Do It Yourself: 240v from two 120v sources

[hieuous]

i get it, based on my responses i sound like an idiot that doesn't know what she's getting herself into.

no i havn't tested it like that yet, i will when i get back from drill in two weeks. I'm going to write a DIY up. step by step and explain everything so nobody is confused when they read this thread.

like i said, i actually know what i'm doing. even if my questions make me come off as stupid.

 

[ebill3]

i get it, based on my responses i sound like an idiot that doesn't know what she's getting herself into.

Of course not - nobody suggested you are an idiot. But, based on your questions, many, myself included, were concerned about your apparent lack of knowledge of basic electrical circuits.

Lack of such knowledge does not an idiot make. Very many highly qualified folks in other technical fields would not touch a 120 volt circuit with a ten foot pole. My Civil Engineer son is well qualified in his field, but I wouldn't trust him to work in my breaker panel. Another son teaches high school math and science, but calls on old dad for household electrical wiring advice.

 

[CasperNleaf]

Parts list, schematic, reference pictures, and links for this project are contained in my pdf file:
120V to 240V PROJECT (PDF)

For people new to electronics the pictures help make sense of the schematics. I've have pics of every posted 120 to 240V build to date in my PDF.

 

[hieuous]

i get it, based on my responses i sound like an idiot that doesn't know what she's getting herself into.

Of course not - nobody suggested you are an idiot. But, based on your questions, many, myself included, were concerned about your apparent lack of knowledge of basic electrical circuits.

Lack of such knowledge does not an idiot make. Very many highly qualified folks in other technical fields would not touch a 120 volt circuit with a ten foot pole. My Civil Engineer son is well qualified in his field, but I wouldn't trust him to work in my breaker panel. Another son teaches high school math and science, but calls on old dad for household electrical wiring advice.

Im myself studying mechanical engineering but I'm still very new to it. I'm just glad all of you guys are so welcoming and are so helpful. Even to somebody you don't know. Electric vehicles are brand new to me as I come from a long history of ICE vehicles. Last car I built was a 1973 Chevy camaro that I built and boosted in my garage. which i still have. The car before that was a Infiniti g35 that I hit 800bwhp before I sold it. and got the leaf....plus numerous other cars that I built boosted and sometimes blew up.

This is the first electric car I've ever touched so its all new but upon reading a little on relays and schematics I suddenly understood it. Its like magic.

Again. Thank you. All of you. I'll make a DIY and post here soon as soon as I come back from my national guard training.

 

[hieuous]

i used a 14 AWG ext cable...is that okay? they are rated at 15 amps each.

 

[mwalsh]

i used a 14 AWG ext cable...is that okay? they are rated at 15 amps each.

On which EVSE? The EVSE upgrade one? And, if so, did you get the 12a or 16a version?

Either way, I personally wouldn't. My 25' extension cord is 12 gauge, and my 50' one is either 6 or 8 gauge (it's been a long time and I forget which). But the longer one is more of a 240v extension cord, and only does emergency double duty. The ideal is to only need the one extension cord for the second pigtail from the device as a matter of course, finding an outlet closer to the car for the first pigtail.

 

[hieuous]

i used a 14 AWG ext cable...is that okay? they are rated at 15 amps each.

On which EVSE? The EVSE upgrade one? And, if so, did you get the 12a or 16a version?

Either way, I personally wouldn't. My 25' extension cord is 12 gauge, and my 50' one is either 6 or 8 gauge (it's been a long time and I forget which). But the longer one is more of a 240v extension cord, and only does emergency double duty. The ideal is to only need the one extension cord for the second pigtail from the device as a matter of course, finding an outlet closer to the car for the first pigtail.

http://www.homedepot.com/p/50-ft-14-3-Extension-Cord-AW62661/100661457#.Ubuwl-fVDKg" onclick="window.open(this.href);return false;

that's what i got. would it work? i havn't gotten my evse upgraded yet, i just built this yesterday but don't have anything to test it with a load.

 

[davewill]

that's what i got. would it work? i havn't gotten my evse upgraded yet, i just built this yesterday but don't have anything to test it with a load.

I have to agree, I wouldn't use it, especially anywhere near that length. You want at least 12awg.

 

[hieuous]

that's what i got. would it work? i havn't gotten my evse upgraded yet, i just built this yesterday but don't have anything to test it with a load.

I have to agree, I wouldn't use it, especially anywhere near that length. You want at least 12awg.

aw dammit. i already chopped it up. i knew i should have asked before anything.

 

[DaveEV]

14ga will be fine, just limit current to 12A and as short as tolerable. I used mine for a while with 14ga since that's what I had on hand and it was OK even at 16A with no significant warming or voltage drop, but I still replaced it with 12ga.

 

[hieuous]

14ga will be fine, just limit current to 12A and as short as tolerable. I used mine for a while with 14ga since that's what I had on hand and it was OK even at 16A with no significant warming or voltage drop, but I still replaced it with 12ga.

whats the difference between charging at 12a vs 16a?

i have both a 12awg and 14awg extension cable...the 14 awg is so pretty though, it's green!

 

[DaveEV]

whats the difference between charging at 12a vs 16a?

About 4A!

It's only applicable if you are using the EVSE upgrade - do you have one or are getting one? (although if not, I'd wonder what you're building an Easy240 for...)

i have both a 12awg and 14awg extension cable...the 14 awg is so pretty though, it's green!

Like I said, 14GA is fine for 12A - and it's even OK for 16A, as long as the run isn't too long. I certainly wouldn't use all 50 ft of your green cord at 16A - it's borderline at 12A.

What I would do is use perhaps 20 ft of the cable for the Easy240 - I would just use two 10 ft pieces, though Phil suggested that one long one sort cable is often convenient. Then get a good quality connector to replace the one you chopped off and use the rest as a regular extension cord - not necessarily for the Easy240 unless you're only charging at 12A or less!

 

[hieuous]

whats the difference between charging at 12a vs 16a?

About 4A!

It's only applicable if you are using the EVSE upgrade - do you have one or are getting one? (although if not, I'd wonder what you're building an Easy240 for...)

i have both a 12awg and 14awg extension cable...the 14 awg is so pretty though, it's green!

Like I said, 14GA is fine for 12A - and it's even OK for 16A, as long as the run isn't too long. I certainly wouldn't use all 50 ft of your green cord at 16A - it's borderline at 12A.

What I would do is use perhaps 20 ft of the cable for the Easy240 - I would just use two 10 ft pieces, though Phil suggested that one long one sort cable is often convenient. Then get a good quality connector to replace the one you chopped off and use the rest as a regular extension cord - not necessarily for the Easy240 unless you're only charging at 12A or less!

i ended up using a 12GA line extension cord that i have. it's not as pretty but it's okay. i'm going to get the upgrade done as soon as i get back but my question was; What's the real difference, does it charge faster? but would it make that much of a difference if it was at 12amps vs 16 amps?

 

[QueenBee]

i ended up using a 12GA line extension cord that i have. it's not as pretty but it's okay. i'm going to get the upgrade done as soon as i get back but my question was; What's the real difference, does it charge faster? but would it make that much of a difference if it was at 12amps vs 16 amps?

If I am following this this thread properly your question is comparing 12 amp 120 volt charging with the OEM EVSE vs the EVSE Upgrade at 16 amp 240 volt. This is a huge difference in speed. 16 amp 240 volt charging will be roughly 166% faster.

 

[ebill3]

i ended up using a 12GA line extension cord that i have. it's not as pretty but it's okay. i'm going to get the upgrade done as soon as i get back but my question was; What's the real difference, does it charge faster? but would it make that much of a difference if it was at 12amps vs 16 amps?

And, if you are asking 12 Amps vs. 16 Amps both at 240 volts, it is almost a kW difference.

My question is: Are the 120 volt circuits you are using capable of 16 Amps continuous? Most household 120 volt circuits are 15 Amps, 12 Amps continuous.

I also rent, and I know the circuits I use are 14 ga and not dedicated. When I upgraded my EVSE, the folks at evseupgrade.com queried me why I did not select the 16 Amp revision. Easy answer - as mentioned, the available circuits. I know some folks are pulling 16 Amps from a 15 Amp circuit, but that is not for me.

Twelve Amps at 240 volts is plenty quick enough for the LEAF and I sleep well. Shucks, I even charge the Tesla at 12 Amps. That only gives me 8 MPH, but the job gets done eventually.

 

[MikeD]

There is a new rule in the 2014 NEC (which will be published in the last quarter of this year) which reads (from a draft copy):

"Article 210.17 (Electric Vehicle Branch Circuit.) 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."

It is possible that it may be slightly modified for clarity's sake (I think it is unclear as written), but should otherwise remain adopted as it reads above. Because it reads "separate branch circuit" (which is not formally defined, instead of "individual branch circuit" which is formally defined as "a branch circuit that supplies only one utilization equipment"), I take this to mean "separate from any other outlets (like for lighting or plug-in appliances)" and may have multiple outlets, each only usable for EVSEs.

If my interpretation is correct, in addition to an EVSE on an "individual branch circuit", either direct wired or "cord-and-plug-connected", it would also allow a single branch circuit with, say, two NEMA 6-50r receptacles (located conveniently for EV charging), so that a single movable cord-and-plug-connected EVSE could be connected at either of these two receptacles. It would also allow two (or more) direct wired EVSEs to be on the same circuit which are controlled by an "automatic load management system", which may be available in the near future, as it is referred to in the following:

"Article 625.14 (Rating.) Electric vehicle supply equipment shall have sufficient rating to supply the load served. Electric vehicle charging loads shall be considered to be continuous loads for the purposes of this article. Where an automatic load management system is used, the maximum electric vehicle supply equipment load on a service and feeder shall be the maximum load permitted by the automatic load management system.".

Needless to say (again), the OP approach to charging is rife with safety problems, from requiring receptacles w/o GFCI protection (which may even cause permanent removal of this protection from receptacles in wet or potentially wet areas for the expediency of being able to charge), to using multiple extension cords (which become perhaps even more hazardous with repeated non-emergency use), to pushing the safety limitations of conductors, receptacles, and circuit breakers when used with EVSEs on non-dedicated circuits with other loads, or (inadvertently or deliberately), with EVSEs which can exceed 12a (or even 16a) of charging current.

 

[Ingineer]

whats the difference between charging at 12a vs 16a?

i have both a 12awg and 14awg extension cable...the 14 awg is so pretty though, it's green!

Hieuous, if you've got a few minutes, take a look at this, and be sure to also read the Electricity/Water Analogy linked on that page. It will help you get a better understanding.

-Phil

 

[cdherman]

Well, although the thread has taken a decided turn to the discussion of code, versus not code, which of course is a valid consideration, I have something back on the old thread...

I have been reading about the quick 240v topic in detail, I was interested in the posts regarding the use of a voltmeter to measure voltage drop after applying a load to the "quick 240v device". Concept being that a circuit of questionable quality would exhibit a larger V drop and signal that its not safe to use that outlet. The V drop would have to be in the form of heat somewhere in the circuit. Not a good thing.

So I decided to construct my Quick 240V device with a voltmeter, and not bother with the lights and sounds. As I began to search for an appropriate voltmeter on eBay, the cheap digital LED units always popped up first.

Then I started reading a little more and based on the specs I struck me -- an LED voltmeter would only show V across the 240V legs when BOTH were hot. So a digital voltmeter would double as a visual (light) signal that 240V was present.

I ordered a couple of these: http://www.ebay.com/itm/170846275210?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649" onclick="window.open(this.href);return false;

I put the whole pile of parts together today and I am happy to say, it works. I plugged it into a variety of circuits (I know my home wiring well, but its a bit enlightening to realize what side of the pole many branch circuits are on through happenstance), and got nothing the first couple combinations. Then, I got 243v and the voltmeter lit up. It remained blank until it got 240v, logically, since one or the other side was either a) not plugged in or b) in phase, and thus V between the two was 0.

I would do some pics, but I don't have an easy way. Suffice to say, its handy in my opinion. A light that indicates 240v (+/-) that doubles as a voltmeter.

But here is a question -- I have been reading about acceptable V drop. I see numbers of 2,3 5, even 10% being acceptable under load.

My V went from 243v under no load to 238 under 16A cont (my EVSE). It holds steady there. That calculates to just a tiny bit over 2% drop. I have a long run of wire to my garage, so I am OK with that.

But is there any rational way to decide about acceptable voltage drops?

I'd like to put a note on my device with some numbers for reference -- a sort of "do not use if V under X when plugged in" message to me for the future.

Input?

 

[DaveEV]

But here is a question -- I have been reading about acceptable V drop. I see numbers of 2,3 5, even 10% being acceptable under load.

My V went from 243v under no load to 238 under 16A cont (my EVSE). It holds steady there. That calculates to just a tiny bit over 2% drop. I have a long run of wire to my garage, so I am OK with that.

But is there any rational way to decide about acceptable voltage drops?

I'd like to put a note on my device with some numbers for reference -- a sort of "do not use if V under X when plugged in" message to me for the future.

The NEC says 3% for feeders and 5% for branch circuits is the suggested limit.

So if you come out to less than 5% (less than about 12V drop from 240V), I wouldn't worry.

If you come out higher than that, you might deem it acceptable if some of that drop is also occurring at the feeder (main breaker).

Personally, I wouldn't be comfortable for charging very long if I saw more than 5% drop unless you know you're on a very long run. Even a 5% drop at 16A you're looking at 192W of heat being dissipated somewhere - if it's in a terminal somewhere it's going to heat up VERY quickly. If it's along a long run of wire - it will be fine.

 

[hieuous]

i couldn't do it guys =(

the leaf left me stranded in a very very bad neighborhood here in vegas because i was heading to the nearest charging station. it was a very bad day for me.

i got a prius C three instead =/ i miss the torque of the leaf but this is a better overall purchase.

i still have my EVSE and my 240 volt thing i made. do you guys think people will buy it? i'll take pictures of it...