120V to 240V Transformer

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cpthk

New member
Joined
Feb 19, 2018
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2
I saw amazon sell the 120V to 240V transformer. Some brands only cost < $100. (like this) Even the more expensive ones are still under < $200. (like this) Could I use this to convert my house 120V to 240V for the leaf to get level 2 charging? Is there any down side to this? I prefer this since I don't need to hire a electrician to wire a 240V outlet, and no drilling to the house. It is also portable that I could move this anywhere I like. It is also cheaper. Thanks.
 
Most 120v outlet can provide a maximum of 12 amp (1,440watts) no matter what you do after the outlet you won't be able to draw more power or you will trip the braker or burn the wire, some outlets let you draw 16 amp (1,920 watts) usually those in the kitchen area, no matter if you increase the voltage after you have a limit per outlet, you will need to get 220v from the panel to a new 220v outlet, there are other options but are against electric codes.
 
I thought the leaf (with an appropriate evse) could already draw up to the max amperage on 110vac?

Why would you need the losses of the step up transformer when the leaf can already draw up to 24 amps of 110vac?
 
cpthk said:
I saw amazon sell the 120V to 240V transformer. Some brands only cost < $100. (like this) Even the more expensive ones are still under < $200. (like this) Could I use this to convert my house 120V to 240V for the leaf to get level 2 charging? Is there any down side to this? I prefer this since I don't need to hire a electrician to wire a 240V outlet, and no drilling to the house. It is also portable that I could move this anywhere I like. It is also cheaper. Thanks.

If your converter doubles the voltage it will also be halving the amperage. The total energy (Watts) available does not increase, in fact it goes down because of conversion losses in the transformer. When I was a kid I thought I could power the whole house from a 9V battery if I could make the right kind of transformer. Alas, it doesn't work that way. :(
 
Some of us, with wonderful instructions created by (IIRC) user Ingineer, built an adapter that allows you to plug into two 120v outlets on different circuits to obtain 240v for opportunity charging. I'll try to find the thread. Edit: Here you go:

http://www.mynissanleaf.com/viewtopic.php?t=4330
 
You will be far better off doing it right.
Cut sheet rock, drill holes, pull wire, be happy.
It's just part of EV ownership.

Unless you were already wired up for big welders, plasma cutter, large air compressors and therefore already had easy access to multiple big 240v plugs in your driveway/ garage area.
 
Thanks, everyone.

Is there a thing to plug from two 120V outlet and adds up the wattage? Of course I would connect from two outlets from different rooms that do not share the same circuit breaker.
 
It is possible, but they don't just need to be on different breakers, the breakers need to be on different legs of the split-phase AC service. Then you still have the problem that most branch circuits are 15 A and the cheap 240 V EVSEs try to feed your car 16A, which will likely trip breakers or possibly overheat wiring if the breakers fail to trip when they should.

Like others have said, you really need to find a way to get a 240 V circuit run to somewhere close to where you park your car. 40 or 50 A would be ideal for maximum charging rate, but 20 A will do if you are looking for the cheapest level 2 EVSE possible and you are OK with 40% slower charging (but still about 3x faster than level 1).
 
Just a note most every leaf will charge at least 16amps even on 110vac with a proper EVSE AND outlet.

20amp 120vac circuits are quite common and even the classic 30/50 amp. 110vac RV plugs aren’t unheard of

If he doesn’t care about the 1900 watt charge rate it is possible he could get a 20 amp 110vac outlet and evse.

It’s still better than 12 amps
 
rmay635703 said:
Just a note most every leaf will charge at least 16amps even on 110vac with a proper EVSE AND outlet.

20amp 120vac circuits are quite common and even the classic 30/50 amp. 110vac RV plugs aren’t unheard of

If he doesn’t care about the 1900 watt charge rate it is possible he could get a 20 amp 110vac outlet and evse.

It’s still better than 12 amps

If he can run a 20 amp cable then he can connect it as a 240 volt 20A circuit, with a hardwired 16A L-2 EVSE. He just needs to connect (and label!) the unnecessary neutral wire as a second Hot wire.
 
LeftieBiker said:
rmay635703 said:
Just a note most every leaf will charge at least 16amps even on 110vac with a proper EVSE AND outlet.

20amp 120vac circuits are quite common and even the classic 30/50 amp. 110vac RV plugs aren’t unheard of

If he doesn’t care about the 1900 watt charge rate it is possible he could get a 20 amp 110vac outlet and evse.

It’s still better than 12 amps

If he can run a 20 amp cable then he can connect it as a 240 volt 20A circuit, with a hardwired 16A L-2 EVSE. He just needs to connect (and label!) the unnecessary neutral wire as a second Hot wire.

True but why would he need to run cable?

Every house I’ve ever been in had a 20 amp or 30 amp breaker with 12 or 10 gage wires running to a string of outlets, if his breaker is already one of those ratings he can easily have one outlet swapped out for a 20 or 30 amp style matching his breaker rating
 
cpthk said:
Thanks, everyone.

Is there a thing to plug from two 120V outlet and adds up the wattage? Of course I would connect from two outlets from different rooms that do not share the same circuit breaker.

Yep. It’s called a “Quick 220”. Combines two 120 volt opposite leg circuits to make 240 volt. There is a 15 amp and a 20 amp model. Neither circuit can be a GFCI. It does it in a safe manner so if one side fails it kicks off both. Most people get the 15 amp model because that’s what the breakers are.

Then you need an LCS-15 clipper creek EVSE. You will have a 12 amp 240 volt EVSE that will charge your EV more than twice as fast as standard 120.

There is at least one and maybe two townhouses in our community doing this. Although we don’t use the Quick 220 device we do have an LCS-15 EVSE. Works well.

Having said all that, getting a 20 or even 50 amp line pulled might not be that much more than one of these devices...if at all.
 
Just because the receptacles are in different rooms doesn't automatically mean they are on different breakers.

I do most of my charging with the original 12 amp Panasonic made granny evse that I converted to 240v.
 
rmay635703 said:
True but why would he need to run cable?

Every house I’ve ever been in had a 20 amp or 30 amp breaker with 12 or 10 gage wires running to a string of outlets, if his breaker is already one of those ratings he can easily have one outlet swapped out for a 20 or 30 amp style matching his breaker rating

They have? Most houses I've seen have 14 gauge wire with 15a breakers. They will often have a bigger circuit or two going to the kitchen, but that one is almost always loaded with kitchen appliances and not available for EV charging.
 
davewill said:
rmay635703 said:
True but why would he need to run cable?

Every house I’ve ever been in had a 20 amp or 30 amp breaker with 12 or 10 gage wires running to a string of outlets, if his breaker is already one of those ratings he can easily have one outlet swapped out for a 20 or 30 amp style matching his breaker rating

They have? Most houses I've seen have 14 gauge wire with 15a breakers. They will often have a bigger circuit or two going to the kitchen, but that one is almost always loaded with kitchen appliances and not available for EV charging.

I agree. There is often at least one "appliance" circuit that is 20A, but you can't convert a multi-outlet circuit to 240 volts, and you can't use that awful "Quick 220" with just one leg. I was talking about options IF new cable had to be run, BTW, not saying that cable must be run.
 
Oilpan4 said:
You will be far better off doing it right.
Cut sheet rock, drill holes, pull wire, be happy.
It's just part of EV ownership.

Unless you were already wired up for big welders, plasma cutter, large air compressors and therefore already had easy access to multiple big 240v plugs in your driveway/ garage area.
I agree, but I can relate to the OP comment. In my case, I bought a LEAF but have restrictions to rewiring the house. Every electrician said I need a service upgrade. The lowest estimate I received was $4,000 to upgrade the panel and run a 40-amp circuit. That is bad enough, but I am in the middle of a divorce where it is unclear whether or not I will keep the house, so there is no point in spending the money right now. Even if I wanted to spend the money, I cannot spend money outside of normal, everyday expenses while the divorce is underway. To make it even more interesting, I have no room in the garage, so I need a level-2 cable that will fit under the garage door.

My solution was to buy a 40 amp breaker, 35 feet of 8/3 uf wire, and a 14-50 receptacle from the local hardware store. I was able to connect the wire to the breaker inside the box and run it along the inside wall of the garage to a 14-50 receptacle attached to the included EVSE that is coiled up on a rolling stool. When I need to charge, I roll the stool out of the garage and the flat cable fits neatly under the closed garage door.

The whole project cost $130 and a Saturday afternoon.
 
davewill said:
rmay635703 said:
True but why would he need to run cable?

Every house I’ve ever been in had a 20 amp or 30 amp breaker with 12 or 10 gage wires running to a string of outlets, if his breaker is already one of those ratings he can easily have one outlet swapped out for a 20 or 30 amp style matching his breaker rating

They have? Most houses I've seen have 14 gauge wire with 15a breakers. They will often have a bigger circuit or two going to the kitchen, but that one is almost always loaded with kitchen appliances and not available for EV charging.

This must be regional, I should photo my current box , not a single 15 amp breaker in my panel, I’m going down to see the panel in this home now
 
My relatives house has
9 20 amp breakers
3 15 amp breakers labeled “lighting”
1 double throw 40amp
1 double throw 30 amp
1 double throw 20 amp

Not a single 15 amp that goes to an outlet to be seen.

And I can’t attach a photo since this forum is stuck in 1994, this is the only forum I have belonged to that doesn’t allow attachments (excluding bravenet in 1998)
 
cpthk said:
Thanks, everyone.

Is there a thing to plug from two 120V outlet and adds up the wattage? Of course I would connect from two outlets from different rooms that do not share the same circuit breaker.
I built my own but here's one already made and has features mine doesn't. Note as someone else said, the 2 120v outlets need to be on a different phase of your panel. A panel that has the ability for 240v(almost all except very old ones) will have both a A and B side, to use something like the Quick220v device you need to find a outlet on the A and then B side, otherwise it won't work, you'll just get 0v between the 2 outlets.
https://www.quick220.com/
 
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