connecting EVSE to dryer outlet ?

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RustyShackleford

Well-known member
Joined
Jun 24, 2019
Messages
157
Location
central NC
My 2018 Leaf has the dual-voltage EVSE cord, which can plug into a 120v outlet, or a 240v outlet (with 14-50P plug). Is it reasonable/legal/safe to plug the EVSE (in 240v configuration) into a 30amp dryer outlet ? The dryer outlet has a 14-30R receptacle and is protected by a two-pole 30amp breaker. I imagine making a 50ft extension cord with 14-30P plug at one end and 14-50R receptacle at the other end. Would use either 8-4 SJOOW cord, or it appears to be cheaper to buy a 50amp 14-50 extension cord and replace the plug with a 14-30.
 
Some searching here suggests that it's considered unsafe to plug the EVSE into a 30amp dryer outlet. I'm a bit confused about that, because if circuit is protected by 30amp OCPD (breaker) and my proposed cord has terminals and wire rated for 30amps, isn't that safe ? Is the issue "continuous loads" ?
 
The stock L1/L2 120/240 volt EVSE has a NEMA 14-50 plug for a reason.

With 6.6 kW OBC, that means 6600 watts / 240 volts = 27.5 amps. It is unsafe to have a 27.5 amp continuous load on a 30 amp circuit. 24 amps is the max safe continuous load. You need an L2 EVSE that will pull no more than 24 amps if you want to use it on a 30 amp circuit.

This has been discussed many times. Google for site:mynissanleaf.com 24 amp dryer outlet.
 
There is some debate as to whether it is safe to use that combination for a hour or two only (the 80% use rule apparently applies to use for three hours or more), but you definitely can't use it for longer, and probably shouldn't do it at all. You should also consider how old that dryer wiring is.
 
So short sighted of Nissan to not include a 24 Amp charging setting in the car. <<sigh>>

I wonder what 3rd party solutions are out there. Adding a 1300 mOhm resistor to the circuit would do the trick
 
Check the drier plug and compare it to the EVSE NEMA 14-50. They may be slightly different.

The issue is heat. The wiring to the drier plug is not suitable for the car loads. Using it drier will probably blow the breaker.
 
SageBrush said:
So short sighted of Nissan to not include a 24 Amp charging setting in the car. <<sigh>>
Many other BEVs and PHEVs provide no setting. It's not great idea to include it as it creates confusion and can encourage people to use dodgy setups. Imagine if they had Federal Pacific or Zinsco breakers that tend to not trip in the event of overload and then do stuff like the OP wants to do.

An EVSE should be installed so that it emits the proper pilot signal duty cycle (https://openev.freshdesk.com/support/solutions/articles/6000052074-basics-of-sae-j1772) corresponding to the max allowed continuous load for that circuit.

What is short-sighted is that Nissan doesn't provide an EVSE like https://shop.tesla.com/product/mobile-connector and adapters like https://shop.tesla.com/product/gen-2-nema-adapters which cause the EVSE to adjust its pilot signal depending on which adapter is attached. Tesla's been doing this since for ages with their gen 1 mobile connector which has different adapters.
 
RustyShackleford said:
My 2018 Leaf has the dual-voltage EVSE cord, which can plug into a 120v outlet, or a 240v outlet (with 14-50P plug). Is it reasonable/legal/safe to plug the EVSE (in 240v configuration) into a 30amp dryer outlet ? The dryer outlet has a 14-30R receptacle and is protected by a two-pole 30amp breaker.
I charged my Leaf like this for 10 years--with a 20A version of the (old) EVSE.

RustyShackleford said:
I imagine making a 50ft extension cord with 14-30P plug at one end and 14-50R receptacle at the other end. Would use either 8-4 SJOOW cord, or it appears to be cheaper to buy a 50amp 14-50 extension cord and replace the plug with a 14-30.
I essentially constructed a similar "physical" adapter, but I do not recommend running 240v over a 50 ft extension cord; not even sure I would recommend half that distance.
 
cwerdna said:
What is short-sighted is that Nissan doesn't provide an EVSE like https://shop.tesla.com/product/mobile-connector and adapters like https://shop.tesla.com/product/gen-2-nema-adapters which cause the EVSE to adjust its pilot signal depending on which adapter is attached. Tesla's been doing this since for ages with their gen 1 mobile connector which has different adapters.

It is a nifty solution for sure. So much so, that even though we now only drive a CCS car, I bought the Tesla EVSE, the Tesla adapter set, and a Tesla -> J1772 adapter as my do all, connect to anything L2 kit.

IIRC, the total kit added up to
EVSE - $200
Adapter bundle - $200
J adapter - $150

The funny thing is, even though I know Tesla pretty in depth, I didn't consider this package for our CCS car. The Bolt forum people have figured it out. I gather it is their preferred L2 solution, unless they choose the cheap and crappy generic Chinese approach.
 
RustyShackleford said:
My 2018 Leaf has the dual-voltage EVSE cord, which can plug into a 120v outlet, or a 240v outlet (with 14-50P plug). Is it reasonable/legal/safe to plug the EVSE (in 240v configuration) into a 30amp dryer outlet ? The dryer outlet has a 14-30R receptacle and is protected by a two-pole 30amp breaker. I imagine making a 50ft extension cord with 14-30P plug at one end and 14-50R receptacle at the other end. Would use either 8-4 SJOOW cord, or it appears to be cheaper to buy a 50amp 14-50 extension cord and replace the plug with a 14-30.

Not at all. You need a lower rated EVSE. I have a 24 amp Clipper Creek sharing my dryer outlet. Since it runs a 5.88 KW, its fine and within the limitations of the 30 amp outlet.
 
DaveinOlyWA said:
I have a 24 amp Clipper Creek sharing my dryer outlet.
To be clear (and I think it also came up earlier) - I am NOT planning to share this with the dryer, in the sense I'd run both at once. It's a vacation house, gonna be an infrequent thing to charge the car there. I'd unplug the dryer and plug the proposed extension cord into it.
 
Anyhow, looking like it's a non-starter to plug the Leaf's EVSE into a 30amp outlet. Unless I'm on my honor to unplug it after 2:59 hours so it's not a continuous load. In which case, why bother ? I'll just charge it in 120v mode.

Or forget all this and install a dedicated Level-2 charger on its own 40- or 50-amp circuit. Could be a draw in renting the place !
 
RustyShackleford said:
DaveinOlyWA said:
I have a 24 amp Clipper Creek sharing my dryer outlet.
To be clear (and I think it also came up earlier) - I am NOT planning to share this with the dryer, in the sense I'd run both at once. It's a vacation house, gonna be an infrequent thing to charge the car there. I'd unplug the dryer and plug the proposed extension cord into it.

Reiterating the obvious. I tried to do both. Lasted about 3 minutes before the breaker tripped. I did it to make sure the breaker knew how to do its job.

But doesn't change the fact that a 24 amp EVSE is the MAXIMUM you can use "legally"

Someone mentioned a 3 hour rule or something... Yeah, not something I would try.
 
FWIW, I bought a Zencar 32A adjustable, portable EVSE similar to this one:

https://www.zencar.net/product/volt-evse-10a-16a-saej1772-nema-14-50/

It's CE, TUV and UL certified. Not sure what they cost now, but very likely less than $400 USD.
 
alozzy said:
FWIW, I bought a Zencar 32A adjustable, portable EVSE similar to this one:

https://www.zencar.net/product/volt-evse-10a-16a-saej1772-nema-14-50/
This looks like it: https://www.amazon.com/Charger-Electric-Vehicle-Charging-Station/dp/B08FM825WX?th=1

Still need to build an extension cord with 14-30P (to plug into the dryer outlet) and 14-50R (for the EVSE to plug into). Or, buy an off-the-shelf 30amp 14-30 extension cord and an EVSE with a 14-30P plug (that maxes out at 24 amps) such as: https://www.splitvolt.com/product/portable-ev-charger-nema-14-30-24-amp/

One oddity: the off-the-shelf 30amp cords use 10awg wire, yet it appears that 10/4 portable power cord is rated at 25amps; not sure how they get around that. As far as voltage drop, I think 10awg is fine, it's about 1-ohm per 1000 ft, so figure the extension cord would drop 2.5v or so.

Looks like it might be possible to recoup most of the cost of the adjustable EVSE by selling the OEM: https://www.ebay.com/itm/115187504196. I don't need it, since I installed a Level-2 charging station at home (Clipper Creek hardwired with a dedicated 50amp circuit).
 
RustyShackleford said:
One oddity: the off-the-shelf 30amp cords use 10awg wire, yet it appears that 10/4 portable power cord is rated at 25amps; not sure how they get around that.
Not super familiar with NEC Table 400.5(A)(1) on the ampacity of cords, but it distinguishes between the case of 2 current carrying conductors and 3 current carrying conductors.

If you were using your 10/4 (which counts the EGC) for 3 phase power, then that would definitely be 3 current carrying conductors, and the ampacity would be limited to 25A. However, on a 120/240V system where one conductor is the neutral and only carries the current imbalance, then the neutral is generally omitted from the current carrying conductor count, so it would be 2 current carrying conductors, and the ampacity is 30A.

Regardless, as an EVSE is a straight 240V only load, it's definitely 2 current carrying conductors, and the #10 cords would have an ampacity of 30A.

Cheers, Wayne
 
If you order directly from Zencar directly, you can ask them to put a 14-30P plug on the end of the EVSE and they will put a longer cord on the EVSE too, for an upcharge of course.

It used to be cheaper to buy direct, although you will have to pay for shipping. Not sure if they still sell direct though, but worth a try...
 
wwhitney said:
RustyShackleford said:
One oddity: the off-the-shelf 30amp cords use 10awg wire, yet it appears that 10/4 portable power cord is rated at 25amps; not sure how they get around that.
Not super familiar with NEC Table 400.5(A)(1) on the ampacity of cords, but it distinguishes between the case of 2 current carrying conductors and 3 current carrying conductors.

If you were using your 10/4 (which counts the EGC) for 3 phase power, then that would definitely be 3 current carrying conductors, and the ampacity would be limited to 25A. However, on a 120/240V system where one conductor is the neutral and only carries the current imbalance, then the neutral is generally omitted from the current carrying conductor count, so it would be 2 current carrying conductors, and the ampacity is 30A.

Regardless, as an EVSE is a straight 240V only load, it's definitely 2 current carrying conductors, and the #10 cords would have an ampacity of 30A.
Yeah, I guess that all makes sense. Its seems odd they include a neutral wire, but I guess they want to use a 4-pole plug of whatever sort, and it's not kosher to have the neutral pin not connected to anything. Moot I suppose, since it seems cheaper to buy a pre-made extension cord than to make my own. My hardwired EVSE (at main home) has no neutral.
 
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