When I charge my car away from home, sometimes I use the portable 120 volt charge cable that plugs into a normal outlet. At work, we have receptacles mounted a few feet above ground. The charge cable comes stowed and wrapped around a handy coiling device which also lights up during charging. This device hangs directly down when the unit is plugged in, and depending on how much cable I need to unwind to reach the car, weighs around 2-5 pounds.
The question is, is it safe or harmful to hang this mass from the plug? It was designed to work that way, so I have a hard time believing it poses a danger to the receptacle or the cord/plug itself. There is a debate among my fellow electric car drivers about this.
Two of the receptacles recently burned out, so they are attributing it to this, and are insisting we all find a way to support the weight of our chargers elsewhere than from the plug.
Advice?
Best Answer
Generally, cables carrying high current for long periods are expected to be fully unwound from any coiled storage arrangement. This is certainly true of ordinary extension cables.
It is generally not OK to hang heavy loads from power outlet sockets. Regardless of the design of a cable and its storage accessories, the sockets are likely to be designed to carry the weight of the plug and sufficient cable to reach the ground. I'd expect the designers to make provision for people tripping over the cables, pulling on them and driving off without detaching them. However it is likely that the intent is to reduce the likelihood that any consequential mechanical damage to the socket subsequently exposes people to an electrical hazard.
For $72 you can obtain the J1772 standard and find out if it specifies the mechanical strain that the socket should be designed to withstand. In the EU you'd check standard IEC 62196‑2.