Extension cord

[Abelgoddard]

Had a situation this morning that required me to move my charging FFE. I was at the full length of the EVSE already. Anticipating charging issues, I brought along my 100' 12ga extension cord that I use for my electric mower. So I'm having to use that right now. My question is, what's the ideal solution when you're forced to park too far away from an outlet? What gauge, what length? Is 12ga at 100' ok?

 

[michael]

When asked about extension cords I always tell people:

The electricity came from Hoover Dam (or wherever)
Crossed miles of desert or mountain or whatever
Came along miles of city distribution
Came through your walls

Do you think it cares if it goes through a few feet of extension cord?

The reason people say never to use extension cords is because there some NEC limit on how much cord can be exposed between the wall and the GFCI. But if an extension cord is properly rated, it will work fine. The electrons don't care.

 

[v_traveller]

I've been using this 50ft 12 gauge extension for months, on a nightly basis. No issues. No noticeable heating of the cord or the outlets/plug.

http://www.harborfreight.com/50-ft-12-gauge-tripletap-extension-cord-with-indicator-light-96709.html

Owner's manual is just a CYA, in my opinion.

 

[WattsUp]

Owner's manual is just a CYA, in my opinion.

Probably. For example, to keep folks from using some cheap, under-rated Christmas-tree extension cord, plugged into three 99-cent store power strips, etc.. (You never know what people will do if you don't tell them not to.)

I too, think that a properly-rated, high-quality extension cord is fine. It is important to check the connections for looseness or corrosion that could cause overheating. But, that's true even without an extension cord.

 

[NightHawk]

The way I tell if an extension cord is sufficient for a particular current draw is to use a Kill-A-Watt measuring device.
If the voltage drops below 110V it could be an issue, so thats the number I use to determine if the voltage drop is too much.

 

[EVA]

I use this Coleman Cable 02687 10/3 Vinyl Outdoor Extension Cord with Lighted End, 25-Feet :
http://www.amazon.com/gp/product/B00004SQF1/

Not sure I would use a 100 foot cord, even 12 gauge. Maybe in a pinch, but not regularly.

 

[michael]

In a 110 V 15 A circuit, #12 wire give a 3% voltage drop at 50'
In a 220 V 15 A circuit, #12 wire works out to 100' with a 3% voltage drop

http://www.cerrowire.com/voltage-drop-table

A 3% voltage drop is insignificant, well within the normal range of variation. I charge at both 240 V residential and 208 V commercial outlets, at 14% difference. Works fine at both, just a little faster at 240 than at 208.

Pacific Gas and Electric expects the normal "utilization" voltage to be 120 +6%/-13%
They say the will "usually" supply 120 V +/- 5%

http://www.pge.com/includes/docs/pdfs/mybusiness/customerservice/energystatus/powerquality/voltage_tolerance.pdf

 

[Lithium]

I carry a 25ft 10 gauge extension, lights in both ends, and there is no temp increase to the touch in the extension. The Ford 120V EVSE is of the 16 gauge wire variety, if I remember correctly, and that warms to the touch. Interestingly, I actually felt heat from the face plate of the wall socket at one time. I think using proper gauge and clean/new condition contacts minimizes the heat and the risk.

I got my car in February and used this setup in the snow for about a couple weeks while I bought and hooked up my HCS-40. The extensions melted through the snow.

Also, using a dedicated plug in the house, as opposed to a circuit already loaded up with lights, TV, stereo etc will keep the circuit well below it's spec amp draw.

I think the recommendation not too is to CYA, as a $5 25 ft Christmas tree light 18 gauge extension cord will struggle, aluminum strand, over copper etc.... and heat is the enemy.
H