Extension of dryer outlet for EV charging

My house has a 150A panel and is too full to accommodate a 30-50A dedicated circuit for an EV charger in my garage.
I'm not sure it's worth the investment in a new panel and routing an EV charger plug, so I'm looking for a legal/code-OK cheaper solution.

I have a 30A circuit for my dryer.

1) My EV is a Nissan Leaf Soul S, so its max charging current draw is 27A. I read that plenty of people use that charger in their dryer outlet, because 27A<30A. While 27A<30A, I understand should apply a 1.25 factor for continuous charging, so 27x1.25 would be 32A.
- is it still OK to charger from the 30A (and if not will the breaker just trip, rather that the house catching fire?)
- I could buy a charger that can be dialed down to a max of 24A, so it would be OK for the 30A circuit, at the expense of slightly slower charging
- I could check the wire gauge between the panel and the outlet, but it's likely sized for 30A, but I could pull new bigger wire and upgrade the breaker to 40A or 50A (with wire to match). The distance between the panel and the outlet is not huge, so both cost and effort should be OK. I'm not sure it if's OK to swap a 30A breaker with a 40A in a 150A panel (keep reading, not talking about operating the dryer and charger at the same time)

2) Now the 240V outlets are not designed for plugging and unplugging all the time (unless I replace it with an industrial outlet) and honestly it's not practical to always unplug the dryer to plug in the EVSE, so I would use a swapping device (something like https://getneocharge.com/products/nema-14-30) that would only current to the ESVE when the dryer is not in use.

3) The dryer outlet is not in the garage, but in the laundry room which shares a wall with the garage. I'm trying to find the right instructions on how to route an extension between the laundry room and the garage (you can't just poke a hole in the wall and pass an extension cord through it). I think the following would work:

outlet in the garage mounted in a metal box -> metal conduit along the garage wall *through* the wall to the laundry room -> metal conduit along the landry room -> metal junction box -> short(3ft?) male dryer plug that will then plug into the load splitter
Use THNN wire of the right gauge in the conduit.


That's a little bit convoluted, so I'd have to weigh that against the cost of a panel upgrade and routing a dedicate 30-40-50A to the garage (the Leaf will only draw 27A when charging, but if I invest in the works, I will likely size it for a 50a circuit in case I get a different EV later)

I feel comfortable with doing the work described above myself, I haven't looked at what it would take to replace the panel on my own, but probably something I wouldn't do (I've installed a 30A subpanel in the basement off the main panel but I've never dealt with the main supply to the house)

Hi IAmAllThumbs,
Congratulations on your new car. I hope you enjoy it for many years!

One Big Glitch in Your Plans-
Unless the code has changed since my last update class, and assuming that your area is covered by NFPA 70; Article 210.17 requires that the EV charger be a dedicated circuit. No other receptacle outlets (or other loads) can be on that circuit. Part of the reasoning for the rule is that this is done to ensure that the circuit won't be overloaded. Circuit breakers do sometimes fail to open. (In your case, operating the clothes dryer while the car is charging.)

Work Around To The Full Load Center Problem-
Can you install Tandem (sometimes called "Piggy Back") circuit breakers to make spaces available for a new dedicated 40 amp circuit for your charger? This is commonly done and is less expensive than installing a sub panel.

Some load centers won't allow the use of tandem circuit breakers and some will. Some allow them in certain spaces.
From the NFPA 70: “A panelboard shall be provided with physical means to prevent the installation of more overcurrent devices than that number for which the panelboard was designed, rated, and listed.”

As an example, the main load center in my house has 24 spaces, but is designed, rated and listed for 42 overcurrent devices. Therefore I can use tandem in any space. A sub panel I have has 12 spaces and is designed, rated and listed for 12 overcurrent devices. i can not use tandem (without cheating and removing the rejection tab which I do not recommend). The garage panel has 8 spaces and tandems are allowed in 2 of the spaces.

You will have to research the model of your load center to find out if tandems are allowed.


How To Tandem-
Choose 4 single-pole circuit breakers. Replace them with two tandem circuit breakers. In the now empty two spaces, install your 40 amp circuit breaker for the EV charge. If the circuit breakers are not the same amperage, you can get mixed 15/20's (One half will be 15 and one half will be 20 amp) Each half of the tandem will provide full load current to its load. The bus bar is rated 150 amps, so there is no problem there. (You cannot do this with AFCI or GFCI circuit breakers as there are no tandems for those.)

One Word Of Advice-
I very much advise that you do this work under a permit& with inspection(s). Many jurisdictions allow homeowners to obtain very inexpensive permits for electrical work.

The primary reason is that should there ever be a fire or injury, if the job was not done under a permit and with inspection approval, the insurance company is under no obligation to pay any claims. Unfortunately, even if the fire or injury had nothing to do with your new work, the insurance company still has an escape. (I have often been used as an impartial witness in tort and arbitration cases. I have seen many examples of a claim being dismissed for a fire or injury because totally un-premitted work was discovered, thus rendering the insurance policy void.)

The second reason is to have a second person look at your work (the inspector). Something you missed or could have done better may be seen and advice for correction will be given.

I hope this post is helpful. Be sure to let us know how you proceed and how you like the new car!
Paul

Thanks for the answer. The splitter device i reference will.only allow one device (dryer or EV).to operate at once. One side (the dryer) gets priority.

I have have several 15 amp tandem breakers (2 circuits in one breaker slot). I will take a better look at my panel and see if:
a) I could create more room for another 30A
b) I'll read up on how you decide your panel has reached capacity

And I would absolutely get a permit and inspection for all the reasons you mention. When I installed a sub-oanel.jn the basement years ago, the inspector complimented my wiring.

Yikes! It's worse than I remember. Doesn't look like much room here.
I also need to trace and label the existing circuits because most of them are so faded you can't read and maybe they're not longer valid.

IamAllThumbs said:

Thanks for the answer. The splitter device i reference will.only allow one device (dryer or EV).to operate at once. One side (the dryer) gets priority.

Click to expand...

I suppose it would work, but NFPA 70 210.17 requires a dedicated circuit for EV chargers. I'm not sure how that would mix with 210.17's rules.
You are not installing or modifying any building wiring, so my opinion would be that 210.17 does not apply.
Running a cord through a wall to get in the garage is not allowed. Don't know how you can get in the garage with a cord.
Maybe a cord made with flat festoon cable or FCC run under the door when needed and pulled back when done charging?

IamAllThumbs said:

Yikes! It's worse than I remember. Doesn't look like much room here.

Click to expand...

Some years ago, your solution would have been easy: Move the air conditioner circuit to a fused disconnect fed from the meter. But now 230.72(A), if I remember the article number correctly, causes a glitch unless your main disconnect is also next to the meter & you install dual conductor lugs in the meter.

BUT...
There may be a nearly free work-around. If your electric utility has special rates for air conditioning, such as time-of-day or interruptible, they* can put a meter outside for the air conditioner. You will move your air conditioner circuit from your existing load center to the new outdoor service. Now you have 2 spaces indoors for a 40 amp EV charger.

* Electric utilities are not covered by NFPA 70, so they get to do helpful stuff that we can't. I was a high-voltage wireman years ago. We were covered by The Green Book and got away with all kinds of stuff that would make code writers have heart attacks.


Plan B:
A Main Lug sub panel would not be difficult for you to install if there is space next to the panel. You can even select it to allow future circuits for things. Size for what you guess you may want later. However, I'd opt for a load center swap instead. (Discussed below)

IamAllThumbs said:

Doesn't look like much room here.

Click to expand...

Have you considered swapping for a 150 amp load center with more spaces? It should be easy if you have room for the larger panel. You can de-energize to work safely, usually by pulling the meter. Some utilities will come out and disconnect for homeowners for free.

Several manufacturers make 20 and 42 space panels. Some make 30 space, 60 circuit panels.
You have a Homeline panel. I don't work residential or single phase, so I do not know if Square D offers a Homeline that will have spaces and let you re-use your existing breakers. I'll bet that they do.

One Caution-
The 2020 code has a new requirement for an outdoor disconnect for dwelling services. For a simple load center swap, the AHJ most likely is not able enforce this. ( And they usually don't.)But be sure to ask.
(If you increase your service from 150 amps to 200, more than likely an outdoor disconnect will be required.)

IamAllThumbs said:

When I installed a sub-oanel.jn the basement years ago, the inspector complimented my wiring.

Click to expand...

See above quote: You can do this job and even get complimented! You must do very good work.
Is there space & capacity in that sub panel for the EV or to move some 15's there to make room for the EV in the main load center

IamAllThumbs said:

b) I'll read up on how you decide your panel has reached capacity

Click to expand...

There are a bunch of on-line Residential Electric Load calculators based on NFPA 70's Part V, 220.82 and 83. I don't know how accurate they are, but they look easy.
So many people say "I added up my breaker amps and it is over my main breaker. I need a larger service" It doesn't work like that.

Another Plan-
Do you have natural gas available? Perhaps swap clothes dryers for a gas one to free up that circuit. Granted, that is crazy-expensive. But if you're in the market for a new clothes dryer perhaps this is a good time to switch to gas.

Thanks so much the very thorough answer. I think it'd switch to a gas stove before a gas dryer, but I think I'd rather stay with level 1 charging rather than spend the money). 'm having an electrician come get me a quote for free, to see what a pro would recommend, although I suspect their interest and mine are not full aligned.

I love the idea of having the power company split off the AC for me, but I think that in my area they replace you thermostat with a wifi enabled one. so they can override the command from your thermostat to your AC, rather than split off on their own controlled power box. Not sure though.

I tried to use the residential load calculator, there is a lot of guesswork, but with a 12kW EV charger (as big as they get for home) the total load form the calculator is about 109A (gas water heater and furnace help), so I think I have headroom in the service for an EV charger.

I think I could replace the top 50A breaker (I think that's the stove) with a tandem/combo 15/50/15 and replace two of the dual 15s with another 15/50/15 and shuffle the 15A circuits as indicated by the color coding, but I have to refresh my memory about left vs right sides of the panel vs ground and neutral. that would get me 9.6KW/40A for the EV charger since the breaker is only 50A. My current EV has a max charging current of 27A so even a 40A circuit would be enough, but if I run the wires I will likely size them for 60A in case we eventually figure out how to connect that much to the panel (I couldn't find a 15/60/15, that's starting to be a lot of amps in a small breaker so they probably don't exit)

I see they also make 30/40 combo quad breakers like https://www.homedepot.com/pep/Sieme...uble-Pole-Circuit-Breaker-Q24030CT2/302907611 which I could put in the 30amp slot and do less wiring

That would limit the RV charging to 32 amps (allowing for the derating on a 40 amps breaker), that's more than my LEAF can take, but falls short of 48A which is the max residential (on a 60A breaker)

I haven't looked very hard but I haven't found a quad 30/50. Edit, NVM here is one: https://www.homedepot.com/pep/Squar...Tandem-Circuit-Breaker-HOMT230250CP/311939386

I saw a video on how to calculate if your service can take a breaker of a certain size by downloading your usage data from your power company. Xcel doesn't make it easy but I can get it in 15 minutes increment. It allows you to see what the maximum instantaneous draw was in the last year.

According to the video, Max Amp last year x 1.25 + new breaker rating must be below the max breaker (150A here).

The Pro just came in to provide an estimate. His solution is the same as mine: quad 40/30 breaker to replace the 30A. Conduit from the load center on the outside of the wall.
I would have done a junction box inside the garage, they propose to do a junction box on the outside and penetrate with Romex to the back of the charger to eliminate a junction box sticking out in the garage. I didn't realize you could connect your own Romex to the charger rather that using their provide "whip" connector.

Quoted me $2K for the job, with a free upgrade to gauge 6 wire in case I want to replace the breaker with a 50A later. Not sure why not wire a 50A now, the charging current limit is set by the charger, not the breaker, so limit it to 32A for my current car, with an option to go to 40A in my next car.

That seems pretty steep for running 20 feet of conduit on the outside of the house (there is a door in the way, so I guess you need a little extra to go around it.

I'll probably bring another pro for a second quote or see if they have another suggestion. I was thinking about being lazy and having someone do it instead of DIY, but not for $2k.

PJB12 said:

Hi IAmAllThumbs,
Congratulations on your new car. I hope you enjoy it for many years!

One Big Glitch in Your Plans-
Unless the code has changed since my last update class, and assuming that your area is covered by NFPA 70; Article 210.17 requires that the EV charger be a dedicated circuit. No other receptacle outlets (or other loads) can be on that circuit. Part of the reasoning for the rule is that this is done to ensure that the circuit won't be overloaded. Circuit breakers do sometimes fail to open. (In your case, operating the clothes dryer while the car is charging.)

Work Around To The Full Load Center Problem-
Can you install Tandem (sometimes called "Piggy Back") circuit breakers to make spaces available for a new dedicated 40 amp circuit for your charger? This is commonly done and is less expensive than installing a sub panel.

Some load centers won't allow the use of tandem circuit breakers and some will. Some allow them in certain spaces.
From the NFPA 70: “A panelboard shall be provided with physical means to prevent the installation of more overcurrent devices than that number for which the panelboard was designed, rated, and listed.”

As an example, the main load center in my house has 24 spaces, but is designed, rated and listed for 42 overcurrent devices. Therefore I can use tandem in any space. A sub panel I have has 12 spaces and is designed, rated and listed for 12 overcurrent devices. i can not use tandem (without cheating and removing the rejection tab which I do not recommend). The garage panel has 8 spaces and tandems are allowed in 2 of the spaces.

You will have to research the model of your load center to find out if tandems are allowed.


How To Tandem-
Choose 4 single-pole circuit breakers. Replace them with two tandem circuit breakers. In the now empty two spaces, install your 40 amp circuit breaker for the EV charge. If the circuit breakers are not the same amperage, you can get mixed 15/20's (One half will be 15 and one half will be 20 amp) Each half of the tandem will provide full load current to its load. The bus bar is rated 150 amps, so there is no problem there. (You cannot do this with AFCI or GFCI circuit breakers as there are no tandems for those.)

One Word Of Advice-
I very much advise that you do this work under a permit& with inspection(s). Many jurisdictions allow homeowners to obtain very inexpensive permits for electrical work.

The primary reason is that should there ever be a fire or injury, if the job was not done under a permit and with inspection approval, the insurance company is under no obligation to pay any claims. Unfortunately, even if the fire or injury had nothing to do with your new work, the insurance company still has an escape. (I have often been used as an impartial witness in tort and arbitration cases. I have seen many examples of a claim being dismissed for a fire or injury because totally un-premitted work was discovered, thus rendering the insurance policy void.)

The second reason is to have a second person look at your work (the inspector). Something you missed or could have done better may be seen and advice for correction will be given.

I hope this post is helpful. Be sure to let us know how you proceed and how you like the new car!
Paul

Click to expand...

I have wrestled with the issue of an oversubscribed main panel since moving into a 2005 home in southern California. 1) I put in a subpanel (220 V table saw and two EVs which needed up to 40 amps) in my garage with 2 ga cable on a 90 amp breaker pulled through 2" gray PVC conduit per code, under a permit, and passed inspectors' oversight. 2) I wanted to install a 30 amp point of use, tankless water heater under the kitchen sink to avoid wasting gallons of water (60 ft from house water heater) every time my wife wants hot water. Main panel was really full. I considered another subpanel but then discovered the quad breakers that you proposed in the annotated picture above. I think that is your best option. Another point I discovered as I was putting in my charger circuit from the garage subpanel is that EV charger outlets need to be industrial or EV rated to be code and not overheat due to continuously drawing current for hours while charging. A standard, residential dryer outlet from Homedepot runs the risk of overheating and melting or shorting. Lastly, I put the car charger on a GFCI breaker as code recommended, but the charger did not play well with the GFCI and repeatedly tripped the GF protection, so I replaced it with the same capacity standard breaker and have had no problems.

P.S. Look at some of your 15 amp lighting branch circuits. As I have gone through this house and the main panel, I found several 15 amp breakers that were serving a few LED lights and/or under cabinet LED lights. Those circuits could be combined because the LEDs pull so little current and free up spaces on the main panel. Many homes have replaced 60 or 100 watt incandescent lights with LEDs making this investigation worthwhile to free up space in a main panel.

Thanks.for the feedback. Despite the title of the thread, my thinking has changed from extending the dryer to doing a hardwired install. I've seen the pictures of the dryer outlets getting fried.

IamAllThumbs said:

The Pro just came in to provide an estimate. His solution is the same as mine: quad 40/30 breaker to replace the 30A. Conduit from the load center on the outside of the wall.
I would have done a junction box inside the garage, they propose to do a junction box on the outside and penetrate with Romex to the back of the charger to eliminate a junction box sticking out in the garage. I didn't realize you could connect your own Romex to the charger rather that using their provide "whip" connector.

Quoted me $2K for the job, with a free upgrade to gauge 6 wire in case I want to replace the breaker with a 50A later. Not sure why not wire a 50A now, the charging current limit is set by the charger, not the breaker, so limit it to 32A for my current car, with an option to go to 40A in my next car.

That seems pretty steep for running 20 feet of conduit on the outside of the house (there is a door in the way, so I guess you need a little extra to go around it.

I'll probably bring another pro for a second quote or see if they have another suggestion. I was thinking about being lazy and having someone do it instead of DIY, but not for $2k.

Click to expand...

The 2,000.00 seems kind of high for the job as you described. Your thoughts about having a second (and maybe third) opinion are wise. Remember to insist on permits.

Check with your utility and maybe the IRS (if you are in United States). There might be some tax rebate or incentive for wiring upgrades to install an electric vehicle charging station. Does the manufacturer help out?

IamAllThumbs said:

Conduit from the load center on the outside of the wall.
I would have done a junction box inside the garage, they propose to do a junction box on the outside and penetrate with Romex to the back of the charger to eliminate a junction box sticking out in the garage. I didn't realize you could connect your own Romex to the charger rather that using their provide "whip" connector

Click to expand...

I don't work residential, but I'm not sure you can do what is proposed. I'm pretty sure that if you permanently hard-wire the charger you will need a local disconnecting means. (If you hard-wire a receptacle for the plug-in charger, you don't.)

Me? I think I'd pipe inside (for appearances) and install a dedicated receptacle outlet on the outside wall- with proper weather protection. I'd most likely pipe to a Jake or an LB to turn 90 and use a short length to go through the wall into the back of the receptacle box. Pipe all the way.

But that is just me. There are many ways to do the job.
Paul

PS:
One benefit to not hard-wiring the charger is theft when you're not home. Those things get stolen non stop around here. If you use cord-and-plug, you can take in the charger when done.
Many people here put the charger in the garage and drag out a cord for charging, rolling it back into the garage when done.

Thanks for the insight. I will absolutely insist on a permit.
I want the charger in the garage, where we park the car, not on the outside (although I had never considered theft).
I've read so many horror stories about poor receptacles that I'm OK with hardwired

According to NEC 2023 (in effect where I live) requires a disconnect only over 60A or over 150V to ground. This project would be 50A max, and 240V split phase so only 120V to ground.

IamAllThumbs said:

Thanks for the insight. I will absolutely insist on a permit.
I want the charger in the garage, where we park the car, not on the outside (although I had never considered theft).
I've read so many horror stories about poor receptacles that I'm OK with hardwired

According to NEC 2023 (in effect where I live) requires a disconnect only over 60A or over 150V to ground. This project would be 50A max, and 240V split phase so only 120V to ground.

Click to expand...

Your plan sounds very good!

I apologize. I thought the device was going outside, thus 225.31 might require the disconnect, depending on local interpretation. Your electrician will know what the local inspectors want.

Here they require a disconnect within sight, even below 60a. (Did one recently for a friend as hard-wired. AHJ was adamant about it.)
With the device indoors, they require a lockable circuit breaker which is satisfied by having a $2.00 breaker lock at the load center.

Sorry for the goof!
Paul