New Home Charging Setup

[Rocky_H]

Mobile connector appropriately named as well something to be plugged in or unplugged moved about and taken with you and used here and there as needed. I don't think that it was ever intended that the mobile connector be the primary source for charging.

As someone on this forum frequently says:
"The word MOBILE in the name is a capability, not a requirement."
It is absolutely fine to use the mobile cable as a permanent charging solution.

 

[rjpjnk]

As long as you’re not unplugging if frequently. Those high current 240v sockets may not handle heavy action well.

 

[WADan]

As long as you’re not unplugging if frequently. Those high current 240v sockets may not handle heavy action well.

Not just frequent plugging/unpluging, but the length of charging time could melt cheaply made socket. That’s why Tesla has certain recommended ones!

 

[Johnny Vector]

As long as you’re not unplugging if frequently. Those high current 240v sockets may not handle heavy action well.

Okay, I finally found some data on how many cycles is too many for 14-50 and similar plugs. Still distressingly vague, but here's what I learned.

The relevant standard is UL 498, which costs $1000 so I don't have a copy. According to something I read on the internet (so you know it's true!), when certifying to that standard the plug/receptacle needs to survive 100 plug-unplug cycles at full current without degradation.

Note that this is no different for the 5-15s you have all over your house than for the 14-50 in your garage. Both certified to 100 cycles. The high-current-ness of the plug has no bearing on the standard. There are other categories that require the connector to survive more cycles, such as "hospital grade", but that's not relevant here.

Since the test is done at full current, I would expect the major damage is from arcing. If you only plug and unplug with no power flowing (i.e. remove the charge cable from the car before unplugging the 14-50), it should last a lot longer.

So, is it likely to get worse from repeated cycles just from the mechanical action? I doubt it. Look at how the 120 V 5-15 receptacles fail. You see it all the time in public buildings. Plug into an outlet in an airport to charge up, and the plug just barely stays in. The springs have lost their spring. That kind of failure of spring contacts generally comes from overstressing them. Tugging sideways on the plug, inserting a plug with seriously bent blades, like that. A properly designed contact spring will last until metal fatigue sets in, so it should retain springiness for 10,000 to 100,000 cycles, if all insertions and removals are of properly sized and supported blades.

Now think about a 14-50. Will you be tugging sideways on it, trying to unplug it by pulling on the cable, or bending those honking big blades? Seems unlikely. The larger size makes it much more robust against that kind of damage.

So, yes, the outlets are only certified to 100 cycles, but I would be very surprised if 1000 cycles were ever a problem. I'd get sick of unplugging and replugging that big ol' plug long before then. (I got so sick of doing it 3 or 4 times in a year that I bought a second mobile charger to keep in the car.) Much more important IMO is making sure the wires remain tightly clamped in the back side of the receptacle. Every burned receptacle I've seen or read about is because that connection lost preload. And that's why you want a Bryant/Hubbell receptacle rather than Leviton. The hex screws are far easier to torque properly than the flat-blade screws in the Leviton. And they feel sturdier as well. "You treat 'er right, she'll be with you till the day you die!"