For Added Safety, Tesla Ships Replacement Power Adapters To Its Model S Customers

If there’s one thing  Tesla Motors [NASDAQ:TSLA] takes seriously, it’s the safety of its cars and their customers. That’s a reputation the Californian automaker has worked hard to earn, and will do anything to uphold.


As an added measure, Tesla is sending all of its UMC-owning Model S customers a replacement NEMA 14-50 adapter

Which is why Tesla Motors has announced this afternoon that it intends to send all of its Model S customers with a Universal Mobile Connector charging unit an improved wall adapter designed to act as an extra layer of protection between a standard 240-volt wall outlet, the electrical circuits the car is plugged into, and the car itself.

The decision, announced publicly today by Tesla via an official post on its website, will see the company mail replacement Tesla Universal Mobile Connector charge adapters to each and every Model S customer who opted to buy a Universal Mobile Connector to charge their car with.

The adapter comes as part of the Mobile Connector Bundle, a $650 option available for any Model S.

The move was prompted after several Model S owners complained that they had noticed the connection between their car’s wall charger and the wall adaptor it was plugged into had started to overheat. In once instance reported on the Tesla Motors Club forum from October last year, an owner said he saw ‘plumes of smoke’ rising from the Tesla NEMA 14-50 plug connecting his Universal Mobile Connector to a NEMA 14-50 plug in his garage. The car itself was continuing to charge.

Then in November, a garage fire in Irvine California where a Model S was charging via a Universal Mobile Connector lead Orange County Fire Department to question if faulty wiring had caused the electrical wiring in the house to overheat and catch fire.

In total more than six different Model S Universal Mobile Connectors have been publicly reported on the Tesla Motors Club Forum as having overheated in some way whilst charging a Model S. In one case last month, an owner claimed he burned his hand trying to remove an overheated  adaptor from the Universal Mobile Connector after smelling burnt plastic.

At the end of last year, Tesla pushed an over-the-air update to all of its Model S cars designed to automatically reduce the charging current by twenty-five percent if it detected the tell-tale drop in voltage that often signals a high-resistance wiring fault — or in other words, overheated wiring.

In its official statement, which we’ll reproduce below, Tesla has said that the upgraded NEMA 14-50 to Universal Mobile Connector adapters have been redesigned to include a thermal fuse which will break the circuit if the wall socket or the NEMA plug it is connected to overheats for any reason.


Last month's Model S software has already added one layer of protection: the adaptor is an extra layer

Last month’s Model S software has already added one layer of protection: the adaptor is an extra layer

This will help protect both the circuit the car is plugged into, but also the car itself, and has been implemented by Tesla to “Provide another layer of assurance to Model S customers” even though Tesla believes the software update released last month already “fully addresses any potential risks.”

Nevertheless, we think Tesla’s decision to mail upgraded NEMA 14-50 adapters to all Model S customers with a Universal Mobile Connector charge unit is a smart move as it not only helps ensure there are no more issues of overheating but that Tesla is seen by its (usually very vocal) customers to be doing everything it can to ensure there are no overheating risks moving forward.

As you might expect too, Tesla has informed the NHTSA of its decision to upgrade the adapters, something it is calling a ‘proactive measure.’

If you’re a Model S owner and have a NEMA 14-50 Universal Mobile Connector adapter unit we’d be interested to hear from you. Have you noticed any problems with the old design? Does the new unit look the same as the old one? And what’s your response to Tesla’s quick response to the problem?

Leave your thoughts in the Comments below.


Press release from Tesla Motors: 


PALO ALTO, Calif. – A variety of factors such as corrosion, physical damage to receptacles, or inappropriate wiring or installation of electrical outlets can cause higher than normal electrical resistance when using the Universal Mobile Connector (“UMC”) NEMA 14-50 adapters to charge Tesla Model S vehicles. When charging, higher than normal electrical resistance connections to external energy sources may cause excessive heating of the adapter. In December 2013, Tesla released an over-the-air software update to address this issue, enabling the Model S onboard charging system to automatically reduce the charging current by 25 percent if it detects unexpected fluctuations in the input power to the vehicle. This fully addresses the issue by substantially reducing the heat generated in any high resistance connections outside the vehicle. This update increases robustness and safety considerably in the unlikely event that a home wiring system, receptacle, adapter or cord is unable to meet its rated current capacity.

Because this was an over-the-air update, customers can confirm receipt without having to bring their vehicles into a Tesla Service Center or other location by simply tapping on the 17” touchscreen and verifying that their Model S is running software version 5.8.4 or later. Any vehicle that is not within range of the wireless network or is not remotely accessible for any other reason can have the update installed through Tesla authorized Service Centers or Tesla Rangers.

Tesla believes that this software update fully addresses any potential risks. However, to provide another layer of assurance to Model S customers using the 14-50 socket, we have designed an improved wall adapter with a thermal fuse. Even if the circuit breakers on the house side and car side don’t trip, the thermal fuse will prevent current from flowing if the wall socket region heats up for any reason. Although we do not believe the improved adapter is required to address the issue, we are taking this step as part of our commitment to full customer satisfaction. We will provide this upgraded adapter to existing and new customers free of charge starting in a few weeks.

In addition, Tesla has informed the National Highway Traffic Safety Administration of these proactive measures.


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