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Re: Standard Extension Cord Charging

Posted: Sun Apr 02, 2017 1:49 pm
by LeftieBiker
LEAF draws 1440 watts. No one should use a L1 EVSE on even a 12G Extension Cord or anything other than a dedicated proper 120V outlet. Any attempt to imply this is remotely safe is reckless IMO and very irresponsible. There are so many more variables to consider in the real world and it's simply a bad practice to justify even indirectly.
This assumes the worst 12 gauge extension cord, with the alternative being the best 120 volt wall outlet. A genuinely good 12 gauge cord plugged into a non-worn outlet will barely get warm. So rather than tell people not to do things they will do anyway, I suggest you tell them, as I do, to make sure the cord and outlet are both high quality and in excellent shape.

Re: Standard Extension Cord Charging

Posted: Mon Apr 03, 2017 7:13 am
by EVDRIVER
LeftieBiker wrote:
LEAF draws 1440 watts. No one should use a L1 EVSE on even a 12G Extension Cord or anything other than a dedicated proper 120V outlet. Any attempt to imply this is remotely safe is reckless IMO and very irresponsible. There are so many more variables to consider in the real world and it's simply a bad practice to justify even indirectly.
This assumes the worst 12 gauge extension cord, with the alternative being the best 120 volt wall outlet. A genuinely good 12 gauge cord plugged into a non-worn outlet will barely get warm. So rather than tell people not to do things they will do anyway, I suggest you tell them, as I do, to make sure the cord and outlet are both high quality and in excellent shape.
Because most people don't know what a "good outlet" is nor a proper 12G cord. Many LEAF owners have have had complete melting of the ends of "good" new extension cords. Reckless is recommending long 14G, 18G and other cords of very long lengths. Many of the "good" extension cords sold on Amazon are junk and have poor terminations that fail and melt.

Re: Standard Extension Cord Charging

Posted: Mon Apr 03, 2017 9:34 am
by desiv
EVDRIVER wrote: Many LEAF owners have have had complete melting of the ends of "good" new extension cords.
So, just wondering..
How many is "many" in this case?

Thanx,

desiv

Re: Standard Extension Cord Charging

Posted: Mon Apr 03, 2017 10:15 am
by EVDRIVER
desiv wrote:
EVDRIVER wrote: Many LEAF owners have have had complete melting of the ends of "good" new extension cords.
So, just wondering..
How many is "many" in this case?

Thanx,

desiv

I know of at least 20 plus first hand and this is the type of thing that many consumers don't report. 120V charging is much higher risk and using an extension increases that risk dramatically. Since this is continuous load use there is no point in taking a risk. At least get a 10G or heavier well built extension if you are going down this route. Best bet is a quality cord with properly welded ends no screw connections or cheap cords from China with high resistance poor terminations.

Re: Standard Extension Cord Charging

Posted: Mon Apr 03, 2017 10:58 am
by desiv
EVDRIVER wrote:I know of at least 20 plus first hand and this is the type of thing that many consumers don't report.
Doesn't sound like too many to me, but different perspectives.. ;-)
Also, I'm a cynic..
Nothing personal, but in the I.T. field, it's not umcommon to have people report that they know of at least 20 users that are having the same problem as they are, only to find out that the number is actually much less...
Not saying that it's the same with you.. Just that I'm a bit biased in that way.. ;-)

After all, I've read that 87.4% of statistics are made up on the spot.. :D

Still, it is good for people to be aware of possible danger..
These things draw a lot of power.
I always tell people, imagine you are plugging in a standalone electric heater and leaving it on for hours..
Be safe!! ;-)

desiv

Re: Standard Extension Cord Charging

Posted: Mon Apr 03, 2017 11:40 am
by jlv
I've read (here) that the Nissan trickle charger has a thermal overload protection (to detect the outlet heating up), and using an extension cord thwarts that protection. Is that true?

Re: Standard Extension Cord Charging

Posted: Mon Apr 03, 2017 11:53 am
by EVDRIVER
jlv wrote:I've read (here) that the Nissan trickle charger has a thermal overload protection (to detect the outlet heating up), and using an extension cord thwarts that protection. Is that true?

It will cause it to drop the amp level on the EVSE when it heats.

Re: Standard Extension Cord Charging

Posted: Mon Apr 03, 2017 4:37 pm
by baustin
jlv wrote:I've read (here) that the Nissan trickle charger has a thermal overload protection (to detect the outlet heating up), and using an extension cord thwarts that protection. Is that true?
The thermal sensor is inside the plug. If connected directly to an outlet, it will sense the outlet heating up. If connected to an extension cord, it will only sense if the end of the cord is heating up. I believe, somewhere in the manuals, Nissan says not to use an extension cord.

Re: Standard Extension Cord Charging

Posted: Tue Apr 04, 2017 8:27 am
by Bob
For anyone reading this who is considering using an extension cord, you can do a few simple things and make yourself much safer.

1) Start with a new extension cord with large gauge wire. Lower numbers mean larger wire. Definitely do NOT use 14 gauge wire. 12 gauge is better and 10 gauge is the best you'll find in a common extension cord.

2) After charging for ten minutes, test the setup. Run your hand over the plug, jack, and wire ends. Do you sense any hot spots? A slight sense of warmth is normal and expected (perhaps 5 degrees hotter than outside air) but if it feels 20 degrees hotter than outside air, don't continue.

3) Be gentle with your extension cord. It will wear out quickly if abused. Don't flex it too much. Don't coil it into too small of a circle. Treat the wire at the plug and jack carefully. This is the most frequent point of failure. People will bend the wire right at the plug and jack with a very tight radius and cause the multi-strand wire inside to break at the point where it is rigidly connected to the plug and jack.

There is something unique about 120V EV charging - it is used for very long periods of time at full current, unattended. If there is a weak point in an EV charging cable, that point can heat up over time, leading to a further increase in resistance, leading to more heat, leading to physical motion of the wire causing conductors to separate, leading to arcing and fire. The risk is real and the consequences are potential fire plus potential loss of life. Block heaters have some of the same issues, but the higher-power block heaters have thermostats so they don't run full current continuously.

Disclaimer: I am not an electrician. I am not a licensed engineer. This is just common sense advice, not a guarantee or professional opinion. If you have any doubts, follow the instructions in the manual and don't use an extension cord.

Bob

Re: Standard Extension Cord Charging

Posted: Wed Apr 05, 2017 12:48 pm
by JohnKuthe
Bob wrote:For anyone reading this who is considering using an extension cord, you can do a few simple things and make yourself much safer.

1) Start with a new extension cord with large gauge wire. Lower numbers mean larger wire. Definitely do NOT use 14 gauge wire. 12 gauge is better and 10 gauge is the best you'll find in a common extension cord.

2) After charging for ten minutes, test the setup. Run your hand over the plug, jack, and wire ends. Do you sense any hot spots? A slight sense of warmth is normal and expected (perhaps 5 degrees hotter than outside air) but if it feels 20 degrees hotter than outside air, don't continue.

3) Be gentle with your extension cord. It will wear out quickly if abused. Don't flex it too much. Don't coil it into too small of a circle. Treat the wire at the plug and jack carefully. This is the most frequent point of failure. People will bend the wire right at the plug and jack with a very tight radius and cause the multi-strand wire inside to break at the point where it is rigidly connected to the plug and jack.

There is something unique about 120V EV charging - it is used for very long periods of time at full current, unattended. If there is a weak point in an EV charging cable, that point can heat up over time, leading to a further increase in resistance, leading to more heat, leading to physical motion of the wire causing conductors to separate, leading to arcing and fire. The risk is real and the consequences are potential fire plus potential loss of life. Block heaters have some of the same issues, but the higher-power block heaters have thermostats so they don't run full current continuously.

Disclaimer: I am not an electrician. I am not a licensed engineer. This is just common sense advice, not a guarantee or professional opinion. If you have any doubts, follow the instructions in the manual and don't use an extension cord.

Bob
All good advice. I'm not a licensed engineer, just a EE by degree, and the heavier a wire gage the better! Charging electric cars is a "high power" application, that's why I'm getting a 240VAC line run for it. And until then I'm using a 150FT early 1980's Craftsman 3 prong extension cord that I also use to mow, trim and leaf blow (all corded electric!) I can't remember it;s wire gage but I think it's 14 gage. Works wonderfully! Back when Craftsman was the GOOD STUFF! :-)

John Kuthe...