A story has been making the rounds about Chevrolet Volt charger cords discoloring because of excessive heat, even melting and burning owners.
We know these anecdotes are not new to readers here, as one publication has cited GM-Volt owners and even based its speculation of the ultimate cause – one that is not GM’s fault – on a GM-Volt forum member’s post.
But before we get to that, as background, the cord in question is the standard one included to plug into household 120-volt outlets, not a dedicated, 240-volt Level-2 line.
A volt recharges in one of the Carolina states, where Chevrolet reports the car will be available through dealers next week.
All Cars Electric reported another Volt driver wrote on Facebook that the temperature of his Volt cord was well past the point of coming down with a fever.
“I actually measured the temperature of my unit and reported it to GM directly. I measured 51 degC (124 degF) on the [short] cord and the plug when the plug was connected to a 20 Amp rated 120V socket,” he told the Facebook Chevy Volt Owners group. “GM stated that was within their specifications and OK.”
GM otherwise knows about these issues, and is replacing them under the three-year bumper-to-bumper warranty, but they have not been updated to a new design, said GM Spokesman Rob Peterson. An unknown number of the earlier cars came with a cord believed to be more susceptible to overheating.
Another GM-Volt member All Cars Electric quoted reported being burned by a cord’s metal plug.
“My 110v cord got so hot it caused a 2nd degree burn to my wrist when one of the prongs brushed against me while winding it up,” wrote a GM-Volt.com forum member from Delaware. “I didn’t notice discoloration, the plug is close to the car so I usually had about 2 winds left around the EVSE and the day of the burn I was preconditioning the A/C immediately before unplugging the car.”
Further mining GM-Volt reader comments, All Cars Electric, speculated the ultimate concern may not be GM’s fault at all, but may be simply faulty wiring or overloaded circuits. Following is the account the publication based this on:
“Last Friday I parked the Volt in my carport and plugged it into the same 120v outlet that I have been using for the last month. An hour later the house experienced a power surge. Seeing that a pair of (ganged) 70 amp circuit breakers that feed the sub panel in the carport had tripped, I went to the carport. There I smelled smoke and saw that a slot, 1 1/2″ long and 1/4″ wide, had been burned through the steel faceplate of the sub panel.
When the responding fire fighters removed that faceplate we saw that a feed wire had partially melted its insulation and had completely burned through under the slot.
My electrician replaced the burned out feed wire (black, No. 6 size) and determined that the failed wire had been supplying not only the Volt’s outlet, but two air conditioning units, resulting in an imbalance, such that the black side of the circuit was carrying almost 20 amps more current than the red side. The Volt’s outlet has now been re-wired to the red side and I have used it for an uneventful charge cycle.
I certainly do not blame the Volt in any way, as it was simply the (big) straw that broke the back of the electrical system. Clearly I had too much on one circuit. No one, so far, has been able to tell me why the feed wire burn through occurred prior to the circuit breakers opening.
I plan to have an independent electrician review all circuit loads and I offer this only as a cautionary tale to other Volt owners and welcome feedback from this group.”
One poster showed this discolored cord.
This same poster later followed up, as follows:
“Member 719 was indeed correct in that my 6 gauge feed wires were too small for the subpanel load. I have upgraded to 4 gauge wires which the electricians say are good for 85-90 amps. To be conservative I have kept the original 70 amp circuit breaker that protects these wires and also downgauged the breaker that protects the Voltec Charge Cord outlet from 20 to 15 amps (in accordance with the recommendations that come with the cord set).”
The moral of the story?
“The condition (worn, damaged or age) of the electrical outlet in the wall is often the culprit due for the increase in temperature to the UL certified cord,” Peterson said. “If the AC wall plug feels hot while charging, then the owner should simply unplug the charge cord and have the AC wall outlet replaced by a qualified electrician.”
So, in sum, make sure your household outlet is not overloaded and to code. A Level-2 charger with its own dedicated line may be worthwhile too, but is not strictly necessary.
This entry was posted on Wednesday, July 27th, 2011 at 5:55 am and is filed under General. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.