using extension cords for charging

[MrFixit]

There is no code issue using a 14-50 receptacle on a 40A circuit. The rationale is compatibility with plug-in EVSE's.
But, you are right... There is a cost differential between the wire sizes, but probably too small to be worth considering.
I see 50' of AWG 8-3 on Amazon for $72. For the same 50' of AWG 6-3, it is $114.

 

[petteyg359]

There is no code issue using a 14-50 receptacle on a 40A circuit. The rationale is compatibility with plug-in EVSE's.

It might be up to code (I kind of doubt it), but if I see a 50 amp receptacle, I expect it to take a 50 amp load. If it doesn't, the installer has effed up.

 

[2002]

In your shoes, I might consider a compromise. You could install a 240V, 20A circuit. This only requires AWG 12 wiring (3 conductors + ground). This wire is no different than what is commonly used in the house (low cost, easy to work with). You would use a 2-pole 20A breaker for this. In the short-term, you would install a standard 120V receptacle (NEMA 5-15/20) and not use the 3rd wire. In the Clarity's future, you could trivially replace the 120V receptacle with a 240V (could use NEMA 14-50) yielding Level 2 capability. The only down-side is that you have limited your Level 2 charging to 16 amps (instead of the 30 amps that the Clarity is capable of). However, even with this limitation, your charge time improves from 12 hours to around 4 hours. You must choose a Level 2 EVSE that allows you to command the 16A limit.

That's an interesting idea, not for my particular situation but I can see it fitting a scenario where someone does not have an outlet close enough to where they park their Clarity to directly plug in, and so they are currently using an extension cord which they want to avoid and they want to install a new dedicated outlet for the Clarity, but keep the cost as low as possible, and also use the existing EVSE as part of keeping the cost down. They could install a dedicated 15 amp circuit which would be the cheapest, but they probably would consider spending a little more for a 20 amp circuit. Then you are offering a third option at slightly more expense which is to run a 240V 20 amp circuit even though it will initially be used 120V with the existing EVSE. This allows at a later date to upgrade the outlet for minimal cost to at least some semblance of Level 2 charging by installing a NEMA 6-20 receptacle.

My situation is similar as far as needing a new dedicated outlet, except I am not fighting to keep costs down I am mainly interested in a one-time installation that will provide for current needs as well as some future proofing. But future proofing within reason, I'm not worried about how I will charge my future 500 mile range Tesla but just reasonable charging which I think a 50 amp circuit should be plenty. I'm lucky also that the new outlet will only be about fifteen feet from the panel so wire cost isn't such a huge issue.

The other difference in my situation is that I have always needed a 120V outlet in that location which is at the back of my garage, among other things to run my two 3 amp fans and my 1200 watt quartz heater all of which are mounted on the back wall. The only outlet currently in the garage is along the side of the garage where the outlet is normally blocked by the car that is parked there, so not a convenient location.

Now along comes the Clarity into my household. As I mentioned the extension cord method is quite workable for now, but it's really time now to install that dedicated outlet that I have always needed in that location. But I also want to future proof for full level 2 charging, and do all of it at the same time while I have the electrician out. Thinking more about it since my original post, it really does seem that I need to install two new dedicated circuits, a 20 amp 120V NEMA 5-20 outlet and a 50 amp 240 volt NEMA 14-50. I will initially only use the 20 amp 120V outlet for charging. Of course once the 14-50 outlet is there staring at me it will be hard not to run out and get a Level 2 cable which I'm sure I will eventually do, however long my willpower holds out although I will probably get a 16 amp EVSE which will be plenty, and since any future electric car I'm sure I will want a 40 amp EVSE to get the full power of the 50 amp outlet. Whenever I do start using the 14-50 outlet for charging I will still have the 120V 20 amp outlet available in that location for other things which is what I want.

 

[MrFixit]

It might be up to code (I kind of doubt it), but if I see a 50 amp receptacle, I expect it to take a 50 amp load. If it doesn't, the installer has effed up.

Rationale:

 

[Wdave]

Well apparently my 12 gauge extension cord that was charging my clarity melted down in the outlet.
Apparently it can't take June heat, so yeah I've got to replace an outlet and still find a way to extend the charging cord to the car.
Any recommendations on beefier extension cords

 

[petteyg359]

Well apparently my 12 gauge extension cord that was charging my clarity melted down in the outlet.
Apparently it can't take June heat, so yeah I've got to replace an outlet and still find a way to extend the charging cord to the car.
Any recommendations on beefier extension cords

Depends how long the cable was. 12 gauge should be okay for a 50' cable. At 100' that should go up to 10 gauge.

 

[Wdave]

Depends how long the cable was. 12 gauge should be okay for a 50' cable. At 100' that should go up to 10 gauge.

It was a 50' 12 gauge cable..
I guess I'll just size down and ensure that the cable is a bit higher quality than the random orange one at home depot, Shame it actually was working quite well until this summer heat finally reared its ugly head here in NYC

 

[petteyg359]

It was a 50' 12 gauge cable..
I guess I'll just size down and ensure that the cable is a bit higher quality than the random orange one at home depot, Shame it actually was working quite well until this summer heat finally reared its ugly head here in NYC

It might've been hanging loose in the socket. Bad connections also increase resistance and heat. Or some moronic roach could've crawled between the prongs and shorted it at the socket. If it was 12 gauge and 50', and it only melted at the socket, it wasn't the cable that was the problem.

 

[2002]

It was a 50' 12 gauge cable..
I guess I'll just size down and ensure that the cable is a bit higher quality than the random orange one at home depot, Shame it actually was working quite well until this summer heat finally reared its ugly head here in NYC

Look for SJTW rating on the cable. Maybe your orange one had that but even so make sure the replacement does. Although 12 gauge in theory is okay, based on your close call you might want to replace with 10 gauge. Also you should inspect the outlet, maybe think about replacing it if possible. Is the cable plugged directly into the outlet or into some type of multi-tap? Best to plug directly into the outlet.

 

[Wdave]

It might've been hanging loose in the socket. Bad connections also increase resistance and heat. Or some moronic roach could've crawled between the prongs and shorted it at the socket. If it was 12 gauge and 50', and it only melted at the socket, it wasn't the cable that was the problem.

You know, I basically tried to have the socket as tight as humanly possible, I kept Bungie cords on both sides of the cable to keep it tight against both the socket, and to reduce the stress on the charger instead of hanging by the prongs on either end.
Probably just a shitty extension cord at the end of the day, thankfully it only melted and didn't cause any other major issues.

 

[Wdave]

Look for SJTW rating on the cable. Maybe your orange one had that but even so make sure the replacement does. Although 12 gauge in theory is okay, based on your close call you might want to replace with 10 gauge. Also you should inspect the outlet, maybe think about replacing it if possible. Is the cable plugged directly into the outlet or into some type of multi-tap? Best to plug directly into the outlet.

Directly into the outlet, It's a bit brown so I'm going to replace it this weekend just in case. Although I think 10 gauge wire is overkill, I feel that it just might be better off going with a 12 gauge 25 foot cable and making that work, instead of having a rolled up 50 foot cable on the wall

 

[2002]

It might've been hanging loose in the socket.

Good point that it is less likely to be the cable. i still think the outlet should maybe be replaced if possible, could be old, could be defective, could have been fine previously but now is damaged.

Directly into the outlet, It's a bit brown so I'm going to replace it this weekend just in case. Although I think 10 gauge wire is overkill, I feel that it just might be better off going with a 12 gauge 25 foot cable and making that work, instead of having a rolled up 50 foot cable on the wall

Yes definitely no longer than you need it. You also will have less voltage drop with a shorter cable although that will likely not make a noticeable difference in charging time. Also if you don't have one, an infrared thermometer gun is pretty inexpensive, approx. $25 and is handy for many things. You can use it to keep tabs on your cable and outlet. If I understood correctly you plan to replace the outlet?

 

[Wdave]

Good point that it is less likely to be the cable. i still think the outlet should maybe be replaced if possible, could be old, could be defective, could have been fine previously but now is damaged.


Yes definitely no longer than you need it. Also if you don't have one, an infrared thermometer gun is pretty inexpensive, approx. $25 and is handy for many things. You can use it to keep tabs on your cable and outlet. If I understood correctly you plan to replace the outlet?

Yessir, Just replace the outlet just to be on the safe side, instead of gamble on the fact that the internals might be ok.
Also on the infared thermometer, I already have one, I just use it to entertain the dog who moonlights as a cat.

 

[MrFixit]

Well apparently my 12 gauge extension cord that was charging my clarity melted down in the outlet.

This is a perfect example of why I recommend avoiding the use of an extension cord in a 'permanent' installation. In all likelihood, the 12 gauge wire was not the culprit. The weak link in an extension cord is at the ends where the wire joins to the plug / receptacle. If the connections are less than perfect, heat will be generated and that can lead to serious trouble. It sounds like you were aware of this, were careful, and didn't do anything 'wrong', but it failed anyway. I think there is a difference between the cheapest 12-gauge extension cord and the more expensive 12 gauge ones. The difference lies in the quality / robustness of the ends.

I would encourage you to seek a way to eliminate the extension cord. If you can't really do that, then don't skimp on the quality. Unfortunately, you can't tell a good one from a bad one visually, and more expensive doesn't necessarily mean better. By all means, don't use an extension cord that is longer than you need (and coil up the excess).

While using an extension cord, make it a point to feel the ends occasionally while operating, and if it feels warm, then don't continue to use it. It is possible you can fend off a failure before it happens. Best bet is to find a better, more permanent solution if you can.

 

[Wdave]

This is a perfect example of why I recommend avoiding the use of an extension cord in a 'permanent' installation. In all likelihood, the 12 gauge wire was not the culprit. The weak link in an extension cord is at the ends where the wire joins to the plug / receptacle. If the connections are less than perfect, heat will be generated and that can lead to serious trouble. It sounds like you were aware of this, were careful, and didn't do anything 'wrong', but it failed anyway. I think there is a difference between the cheapest 12-gauge extension cord and the more expensive 12 gauge ones. The difference lies in the quality / robustness of the ends.

I would encourage you to seek a way to eliminate the extension cord. If you can't really do that, then don't skimp on the quality. Unfortunately, you can't tell a good one from a bad one visually, and more expensive doesn't necessarily mean better. By all means, don't use an extension cord that is longer than you need (and coil up the excess).

While using an extension cord, make it a point to feel the ends occasionally while operating, and if it feels warm, then don't continue to use it. It is possible you can fend off a failure before it happens. Best bet is to find a better, more permanent solution if you can.

No I understand the fact that it's better to have a permanent solution, but a 12 gauge extension cord taught against it's plug is better off than drilling a hole in the wall to pass a wire for a plug on the other side of the garage. If I am going to drill holes at the end of the day I will just run a wire that is capable of powering a 240V outlet instead of just drilling holes for another 110v outlet.

 

[2002]

No I understand the fact that it's better to have a permanent solution, but a 12 gauge extension cord taught against it's plug is better off than drilling a hole in the wall to pass a wire for a plug on the other side of the garage. If I am going to drill holes at the end of the day I will just run a wire that is capable of powering a 240V outlet instead of just drilling holes for another 110v outlet.

Parking outdoors definitely makes permanent installation more of a challenge. If you ever do wind up doing a permanent installation, there are many BEV owners in your situation, you can probably get some good ideas online. Many install a hardwired EVSE outdoors, the power goes inside via conduit. Some install a 240V plug outside, again via conduit. I think I would prefer the hardwired solution for outdoors, but a plug has its advantages and can be done safely with the right weather shielding.

 

[Wdave]

Parking outdoors definitely makes permanent installation more of a challenge. If you ever do wind up doing a permanent installation, there are many BEV owners in your situation, you can probably get some good ideas online. Many install a hardwired EVSE outdoors, the power goes inside via conduit. Some install a 240V plug outside, again via conduit. I think I would prefer the hardwired solution for outdoors, but a plug has its advantages and can be done safely with the right weather shielding.

Well in my instance I have the car in a sort of attached carport next to the house, out of direct sunlight, out of the weather so I thought that having a 12 gauge 50 foot extension cord wouldn't be catastrophic.
So next is a new outlet, a 25 foot 12 gauge extension cord lots of bungee cords to keep everything taught and hope for the best that the next cable ain't made out of cheap Chinese ****

 

[KentuckyKen]

@MrFixit called it. It was the connection between plug and socket, or socket and supply line, and not the cord. A 12 gauge 50 ft extension cord is well within Ampacity limits for a 15 Amp properly wired circuit.
I strongly suggest you replace the outlet with a commercial grade product and do not use the stab connections. Use the old school “wrap the wire around the terminal” connections as they give a much better connection with reduced resistance. And if there is not a GFI on that circuit, replace it with a commercial grade GFI one.
Of course the best long term solution is always to install an outlet close enough to use the OEM EVSE directly plugged in. In any event be sure to protect all connections from water intrusion from rain or blowing rain.
Safety first, foremost, and always.

 

[MPower]

This is the extension cord I got. I thought that it might be useful if I pulled up at a charging station that was ICEd. I used it a my daughter's house when I was there and she kept it for the Prius Plugin that I had given her. It seems to work just fine.

 

[aapitten]

As someone with a degree in electrical engineering I feel like I should make a PSA and comment that a plug being tight means you can plug it in and it takes a little force to get into the plug, and unplug it (also requiring a little force.) The outlet should 'grip' the prongs of the cord. When this happens, it means there is good metal-to-metal contact inside the outlet and thus a good electrical connection. When a plug is loose there is a bad connection that is considered 'high resistance' and causes heating inside the outlet. An example of a common device that intentionally has a (long) high resistance connection inside of it is a toaster.

Taping or tying a cord to an outlet to keep it 'snug' because it is otherwise loose doesn't accomplish the same thing and will cause things to melt, even if the plug is fully inserted.

If your wall plug gets 'loose' the only valid solution is to have the 'female' portion replaced by a qualified person. (I also agree with Ken to avoid the 'push' style connections and use the type that you wrap around a screw or gets clamped in by a screw.

The 'commercial' grade outlets at the big box stores cost a couple bucks more than the $0.59 cheapies, but they will last much longer and give you a much better connection.