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I hope I got the physics correct on this question...

To have a home level 2 charger, I believe I need a 240 volt outlet. I have one; IN THE GARAGE. Yay. Unfortunately, it is already in use by our tankless water heater. Am I correct from my google search that there are extensions like there are for regular electrical outlets? That way I could plug the water heater in to one on the power strip and the Bolt charger into another.

Thanks, going to decide by tomorrow if I will be getting a bolt. this would make a difference due to cost issues.
 

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No no no!!!!!! Those tankless water heaters are power hungry and need to be on a dedicated outlet. If that tankless water heater is plugged into an outlet, it is probably hooked up to a 60 amp breaker. Throw a car charger on there and the best result is you trip the breaker. Please consult an electrician!
 

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The Bolt can/will draw up to 32amps while recharging, how many watts is the hot water heater and what size breaker is that circuit on?

You need a 40 amp breaker & 8ga wire for the Bolt.
 

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If your breaker is in the garage, and there is room in the panel, it's probably fairly easy/cheap to add another 240v breaker and wire in an outlet. Based on your question, I would not recommend you try installing it yourself. I wired in a NEMA 14-50R circuit to code for about $60 in parts, but I only had to go about 12 ft total length from the panel and had easy access to the attic above the ceiling of the garage.

If your typical commute isn't too long, you could just charge off L1 120v until you get around to having a dedicated 240v circuit installed. From a financial perspective, I would buy a used vehicle and save money if finances are so tight that installing a 240v circuit is too expensive.
 

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I hope I got the physics correct on this question...

To have a home level 2 charger, I believe I need a 240 volt outlet. I have one; IN THE GARAGE. Yay. Unfortunately, it is already in use by our tankless water heater. Am I correct from my google search that there are extensions like there are for regular electrical outlets? That way I could plug the water heater in to one on the power strip and the Bolt charger into another.

Thanks, going to decide by tomorrow if I will be getting a bolt. this would make a difference due to cost issues.
Many "power strips" are rated for 250V - BUT not for anywhere near the power draw of either the water heater or EVSE (the "charger" is built into the car and will handle 110, 120, 208 or 240V - or anything in between for that matter). High power appliances like water heaters and EVSE's also use plugs that are much different than those found on power strips

The NEC (National Electrical Code) requires that appliances such as a water heater, EVSE, oven, etc be installed on a dedicated circuit (nothing else connected). Those circuits are designed to the specific load requirements of the device connected to them and cannot be "shared" with anything else.

If you cannot afford to have an outlet installed for your EVSE, and you cannot get by with L1 AC charging (120V), then you need to delay the purchase of the Bolt. L1 AC is suitable if you drive ~25 miles a day (can vary greatly depending on climate and if the 120V circuit is shared with other devices (fridge/freezer as an example).
 

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To charge the car on the same circuit as your hot water heater, you can use the Smart EVSE controller. It can measure current draw from a shared device and throttle the car to keep from popping a breaker. Can't say that I recommend it with your 60amp (or more) hugemongous water heater. http://www.stegen.com/nl/ev-produkten/66-smart-evse-controller.html

Another option is to get a seimens versacharge EVSE. It has a charge inhibit pin that can be used to stop the car from charging. With a little creativity, you can add a little sensor to the hot water heater and inhibit the car from charging while the hot water heater is running. If it were me, I'd use a small 220v relay connected to the heater contacts in teh water heater.

But again, keep in mind the wires to that water heater are hugemongous and you still have to safety splice into the wiring. This is NOT your average 10gauge wire nut solution. Dare I guess the wires to your water heater are AWG4?

One other option... my tankless water heater is gas, but needs a small electric line for the electronics. Is your hot water heater electric or gas?
 

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Simplest (and safest) solution is to have an electrician pull a dedicated circuit from your main breaker to the garage. Since there's a circuit there now for the water heater, it's probably already been done and the electrician can just follow the same route. I had my electrician install my circuit in the garage for about $300. It's a 40 amp circuit, but he used wire rated for 75 amps if I ever wanted to upgrade in the future.
 

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To charge the car on the same circuit as your hot water heater, you can use the Smart EVSE controller. It can measure current draw from a shared device and throttle the car to keep from popping a breaker. Can't say that I recommend it with your 60amp (or more) hugemongous water heater. http://www.stegen.com/nl/ev-produkten/66-smart-evse-controller.html

Another option is to get a seimens versacharge EVSE. It has a charge inhibit pin that can be used to stop the car from charging. With a little creativity, you can add a little sensor to the hot water heater and inhibit the car from charging while the hot water heater is running. If it were me, I'd use a small 220v relay connected to the heater contacts in teh water heater.

But again, keep in mind the wires to that water heater are hugemongous and you still have to safety splice into the wiring. This is NOT your average 10gauge wire nut solution. Dare I guess the wires to your water heater are AWG4?

One other option... my tankless water heater is gas, but needs a small electric line for the electronics. Is your hot water heater electric or gas?
The smart EVSE is a controller only, and setting it up also requires the following:
This is only the controller, in order to build a EVSE you will also need:

A contactor/relais which switches on/off the mains power to the EV. For three phase systems this should be a 4 pole contactor with a coil rated for 230Vac, and rated for the maximum current the EV will charge with.

EV (type 2) socket, with 12V activated lock. When you plug in the charging cable, the Smart EVSE will lock the cable in place. If somehow the power to the Smart EVSE module is lost, the charging cable will automatically be unlocked from the socket.

Enclosure with DIN rail, for mounting the controller and contactor.

FTDI serial cable for upgrading the firmware of the module (optional).

When using Smart mode, the Smart EVSE module needs to be connected to the Sensorbox, the connection between the Smart EVSE controller and Sensorbox is RS485 with power (12V) (4 wires in total). The Sensorbox is powered from the Smart EVSE controller.
In order to measure the current of other appliances, CT's (current transformers) are used, which clamp on the MAINS wires directly after they enter the building. Usually three are used, one for each phase. They connect to the Sensorbox. You can buy them here: http://www.stegen.com/en/ev-products/92-current-transformer.html

However, the real issue is the 3 phase 230V power it is designed to work on.

Even if it worked on our single phase 240V, it is much more complex, more expensive, and questionable (at best) in meeting US electrical codes than installing a dedicated 240V circuit.
 

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Even if it worked on our single phase 240V, it is much more complex, more expensive, and questionable (at best) in meeting US electrical codes than installing a dedicated 240V circuit.
You are correct about all the additional parts needed to make it work... an enclosure and a $20 220v contactor from ebay. But insofar as making it work with single phase 220 in the US, that's a nonissue. The unit itself is power from two legs of power (ie 220v) and all it does is turn on the contactor when the car is connected. Maybe I'm naive but I cant see why 3 phase is even in play here. The charger in the car has to cope with 3 phase, not the EVSE.... and the Bolt works great off 220v single phase.
 

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I hope I got the physics correct on this question...

To have a home level 2 charger, I believe I need a 240 volt outlet. I have one; IN THE GARAGE. Yay. Unfortunately, it is already in use by our tankless water heater. Am I correct from my google search that there are extensions like there are for regular electrical outlets? That way I could plug the water heater in to one on the power strip and the Bolt charger into another.

Thanks, going to decide by tomorrow if I will be getting a bolt. this would make a difference due to cost issues.
Shared Plug Option
Look up "Dryer Buddy" by BSA electronics. He makes a smart switch to switch between plugs. It works by giving power to your charger unless there is a demand from the dryer (or heater). Usually not a problem if you have prioritized charging to occur during low rate off peak times in middle of night. Also has options to show actual amount of power used.
 

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You are correct about all the additional parts needed to make it work... an enclosure and a $20 220v contactor from ebay. But insofar as making it work with single phase 220 in the US, that's a nonissue. The unit itself is power from two legs of power (ie 220v) and all it does is turn on the contactor when the car is connected. Maybe I'm naive but I cant see why 3 phase is even in play here. The charger in the car has to cope with 3 phase, not the EVSE.... and the Bolt works great off 220v single phase.
Plus a cable and J1772 plug (EU charging assumes a socket on both ends and the user supllies a M/M Mennekes Type 2).
Plus clamp-on current transformers on the water heater lines
Plus the Sensorbox that is the interface between the current transformers and the controller
The sensors need to be clamped on the main power before the breaker box, their wires run to the EV Controller/sensorbox, then calibrated to recognize the load from the water heater.

This is a DIY solution in search of a problem, and certainly not a project for someone like the OP that is looking to run a 240V EVSE off a power strip.
 

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Discussion Starter #13
Thank you!!

All great advice. This is a fantastic forum with active, helpful members.

My last hurdle is today: taking SWMBO to see the BOLT.:eek:
 
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