using extension cords for charging

Discussion in 'Clarity' started by ProspectiveBuyer, Jun 13, 2018.

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  1. Pushmi-Pullyu

    Pushmi-Pullyu Well-Known Member

    Perhaps extension cords come with warnings not to do any of those things, but in my experience, those things get ignored by the average person in use... or at least by me! I don't recall ever reading those warnings.

    In this case, though, we need to take careful note of such warnings and follow them scrupulously! The risk of fire from continuous high-amp charging is very real, but can be minimized with proper equipment and proper handling. EV owners need to understand the danger and need to take steps to minimize it.

    Also, the charger should not share the circuit with anything else drawing power. The circuit may well be able to handle the amps for the charger alone, but if there are other things plugged into the same circuit, that might overload it.

    [​IMG]
    What not to do: From "National Lampoon's Christmas Vacation"

     
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  3. Viking79

    Viking79 Well-Known Member

    The only reason I recommend 10 (or 12) gauge is for extra derating for if the cord is bundled tightly or if it is sitting in the sun getting hot or for long runs, and they often have better construction (not always). A high quality 14 gauge should be fine ideally, especially since the Clarity is only 10 amps instead of 12.
     
  4. jenniferT

    jenniferT New Member

    usa
    Yes - and - No. First consider the “EVSE” (charging station) as an extension cord of a sort that is specifically designed for cars. Therefore, any time you charge an electric car you’re using a cord that is effectively an extension cord, with EV-related plug on one end, and a couple control wires.
     
  5. DucRider

    DucRider Well-Known Member

    People routinely ignore manufacturer's safety warnings on all kinds of devices. Usually works out fine, but not always.
     
  6. KentuckyKen

    KentuckyKen Well-Known Member

     
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  8. MrFixit

    MrFixit Well-Known Member

    This is a critical point, and the trouble is that almost nobody knows which outlets share a given circuit breaker. I think this is why EVSE's are "supposed to be" on dedicated circuits (no possibility of other loads). Electricians route standard house circuits in all kinds of convoluted ways. A dedicated circuit is best, but almost nobody will adhere to this when using their OEM L1 charger, they will just plug into the nearest outlet.

    Although it is unreasonable to expect people to always adhere to the dedicated outlet rule, I would suggest that everyone use their shared outlets with their eyes open. Take the time to map out which outlets are on the same circuit breaker as your vehicle, and pay attention to what is plugged into those outlets. This can be a little laborious, but simplistically, identify which other outlets share the circuit by turning that circuit breaker off. Then go around with a lamp and find out which other outlets are affected. In some cases, there may be things like ceiling lights with wall switches sharing the same breaker.

    If you do this initially, don't forget going forward and accidentally plug in un-accounted for loads. Maybe something simple like marking all the shared outlets with a piece of red tape could serve as a mental reminder going forward. This is obviously not foolproof, but a little awareness can go a long way.
     
    2002 likes this.
  9. HagerHedgie

    HagerHedgie Member

    I noticed the female end of the 12 gauge extension cord I was using was getting warm to the touch. It was a heavy duty molded plug. I looked inside and the contacts were quite small so I chopped it off and replaced it with an industrial grade plug and now it doesn’t get warm at all. Also, the car now charges about half an hour faster.
    From what I’ve read 12awg or even 14awg is enough to handle the load but if the plug is inadequate a heavy gauge wire isn’t going to help.
     
    KentuckyKen likes this.
  10. 2002

    2002 Well-Known Member

    This is really good advice in fact people should map their entire house, tedious like you said but interesting and you only have to do it once and then it is invaluable anytime you have to do anything electrical, or need to know how many items are running on a circuit. I think a lot of people just go by the cryptic labels on the circuit panel but when you map your house you find all kinds of surprises.

    In my case I already knew that the one outlet in the garage shares a 15 amp circuit with the outdoor GFCI outlets, as well as the basement outlets and ceiling lights. Normally this might present a problem even as a temporary solution, however it works for me because I have a special plug-in rate plan that Georgia Power offers where I can charge at night from 11:00pm to 7:00am for just $0.05/kwh including tax so that is the only time that I charge, I have the schedule set for that time and I never go outside of it because I don't need any more. I rarely use the outdoor GFCI outlets and if I do it's during the day. And my basement is just storage and workshop and I am never down there during those hours. I do have a dehumidifier running down there, I put that on a timer so it doesn't run during those hours.

    I am using a 25ft 12/3 SJTW extension cable to plug into the "essentially dedicated" garage outlet as I described above. So in theory it's all fine but still I consider this temporary, a few months at least until I do something more permanent. I really don't need Level 2, my initial thought is to add a dedicated 20 amp outlet closer to the car so that I won't need an extension cord. Of course since I will already be going to the trouble of having a new circuit installed why not install 240 volt, but even if I go with Level 2 I still want to install a 20 amp outlet in that location because the existing 15 amp outlet is in a bad location behind my other car and I always have to use extension cords for everything in the garage. So my choice is adding a dedicated 20 amp outlet and a dedicated 240 volt outlet, or just a dedicated 20 amp outlet. I will get prices, and yeah in the end I'll probably do both.
     
    Last edited: Jun 6, 2019
    The Gadgeteer likes this.
  11. MrFixit

    MrFixit Well-Known Member

    @2002 - Nice, you are doing this with your eyes open !

    Let me also mention that it is quite possible to share a circuit (even a 15 amp circuit) judiciously.
    I believe the Clarity draws 10 amps with the OEM charger. A 15 amp circuit can support 12 amps 'continuously' with the 80% of maximum rule.

    This theoretically leaves you with 2 'extra' amps. In the old days, you would plug in a couple of 100W incandescent bulbs (1 amp each) and be in trouble. Now, a 60W equivalent LED bulb draws only 7 Watts (0.06 Amps). If you made sure to only use '60W' equivalent LEDs, you could plug in 34 of them before reaching the limit of the circuit !! Just pay close attention to exactly what is plugged in when sharing.
     
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  13. The Gadgeteer

    The Gadgeteer Active Member

    @2002, run the 240 volt outlet then use just one of the 120 volt legs for a 120 volt connection.
     
  14. 2002

    2002 Well-Known Member

    Would that still count as a dedicated 240 volt circuit, or is that not really a requirement for car charging as opposed to say an AC system? I would be adding 240 mainly to future proof, so I would be installing a higher amperage than what Clarity will use. Also would that put any amperage limitations on the 120 volt outlet?
     
  15. The Gadgeteer

    The Gadgeteer Active Member

    A 240 volt, 50 Amp Nema 14-50 outlet is really a 120 & 240 volt outlet.
    So let’s say you run wiring for a 240 volt, 50 Amp Nema 14-50 outlet (common in the EV and RV world), you have to run both 120 volt legs to get 240 volts anyway. At that point using an adapter or having a 20 Amp outlet or two running off the same wiring both is trivial. In other words if you run 240 volt 50 Amp you can downgrade to anything you want that is 120/240 volt as long as you do not try to pull more than 50 amps total. Every other household connection out there is less than 50 Amps.
    So it is a bit of future proofing.
     
  16. 240v installs typically have a dual breaker. The amperage limitation would be that of either leg individually.

    upload_2019-6-7_8-2-39.jpeg

    50A in this case, though 30A is common as well. I think it mostly depends on the gauge of wire run to the outlet.

    As an aside, 120v adapters for most 240v receptacles are readily available, utilizing jut one leg for 120v.
     
  17. petteyg359

    petteyg359 Well-Known Member

    But just like "no extension cords", this is just another idiot-lawsuit-proofing rule. If you've plugged the OEM charger (12 amps) into a 20-amp circuit, there's absolutely nothing wrong with plugging a 3 amp garage box fan into another outlet on the same circuit and using both at the same time.
     
  18. MrFixit

    MrFixit Well-Known Member

    I agree, there is absolutely nothing wrong with your scenario !!

    My only point is that the EVSE is a substantially larger load than most people are used to dealing with, and it is thus worth paying attention to where that circuit runs, and what else is operating on it. Since the OEM charger will only draw 10 amps, you do have some additional capacity available (2 amps on a 15 amp circuit , and 6 amps on a 20 amp circuit).

    As I said, you would likely not need to worry about lights (if they are LED's). But... there are killers that may be commonly found in a garage like electric heaters. Your fan example would be OK but not on a 15 amp circuit. Refrigerators, freezers, dehumidifiers, could be problematic. Multiple other items can add up.

    Once again... OK [in my opinion] to not strictly adhere to the 'dedicated' outlet rule, but just pay some attention to exactly what you have !!
     
  19. MrFixit

    MrFixit Well-Known Member

    This is true in principal, but there are a few things that I find less than desirable.

    Let's assume you installed a 240V 50A circuit with an NEMA 14-50R receptacle. This would be the most 'futureproof'. It would require a 2-pole, 50A circuit breaker with AWG 6 wiring (3 conductors + ground). It would be the most expensive option. For now, you don't want Level 2, so you want to run your existing Level 1 charger somehow. Yes, you can use an 'adapter' to pull out one phase of the 240V. Here is an example of a cable that would do this - https://www.amazon.com/Conntek-Y1450520S-Generator-Y-Adapter-Connectors/dp/B00BHGXYRC

    This would work fine, but I don't like it. First, you spent a lot more money than necessary with the thought that you are 'futureproofing'. By the time that future arrives and you move beyond the Clarity, this could likely be obsolete anyway. If your 'futureproofing' is limited to just the Clarity, then you won't EVER need a 50A circuit. Save some money and install a 40A circuit (smaller wire, easier to work with, a little lower cost). I also don't like it because it introduces an extra plug / socket that dangles (or, you should set up some kind of strain relief). The adapter cables seem overpriced to me. It is possible to make your own, but that doesn't solve the awkwardness. Could you install the heavy circuit and wire in a 120V outlet [for now] instead of the NEMA 14-50? Well, the wire gauge is too thick to wire it directly to the 120V outlet. You would somehow need to attach pigtails (wire nuts), then you have added another vulnerable connection in the path.

    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.

    There are many ways to go, and I know this can be confusing. Most people are at the mercy of the electricians who don't necessarily advocate the most cost effective solutions for what the homeowner feels they need.
     
    Last edited: Jun 7, 2019
  20. DucRider

    DucRider Well-Known Member

    But they are very likely to refuse to implement code violating installs as suggested in many of the previous posts. And yes, not adhering to code can indeed be cheaper - but not sure it would qualify as "cost effective".

    A few examples are putting a 14-50R on a 20A circuit, branching 120V outlets off of a 240V EVSE circuit, etc
     
  21. MrFixit

    MrFixit Well-Known Member

    OK... No intention to start a fight over code compliance.
    Yes, you are correct. An electrician will likely not violate any codes.

    People will always do things on their own without any regard to codes.
    With some discussion about 'reasonable' solutions, maybe it can help steer some away from 'dumb' non-compliant solutions toward 'reasonable' non-compliant ones.

    These are all discussion points, not professional recommendations.

    Your input (never do anything that is not code compliant) is certainly legitimate and valued. Point taken.
     
  22. MrFixit

    MrFixit Well-Known Member

    Here is a slight twist to make the previous suggestion (240V, 20A circuit) fully code compliant...

    When you want to 'upgrade' to 240V, 16A charging, replace the 120V receptacle with a NEMA 6-20R. This is trivial (and fully code compliant).
    A 16A level 2 charger will likely come with this plug type anyway... For example, the Zencar does:
    https://www.amazon.com/Zencar-100-240V-Portable-Electric-Compatible/dp/B075GJK2S9

    For reference, my thought of using the 14-50 (non-code compliant) would enable you to plug in a higher capacity charger (with the 14-50 plug) by commanding it to not exceed the 16A circuit capacity. There may be some controversy as to code compliance of this, but JuiceBox specifically advertises the ability to command lower currents for use on branch circuits with capacities less than the maximum EVSE capability. I suppose you could argue that in this event you should direct wire the EVSE, or change the plug to a compliant 6-20, but to me, a 14-50 used in this way is not a safety concern, just a convenience to avoid direct wiring or changing the plug on the EVSE.
     
  23. petteyg359

    petteyg359 Well-Known Member

    To the contrary...

    1. There is no such thing as a 40 amp receptacle. Why on Earth would you bother to save a few dollars going down 1 gauge of wire to intentionally make your 14-50 receptacle be wired below its rating? You could go with a 14-30, but then you can't use a 32 amp charger, which the Clarity DOES use. Please never ever ever wire a receptacle below what its nameplate says it's supposed to be.

    2. Electrical work hardly ever becomes "obsolete". We transitioned from fuses to breakers a few decades ago, stopped pretending the copper-clad aluminum was at all acceptable, and maybe a few other things.
     

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