Do It Yourself: 240v from two 120v sources

[DaveEV]

Finished up my Easy240 tonight. Click the pics for higher res (but grainy thanks to iPhone) pics.

Picture of guts:


Another pic of guts:


Plugged in and ready to go:


Charging the LEAF:

 

[johnr]

Looks good! Apparently it went fairly easily.

 

[TonyWilliams]

John, do you have the hard to find construction cable adapter? The one with a center pin?

 

[Ingineer]

John, do you have the hard to find construction cable adapter? The one with a center pin?

Are you talking about CS6365?

-Phil

 

[TonyWilliams]

John, do you have the hard to find construction cable adapter? The one with a center pin?

Are you talking about CS6365?

-Phil

Ya, that one.

 

[tps]

John, do you have the hard to find construction cable adapter? The one with a center pin?

Are you talking about CS6365?

-Phil

Ya, that one.

U bought mine on ebay.. Seem to remember it was about $35,,,

 

[johnr]

John, do you have the hard to find construction cable adapter? The one with a center pin?

Yes, I can make an adapter with the CS6365 plug (thanks Phil for the reference!) Of course, I'd have to order the plug, so give it a few days. And these plugs are expensive. The total price would be $69 shipped. If interested send me a PM.

 

[TonyWilliams]

Ok, I'll take one. PM sent.

 

[mwalsh]

As an FYI...I just had a situation where I found what I thought should be 208v (3-phase power) on two 120v outlets at my office. Turns out that they were fed from different breaker panels on two different transformers in our building and the result was actually 270v - too much voltage for the Ingineer modded EVSE.

Luckily, I've got into the habit of checking voltage first, with a voltmeter I carry in the car. Once I found a second outlet on a different phase of the same panel/transformer I got what I was expecting. But had I just taken the red lamp on my home brew 240v box at face value I would have probably damaged my EVSE.

 

[Ingineer]

I'm not sure how you were seeing 270v, but actually the EVSE would likely survive it, not so sure about the Leaf's on-board charger though! I wouldn't attempt it. If they are fed from totally different transformers, something weird could happen depending on how they were wired. In fact, something weird is already happening if you were reading 270v! :shock:

-Phil

 

[jaanton]

277v is often used for industrial lighting. See NEMA 7 plugs/recepticles. This is a single phase of a 480v three phase system. Maybe you're tapping into a lighting power panel? Interestingly... I've heard that the Tesla Model S chargers are being built to take up to 277 v. I imagine being stranded on the road and tapping into a 277v lamppost.

I'm not sure how you were seeing 270v, but actually the EVSE would likely survive it, not so sure about the Leaf's on-board charger though! I wouldn't attempt it. If they are fed from totally different transformers, something weird could happen depending on how they were wired. In fact, something weird is already happening if you were reading 270v! :shock:

-Phil

 

[gbarry42]

I assume if you're smart enough to carry a voltmeter and check the voltage first, you are also smart enough to put a small load across and see if the voltage is "real". Voltmeters are high impedance, and leakage currents can be weird.

Come to think of it, that LED circuit might be enough of a load for the purpose. Maybe adding an overvoltage indicator would be a good idea. :idea:

 

[Ingineer]

I assume if you're smart enough to carry a voltmeter and check the voltage first, you are also smart enough to put a small load across and see if the voltage is "real". Voltmeters are high impedance, and leakage currents can be weird.

Come to think of it, that LED circuit might be enough of a load for the purpose. Maybe adding an overvoltage indicator would be a good idea. :idea:

Yes, this could be added, but so far, only Mike Walsh's recent report is the only one ever seen "in the wild". Also, his has yet to be confirmed properly in any event.

You can always add features to cover any eventuality, but personally this is one that's not needed.

-Phil

 

[waidy]

I assume if you're smart enough to carry a voltmeter and check the voltage first, you are also smart enough to put a small load across and see if the voltage is "real". Voltmeters are high impedance, and leakage currents can be weird.

Come to think of it, that LED circuit might be enough of a load for the purpose. Maybe adding an overvoltage indicator would be a good idea. :idea:

Yes, this could be added, but so far, only Mike Walsh's recent report is the only one ever seen "in the wild". Also, his has yet to be confirmed properly in any event.

You can always add features to cover any eventuality, but personally this is one that's not needed.

-Phil

I thought Turbo3 made one already. See p.12 posted Mon Jan 23, 2012 5:29 pm. or http://www.mynissanleaf.com/viewtopic.php?f=26&t=4330&start=110" onclick="window.open(this.href);return false;

 

[Volusiano]

This is such an old thread to revive. But ..., I came across this article today on GreenCarReports http://www.greencarreports.com/news/1077296_want-to-charge-your-electric-car-from-two-110-volt-sockets-think-again" onclick="window.open(this.href);return false; and I'm a little puzzle as to why they say it's unsafe?

The author seems to imply that the bridge-converter is inherently unsafe. I don't understand why she would say that if the box is built properly with the proper wiring gauge and relay size. If you buy a commercial model like the Quick220, I'm sure it's beefy enough to handle the current level at the rated current. Build-it-yourself boxes done on this thread with the proper wiring gauge and relay size should also be safe.

Homes with proper wiring gauges for 15 amps or 20 amps draw should also be safe to use.

Of course if you use it in older homes with unsafe wiring then anything can be unsafe, not just the converter box.

It looks like somebody is running out of things to write so they have to start making stuff up to write about.

Want To Charge Your Electric Car From Two, 110-Volt Sockets? Think Again

By Nikki Gordon-Bloomfield Nikki Gordon-Bloomfield
1,018 views Jun 27, 2012

In our modern world, electricity is literally everywhere, easily assessible from a 110-volt outlet.

That’s fine for running things like laptop computers and televisions, but when it comes to electric cars, charging at 110-volts takes forever.

One solution, as some electric car drivers have discovered, is to use a product that combines two, 110-volt outlets to provide 240-volts of electricity that can power a modified, portable level-2 charging unit.

But as a friend who recently sold a 240-volt air conditioning unit discovered, powering a 240-volt device from two 110-volt sockets is normally a really, really bad idea.

As the friend explained, the couple who purchased his air conditioner didn’t have a suitable 240-volt, high current outlet to plug the unit into. Instead, they purchased a 110-volt bridging converter, designed to combine two separate 110-volt supplies with different phasing to provide 240-volts.

They phoned him up a little while later, complaining the unit wasn’t working and that there was a burning smell coming from the converter unit. Essentially, they had tried to draw more power from the combined sockets than they were safely capable of.

In a home, most outlets are rated to provide between 10 and 15 amps at 110-volts, while specialists 240-volt outlets for driers and kitchen appliances may handle 30 amps or more.

Electric car charging stations with dedicated electrical wiring or dedicated sockets will have been fitted with suitable grade wire that can handle the high current that level 2 charging stations demand.

A bridging converter on the other hand, isn’t designed to supply the high currents that electric car charging stations require for long periods of time.

Not only that, but in older houses with smaller gauge wiring, pulling a constant 15 amps or more from multiple wall outlets could overheat the wires in the wall, causing more than just a funny smell.

Our advice?

Where possible, use a dedicated charging station and/or wall outlet dedicated to safely providing the right power to charge an electric car.

And if you’re away from home?

Always. Plug. Your. Electric. Car. Into. An. Outlet. You. Know. Is. Rated. To. Take. The. High. Current.

 

[davewill]

This is such an old thread to revive. But ..., I came across this article today on GreenCarReports http://www.greencarreports.com/news/1077296_want-to-charge-your-electric-car-from-two-110-volt-sockets-think-again" onclick="window.open(this.href);return false; and I'm a little puzzle as to why they say it's unsafe? ...

Can't really disagree with her. If you've got old wiring, or old receptacles, a constant 16a draw IS a bad idea.

 

[Volusiano]

This is such an old thread to revive. But ..., I came across this article today on GreenCarReports http://www.greencarreports.com/news/1077296_want-to-charge-your-electric-car-from-two-110-volt-sockets-think-again" onclick="window.open(this.href);return false; and I'm a little puzzle as to why they say it's unsafe? ...

Can't really disagree with her. If you've got old wiring, or old receptacles, a constant 16a draw IS a bad idea.

I don't disagree about the old house wiring, of course. But I disagree when she said "A bridging converter on the other hand, isn’t designed to supply the high currents that electric car charging stations require for long periods of time." That's just generalization that implies that all converters are unsafe.

 

[mwalsh]

I'm saying nothing. Ms. Gordon-Bloomfield and I see eye-to-eye little enough already.

 

[TEG]

When Ingineer/Phil does the EVSE mod, he can do it for 12A or 16A.
(There is an "extra charge" for 16A... pun intended)

If you are using a "QUICK240" type device, it would probably be best to use the 12A version (in most cases), to avoid possibly overloading any 15A circuits you may encounter.

 

[Herm]

That's just generalization that implies that all converters are unsafe.

You are being picky