Safe to charge via dryer outlet?

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mikelb

Member
Joined
Jul 28, 2014
Messages
8
Location
Pasadena, CA
I have a dryer outlet that is 30A, 250V. Is it safe to charge by unplugging the dryer and plugging in the EV when I need to charge, and plugging in the dryer when it's needed? Are there any safety concerns?

Thanks!
 
A lot of plug/unplug cycles are bad for both the outlet and the plugs. This isn't a great solution long-term so you need to either run a new circuit, or come up with an either/or switch that can toggle two dryer outlets so that only one can be on at a time. For now it's ok as long as the plugs fit tightly.
 
mikelb said:
I have a dryer outlet that is 30A, 250V. Is it safe to charge by unplugging the dryer and plugging in the EV when I need to charge, and plugging in the dryer when it's needed? Are there any safety concerns?

Thanks!
DO NOT, UNDER ANY CIRCUMSTANCES, plug an unmodified 120v evse, such as the one that came with your Leaf, into a 240v outlet.

As was already stated, you can get an EVSE rated 24 amps or less, or update the circuit to 40 amps and use a 30 amp EVSE. This would be my choice, as long as the wires will handle 40 amps. Just replace the circuit breaker, then install an additional outlet next to the current one, using the type of outlet that the EVSE uses. Leave both the dryer and the EVSE plugged in all the time, but NEVER use the dryer when the EV is charging.
 
Graffi said:
As was already stated, you can get an EVSE rated 24 amps or less, or update the circuit to 40 amps and use a 30 amp EVSE. This would be my choice, as long as the wires will handle 40 amps. Just replace the circuit breaker, then install an additional outlet next to the current one, using the type of outlet that the EVSE uses. Leave both the dryer and the EVSE plugged in all the time, but NEVER use the dryer when the EV is charging.

That's absolutely against code. Only one 240V device allowed per circuit. "Remembering" to never run them together is subject to error either by forgetfulness or perhaps visitors "helping out". And "the circuit breaker will save me" is not the right way to look at it.

As far as plugging into the dryer socket; it will work but the average dryer socket is not designed for a high number of plug/unplug cycles. A worn or loose plug-socket connection is bad news when you're pulling a constant 20 amps. This is a high-power, long-duration application. Everything about the circuit and connections should be top-notch.
 
Similar question. I have a Bosch 240V 16 amp EVSE and an unused 3 prong 240V 30 amp dryer outlet (considered the old style outlet). The EVSE requires a hard wired connection. I purchased a dryer cord, installed it to the EVSE and found that it works!

However, the Bosch requires 2 hot leads and a ground, whereas the 3 prong outlet has 2 hot leads and a neutral.

Is this safe? If not, how is evseupgrade getting around this with their adapter?

Thx.
Mark
 
Yes, the old plug used a shared Neutral/Ground.
The only difference is the color of the insulation. Connects same electrically in the main panel.
 
Phatcat73 said:
Similar question. I have a Bosch 240V 16 amp EVSE and an unused 3 prong 240V 30 amp dryer outlet (considered the old style outlet). The EVSE requires a hard wired connection. I purchased a dryer cord, installed it to the EVSE and found that it works!

However, the Bosch requires 2 hot leads and a ground, whereas the 3 prong outlet has 2 hot leads and a neutral.

Is this safe? If not, how is evseupgrade getting around this with their adapter?

Thx.
Mark
Read through the information provided re: neutral vs. ground is this previous thread:
http://www.mynissanleaf.com/viewtopic.php?f=26&t=17637&p=383180#p383180
 
Graffi said:
Leave both the dryer and the EVSE plugged in all the time, but NEVER use the dryer when the EV is charging.

That is neither code, nor safe.

You are literally betting a possible fire that the circuit breaker will save the day.
 
LeftieBiker said:
Yes, that's why I suggested an either/or switch.
30 Amp manual xfer switch (generator panel) feeding 2 permanent 30A outlets 14-30R & 6-30R, but money would be better spent on a chunk of 8/3 loomex or teck cable c/w 40A breaker for the EVSE. The breaker will run cooler and from what I've seen in the field most L2 EVSE's manufacturer specs require this. Canadian electric code would would require 2 dedicated circuits. I can't see it any different in the States.
 
TonyWilliams said:
Graffi said:
Leave both the dryer and the EVSE plugged in all the time, but NEVER use the dryer when the EV is charging.

That is neither code, nor safe.

You are literally betting a possible fire that the circuit breaker will save the day.

Same could be said about having multiple receptacles on a 120 volt circuit. Circuit breakers save the day thousands and thousands of times a day.

NEC allows multiple 240 volt receptacles on one circuit so I'm wondering what would preclude someone from doing this (besides the obvious thing that it is a bit silly and not nearly as safe as a dedicated circuit.)
 
Besides literally "playing with fire", I don't understand why someone would risk a $30k+ automobile on poor/risky EVSE implementations. For the record, I have used an EVSEUpgrade unit on a dedicated dryer socket in my garage since I bought my Leaf with no issues (I rarely plug/un-plug the unit).
 
QueenBee said:
Same could be said about having multiple receptacles on a 120 volt circuit. Circuit breakers save the day thousands and thousands of times a day.

Two heavy-draw devices on a 240V circuit is essentially a planned, deliberate and extreme overload at high power levels. Breakers save the day, yes that's their job. But still, don't take foolish chances. Breakers can and do fail. 240V devices by their nature are both high-voltage and high-amperage. While overloads of any type are to be avoided, they're generally more severe in the case of 240V circuits. And there's a difference between an incidental overload, and designing an overload.
 
Nubo said:
QueenBee said:
Same could be said about having multiple receptacles on a 120 volt circuit. Circuit breakers save the day thousands and thousands of times a day.

Two heavy-draw devices on a 240V circuit is essentially a planned, deliberate and extreme overload at high power levels. Breakers save the day, yes that's their job. But still, don't take foolish chances. Breakers can and do fail. 240V devices by their nature are both high-voltage and high-amperage. While overloads of any type are to be avoided, they're generally more severe in the case of 240V circuits. And there's a difference between an incidental overload, and designing an overload.

Anyway my point was just regardless of your opinion the NEC does allow multiple receptacles on a 240 volt circuit.

There are lots of situations were 240 volt with high amperage is designed that you aren't going to turn everything on at once and if you do that a circuit breaker/fuse is going to protect the wires. For example maxing out every circuit in your house will overload your service. If you and your neighbors all use too much power you'll overload the likely 25kva transformers that are often shared among many homes.

But like I said it's a bit silly and not nearly as safe as a dedicated circuit.
 
Technically, the 3-prong dryer socket is ungrounded, wired as 2 hot lines and the Neutral, right?

Then, the dryer is allowed to use the 10-30 Neutral slightly incorrectly as the chassis Ground, right?
 
garygid said:
Technically, the 3-prong dryer socket is ungrounded, wired as 2 hot lines and the Neutral, right?

Then, the dryer is allowed to use the 10-30 Neutral slightly incorrectly as the chassis Ground, right?

I guess that would be sora true since you'd connect this to the nuetral bus bar if they were seperated in the panel but I guess you could also say that it's technically the EGC and nuetral wire.
 
I've found this thread incredibly helpful. In my case I plan to extend my existing #10 wire another 10 feet from my dryer circuit through the wall into the garage. I'm having an electrician buddy do the work but I've already purchased an industrial grade 30 amp double pole double pole switch as suggested in this thread. It looks like a standard switch so the spouse can use it without intimidation. Heavier wire though would require a larger type of switch. Hopefully, like me, others can use this to kickstart their electrician into keeping to code, and keeping the install bills at a minimum. Then with my EVSE Upgrade I have the easiest possible plan for level 2 charging.
 
CGKyle said:
Heavier wire though would require a larger type of switch.

If the switch is not rated to accept a larger gauge wire one thing electricians will do is add a pig tail with the the largest gauge it does accept and then use the proper size wire nut.
 
You are not allowed to use the dryer outlet for an EVSE. This is new to the 2014 NEC. See Art 210.17:

"An outlet(s) installed for the purpose of charging electric vehicles shall be supplied by a separate branch circuit. This circuit shall have no other outlets."

Check to see what Code cycle your town uses.
 
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