Using an Extension Cord With The FFE

[marcham93]

Hello, all!

I just signed the papers on a 2017 FFE lease and I'm super excited. I have a few questions for those of you knowledgable owners out there. Right now I have a 120v outlet outside by the garage, but the issue is that the included 18 foot cord wouldn't reach.

Would I be able to use a heavy duty 10 gauge extension wire to make it out to the driveway? I know that extension cords aren't recommended, but if I use one that could handle the power would that be fine?

Thanks for the advice, all.

 

[NightHawk]

Depends on the length you need I guess, but I have used about a 10foot 12ga extension cord successfully with the Ford 120v charging unit on my 2014 FFE many times away from home.

 

[marcham93]

Seems to be a sensitive topic with some and a 'no big deal' conversation with others.

Most people seem to do fine with a good extension cord, so I'm hoping I won't run into any trouble with a heavy duty cord.

I assume that Ford discourages against it to prevent people from using old extension cords they have laying around.

 

[henryfocus]

Completely unscientific evidence here: I had a situation once where I needed to charge with a 50ft rather thin extension cord otherwise I wasn't going anywhere. The cord became significantly warm to the touch. Luckily it was a cold out.

 

[michael]

It will absolutely work if the cord is properly rated for the current drawn.

The reason manufacturers always say not to use an extension cord is because you are not supposed to do so. Article 625 of the NEC sets a maximum distance of 12" for the cord from the outlet to the EVSE protective equipment.

This doesn't mean it wont work. It just means you are not supposed to do so. The electrons don't care.

 

[marcham93]

The reason manufacturers always say not to use an extension cord is because you are not supposed to do so. Article 625 of the NEC sets a maximum distance of 12" for the cord from the outlet to the EVSE protective equipment.

Ah, it is a law. Interesting to see the source of the warning.

I figured I'd be safe as long as the cable was properly rated.

P.S. - What do you guys think of this cable from Goodyear? It seems like it would be excellent for what I need; easily retractable to the end of the driveway and back if needed. It is heavy duty rated 12 gauge and designed for commercial and industrial use.

https://www.amazon.com/gp/product/B01GFA3636/ref=abs_brd_tag_dp?smid=ATVPDKIKX0DER

 

[NightHawk]

The reason manufacturers always say not to use an extension cord is because you are not supposed to do so. Article 625 of the NEC sets a maximum distance of 12" for the cord from the outlet to the EVSE protective equipment.

Ah, it is a law. Interesting to see the source of the warning.

I figured I'd be safe as long as the cable was properly rated.

P.S. - What do you guys think of this cable from Goodyear? It seems like it would be excellent for what I need; easily retractable to the end of the driveway and back if needed. It is heavy duty rated 12 gauge and designed for commercial and industrial use.

https://www.amazon.com/gp/product/B01GFA3636/ref=abs_brd_tag_dp?smid=ATVPDKIKX0DER

That listing says "40 ft, 14AWG"
40ft might be pushing it, I'd recommend the smallest length that will work for you and 12AWG would be better.

Here is one that works for me, I use a separate cord reel with it:
https://www.amazon.com/gp/product/B002HWRS7W/ref=oh_aui_detailpage_o05_s00?ie=UTF8&psc=1

 

[marcham93]

Awesome, thanks. I saw that one before and it would be perfect. Like you said, I can always purchase the reel separately.

UPDATE: Just to keep you guys updated on my research. It seems that a cord of around 20-feet pulling up to 16 amps should be 8-guage. As a result, I think I will be going with this cable linked below. I want to play it safe and this seems to be the best option.

https://www.amazon.com/Gauge-Welding-Extension-40A-250V-Lighted/dp/B06W563YSZ/

Source: http://www.amplepower.com/primer/gauge/

 

[EVA]

The one you linked to at Amazon is pretty similar to the one I carry in my Tesla - have used it many times at hotels and other 120V outlets to charge the car overnight. You got the kind of overkill gauge to be safe.

This is the one I used - I liked the yellow wire and the lighted ends.

https://www.amazon.com/gp/product/B00004SQF1/

The one you linked to is 8 gauge, and is slightly cheaper than the one I use at 10 gauge. The only downside to the heavier gauge, it might not bend as easily and will be heavier.

As an aside, Tesla's charging circuit is really critical of the power. It will reduce amperage and stop charging if it senses any slight changes. I've never had a problem with the extension cord and reduced amperage or turning off charging the car.

 

[triangles]

Using an extension cord can be safe and it can be a fire hazard. If the ends of the cord become dirty or corroded they will have resistance which will generate heat. The higher the current and/or resistance the higher the heat. If you want to get technical about the ampacity of the wire you intend to use Ugly's Electrical Reference is a great reference with a lot of no BS info to help you determine what gauge extension wire will be safe for your situation. I provided a link to amazon but I think some of the big box hardware stores like home depot carry it too. I realize it's not directly applicable to an extension cord with the FFE but when I used to work with industrial equipment we had to pull the coiled power cords out of their box for the servo motors while testing/debugging. If we didn't the powers cords would over heat, melt, and short out. While not likely, I do think it would be possible to have a scenario where an extension cord coiled/balled up and enclosed such that it cannot transfer heat to the surrounding air could get hot enough to melt.

Probably the best thing you can do to avoid a problem with an extension cord is to not use one. If that's not an option, this is a place where you want to spend more money for a quality cord and get the lowest gauge (thickest, 10ga min.) wire you can. Don't buy a cord any longer than you absolutely need. To be extra safe feel the cord near the ends after plugging in. If they quickly become hot, unplug from the car asap and don't use that cord. You probably should also periodically check the cord for heat while charging. It's not unusual for the cord to become warm just make sure it doesn't get hot. Yes I know that last part is vague but this is where you have to use your grey matter to decide what is and what isn't acceptable when you are using your laser precision temperature measurement devices at the end of your arms <sarcasm> Suffice it to say, slightly warm = ok and hot = bad!

From my personal experiences about a year ago, I used the book mentioned above as a guide to determine kind of extension cord I needed. I determined a 10ga 40' extension cord would be safe for me. I don't remember the exact details but I think a 12ga would have been sufficient but I went a size or two thicker than what I needed for an added margin of safety. I've only used it a hand full of times and have had no issues. I've never need anywhere near the full 40' but made sure the coiled up remaining wire was spread out enough to dissipate heat should it get hot. As an added safe guard and since charging time wasn't an issue, I set my EVSE to charge at 8A instead of 12A that the included Ford EVSE will pull. Oh yeah, In case you're wondering, you won't find a cord rated higher than 15A even though the wires inside may be capable of higher current simply because the connectors on the ends are only rated at 15A and also the outlets are 15A max as well.

I can tell you from experience to avoid the Harbor Freight cheapies unless you want to start a fire. I had an old cord of unknown gauge that I got from harbor freight years ago. I didn't expect it to work but I wanted to experiment and see what would happen. It was a short experiment as almost immediately the cord near the ends became too hot to touch. Had I been stupid enough to try a full charge, I likely would have burned down my house. This is why they don't want you to use an extension cord since inevitably some idiot would burn their house down and blame Ford for their own stupidity.

 

[EVA]

Best advice ever Triangles. Can't over emphasize uncoiling the cord. Never use an extension cord that is wound up in a coil. It will overheat. No coils in a bucket, no roll up device, no coil just sitting on the floor.

 

[amped]

https://www.amazon.com/Gauge-Welding-Extension-40A-250V-Lighted/dp/B06W563YSZ/

Source: http://www.amplepower.com/primer/gauge/

This one seems to be intended for a 50 amp/240v circuit - it has NEMA 6-50 connectors. I was under the impression that you were talking about extending from a standard 15A/120v receptacle, in which case you would need to change out the plug/connectors. I'm not sure how feasible this would be with such heavy gauge wire and you would also have to worry about properly weatherizing it.

Your link on sizing is for <3% voltage drop on a 12 volt circuit and greatly overestimates what would be needed for 120v. Also, IIRC, the FFE EV onboard charger is not exquisitely sensitive to voltage and can accept input from ~100 to ~260 volts so significantly greater than a 3% voltage drop could be tolerated. You just need to worry about sizing the cord thick enough to avoid overheating (and, as others have pointed out, keep it uncoiled during charging). I think 12 gauge should be more than adequate for 20ft.

 

[EVA]

Wow, this just gets more complicated as we go.

Amped is absolutely correct Marcham93 - you picked the wrong extension cord. That one will never plug into a 110V outlet. It is a NEMA 6-50 plug that looks a lot like a regular old three prong plug (that's why I thought the cord would work, the plug looked correct) - but is way bigger.

What you need to buy is a 120V extension cord at least 10 gauge for all three conductors. This one fills the bill. It isn't necessarily special, it just works.
https://www.amazon.com/gp/product/B00004SQF1/

Under NO circumstances should you use that Goodyear reel cord you linked to earlier. That is a fire waiting to happen unless you unwound the whole cord at every use. 40 feet is probably too long anyway, and the gauge is on the light side.

 

[triangles]

:lol: That cord he linked is what I use for my L2 EVSE except the 25' version. 8ga was a little lighter than what I wanted but the cord is supposedly rated for 40A. It never gets even warm with the 30ish amps my FFE pulls.

 

[shniestEV]

I use an extension cord quite frequently lately. At my work we have standard chargepoint parking spots but they are a good 10-15 minute walk from my office. I found our parking garage beside the office is equipped with regular 120v outlets near some parking stalls. I started using these since my commute to work only uses about 30km of battery I can charge with these stalls for about 6 hours and be able to leave work with a full battery so no need to park so far away to use the chargepoint stations.

I haven't had any issues and started using an extension cord since the cold weather began in December. Unfortunately there is a cage blocking the plug so to make life easier I run an extension cord through the cage to avoid having to set the convenience cord up every day and also the risk of leaving it open in the public. My luck would have it that I found a heavy duty extension cord in the garage which i noticed had been there for almost a year so figured it belonged to nobody or someone forgot about it. I leave this here permanently i'm surprised it hasn't be stolen yet!

So almost everyday (if i get in early enough to park in one of 3 stalls the cord reaches) I will use the extension cord with my ford convenience cord evse (120v).
Its about a 50ft cord but is construction heavy duty i'll have to see if the gauge is labelled but figured its probably around 8-10 gauge from experience.

It doesn't heat up the cord and haven't noticed any type of issues.