120V line setup off a sub-panel using the highest quality socket possible. Not convinced I would need a 240V charger.

[Mark Z]

Southern California is notorious for using 14 gauge wire for duplex outlets with 15 amp circuits. It's code, but I wish it wasn't. While this may not be the cause, the loss of electric power when using 14 instead of 12 or 10 gauge causes extra heat and a larger electric bill. Your outlet may have been installed with the quick connect method rather than wired to the screw terminals. It's a possible weak link when a heavy load is attached to the outlet.

Another frustration is how GM used 16 gauge supply wire when designing the original charge cord. This causes extra heat that transfers to the outlet. I used a 20 amp dedicated circuit and Pro Spec outlet and it would still be warm. I'd use a heavy duty industrial series outlet today that is made with larger contact area to the blades to improve connectivity.

Have the charge cord checked by GM. I had a charge cord that ran so hot that the unit would flash red lights and I had to have a fan aimed at it to keep it cool and keep it operational. Finally, GM replaced it with a charge cord that did run cool.