Portable OpenEVSE at 40A

[Michael Bornstein]

Glenn:

Placed an order with Amazon for the relay, unfortunately it is apparently shipped from China. Estimated delivery is April 23rd to May 9th. Do you have any of the relays on hand or do you know of another source that can get it here quicker?

Mike

 

[GlennD]

I have no relays of any type on hand. The only one I have is the spare 240VAC one that having on hand frightens my EVSE into behaving. I usually see the China shipping times are overstated.

That relay surfaced as the stock JuiceBox relay. You might see if they will sell you one.

 

[fooljoe]

I've got one sitting in my garage that I was thinking about using to convert my 240v-only openEVSE into 120/240 - sounds like what you're trying to do. I'm not itching to do this anytime soon, so I suppose you could have mine now then give me the new one when it arrives from China.

 

[Michael Bornstein]

Great

Are you coming to the gathering on 4/12?

Mike

 

[fooljoe]

Wasn't planning on it, but I live fairly close by if you want to just stop by for it. PM for details if you still need it when the date nears.

 

[Michael Bornstein]

Hi everyone.

I appreciate the offers. Val of EMW offered me one at a very good price, much better than what I am paying out of Hong Kong. Unfortunately, the folks in China offered me a low cost upgrade to Express delivery that should get the relay here by the week of April 7th, and I took it before I saw Val's offer. If things don't work out with China, I will take either Val's or fooljoe's offer.

Glenn, I will place an order with OpenEVSE this evening, Should I get the DIY kit (which is completely unassembled), or the Quick Kit (which is partly assembled)? What about glands? OpenEVSE has two different sizes, which should I get, or is there another source? The one you have on my set also has kink preventer, where do I get that? I am also planning on getting a 4' 14-50p cord. The only other part needed from them are the GFCI coil and an RGB display with RTC. Where do I get the power meter and the escutcheon and button? Do you want the RTC as a DIY kit, Quick Kit, or assembled?

BTW, I assume that the box is a standard 6x6x4 junction box.

Mike

 

[ehelmholtz]

Mike,
An easier way to do this would have been to buy a 40A relay like the one I used and replace it with the 40A contactor that Glenn used for your OpenEVSE. It would have been much quicker and much less expensive - just a suggestion.

 

[Michael Bornstein]

The point of the exercise was to get a smaller EVSE board so that one could fit a 12V supply for the relay so that the system would reliably run a 120V. Your idea may work (I am unsure of what relay you use), but unfortunately i have already ordered the 80A relay from Hong Kong.

 

[Michael Bornstein]

Glenn:

I am still not able to find the escutcheon at Digi-Key. Must have copied the wrong number. Please send me the correct part number, and also the number for the pushbutton if you think I should get it from them.

Mike

 

[GlennD]

The LCD escutcheon that I use from Digikey is a PRO250B-ND. It is the surround without a window. I usually use a cut piece of some window plastic I got from Home Depot to put underneath.

I have also used an escutcheon that I printed out from thingiverse.com but it requires a much more precise hole since it has tiny edges. I usually print it in gray ASB so if your lens cover is gray that is the printed one. If it is black then it is from Digikey.

 

[GlennD]

I just checked and the O on the label is really a D. The number is PRD250B-ND. I went back and got the source as well as the STL file from thingiverse. I can now print acceptable escutcheons instead of buying them.

 

[ehelmholtz]

...I need to do an experiment on JESLA to see what happens with a NEMA 5-15 installed with 240 volts present. Will it deliver 12 amps (the signal from the NEMA 5-15 adaptor on a JESLA) at 240 volts (120 volts on each L1 and Neutral) for a total of 2.88kW, or about 6 miles an hour.

Good news for people with Tony's Jesla or Tesla UMC conversion. He reports that the Tesla UMC adapters NEMA 5-15 and 5-20 both work at 240v, giving continuous 12A and 16A respectively. This means that it can be used with a quick 240 device.

Remember, this was one of the reasons why I sold my Tesla UMC conversion and made this portable open EVSE. Still, the openEVSE remains more versatile than tesla umc conversion even if not as pretty. For example, I can set the openEVSE to give pilots signals at will e.g. 14A, 18A, 20A etc. This is particularly helpful when not charging for more than three hours at a time.

 

[ehelmholtz]

Here's another example of how useful an adjustable current EVSE can be. In San Diego, the temperature has been unusually hot and it got up to 81F in my garage (according to the car) during the day and by midnight it was at 79F. I kept the car on during the day at work and in the evening after work. By midnight, the car was turned off but I wanted charging to start; I only drove 30 miles the whole day so charging at my usual 240V @40A, it would have taken 1.5 hours. However, I wanted the car to be actively charging to keep the TMS active. Using the 120V charging option would have meant not having a full battery for my drive in the morning. So, I changed the current on my OpenEVSE from 40A to 10A. This increased charging time to 5.5 hours - using up the time that SDGE has for super off-peak and having a full battery for 6 AM.

 

[ehelmholtz]

I recently built another portable 40A OpenEVSE in a 6x6x3.5" case; it works on 120V/240V with current adjustable from 6A in 1A increments up to 42A. There are some differences which I think are improvements. Firstly, I opted for a similar case but with a non-transparent cover so that it doesn't attract attention. The LCD and control button are inside so the top cover did not need to be drilled for a button. Secondly, in the first iteration, I used a Magnecraft W199X-7 DPST-NO, 12VDC coil, 40A which worked but ran a bit warm (perhaps too warm) at 40A; therefore, for this build, I decided to try a no-name Chinese made DPDT relay listed as 80A with a 12V coil (I would not run it at 80A cos it doesn't look anywhere beefy enough). It's bigger than the Magnecraft 40A one but still fits in the same case. Thirdly, instead of the Leviton ITT J1772 at 75A or the 30/32A, I bought one of Tony Williams' 8 conductor small diameter J1772 cables; it's very lightweight and has 12AWG conductors that can be combined to allow 40A current through. Here's a couple of photos:

I really like this second iteration. The new box looks more discrete and professional I think; I also like the placement of the power and J1772 cables at 90 degrees to each other. The new relay runs well at 10KW without getting excessively warm (I set max current to 42A). I like Tony's specially made 8 conductor wire a lot for it's portability but do have some worries about closing the garage door or car door on it because it is not as robust as the Leviton/ITT cables.

 

[DevinL]

I'm about to embark on this 40A OpenEVSE adventure as well. Here's my parts list so far - is there any glaring omission here? Also, I had trouble finding 40A/250V fuses and fuseholders. Will the ones I've specced here work?

OpenEVSE Plus v2 Combo with LCD (Quick KIT)
OpenEVSE $169.00 x1
http://openevse-store.myshopify.com/products/openevse-basic-combo

GE WX9X35 4-wire Range Cord (4ft)
Amazon $15.91 x1
http://www.amazon.com/General-Electric-WX9X35-4-wire-4-foot/dp/B004LYLP7I/ref=sr_1_3?ie=UTF8&qid=1401408779&sr=8-3&keywords=50+amp+range+cord

J1772 Plug/Cable Assy - 40A (15ft)
QC Power $130.00 x1
http://shop.quickchargepower.com/product.sc?productId=8&categoryId=1

JQX-62F 2C 80A 250V AC High Power Relay
Amazon $27.71 x1
http://www.amazon.com/Coil-28VDC-Power-Relay-JQX-62F/dp/B008422H48/ref=sr_1_8?ie=UTF8&qid=1401409981&sr=8-8&keywords=JQX-62F

40A 250V Fast-Blow Fuse (5 pack)
Amazon $5.39 x1
http://www.amazon.com/Qty-Fast-Blow-Fuse-AGC40A-AGC40/dp/B004QIUD72

Fuseholder 1/4"x1.25" (300V/30A)
DigiKey $1.13 x2
http://www.digikey.com/product-search/en/circuit-protection/fuseholders/655422?k=F1497-ND

Aluminum Grounding Bar
Home Depot $4.77 x1
http://www.homedepot.com/p/Blackburn-Aluminum-Ground-Bar-Only-IBT3AB-B1-10/202786635#.UYEzaaKyD8I

Metal Pushbutton LED Ring
Adafruit $4.95 x1
http://www.adafruit.com/products/481

5.9" L x 5.9" W x 3.5" H NBF-32010 Box
DigiKey $11.60 x1
http://www.digikey.com/product-detail/en/NBF-32010/377-1765-ND/2328537

Thanks!

 

[pchilds]

If you wire with #8 or larger wire, there is no need for fuses. The fuses are to protect the wiring in your EVSE.

 

[GlennD]

JQX-62F 2C 80A 250V AC High Power Relay
Amazon $27.71 x1
http://www.amazon.com/Coil-28VDC-Power- ... ds=JQX-62F

You want a 12V coil or if you are going for 240V only, a 240Vac coil or simpler, a 12V coil. The Qianji relay comes in many coil voltages.

Fuses are not really something you want to use for a fixed EVSE. They are for a portable unit where you do not know how much current is available. It will work better with the proper circuit breaker. Remember fuses and circuit breakers need to be larger for an EVSE since it is considered a continuous load. For a 40A EVSE to charge a RAV4 EV then the breaker needs to be a 50A breaker. The most current for a 40A breaker is 32A (80% of 40A).

 

[DevinL]

JQX-62F 2C 80A 250V AC High Power Relay
Amazon $27.71 x1
http://www.amazon.com/Coil-28VDC-Power- ... ds=JQX-62F

You want a 12V coil or if you are going for 240V only, a 240Vac coil or simpler, a 12V coil. The Qianji relay comes in many coil voltages.

Fuses are not really something you want to use for a fixed EVSE. They are for a portable unit where you do not know how much current is available. It will work better with the proper circuit breaker. Remember fuses and circuit breakers need to be larger for an EVSE since it is considered a continuous load. For a 40A EVSE to charge a RAV4 EV then the breaker needs to be a 50A breaker. The most current for a 40A breaker is 32A (80% of 40A).

That makes sense. I will use a 50A breaker instead then. I do intend to use this as a portable unit and not a fixed EVSE. The only time it will operate in a fixed form will be off a 20A circuit so I'll dial it down accordingly.

Should I be looking for a relay like this? http://www.amazon.com/Coil-28VDC-Power-Relay-JQX-62F/dp/B008422H48/ref=sr_1_3?ie=UTF8&qid=1401480498&sr=8-3&keywords=jqx-62f+2c

Thanks pchilds and Glenn for the help!

 

[nsayer]

You can use line powered contactors with OpenEVSE, but you'll need a contactor adapter to allow the 12VDC relay outputs of OpenEVSE to switch 208/240 volts for the coil.

They're $7.50 plus shipping from my store - http://store.geppettoelectronics.com

 

[ehelmholtz]

I'm about to embark on this 40A OpenEVSE adventure as well. Here's my parts list so far - is there any glaring omission here? Also, I had trouble finding 40A/250V fuses and fuseholders. Will the ones I've specced here work?

Hi DevinL! It's good to see old faces from the LEAF forum.
It looks like your build is almost identical to my second one above. I have a few comments. First, you don't need the OpenEVSE kit because it includes 2 relays that you won't use. The J1772 cable from Tony is good for a portable EVSE and I think that the 15' length you chose is good cos mine is 25' and gets a little warm. I agree with others that fuses are not needed even for a portable EVSE with the considerations as noted by Phil and Glenn above. You can see that I don't have fuses in my build. If you want to use fuses, you'd be best to find screw on connectors rather than the quick connect ones that you linked to above; they were the failure points in the reference EVSE builds that Chris & friends had when used at 30A. The other option is to use a breaker in your EVSE instead of a fuse which some have done. With regard to the relay to use, you have a few options. Using a relay with a 12V coil allows you to drive it with the openEVSE board and use it at 120V or 240V. The first one I built used a 40A DPST from Magnecraft but as others point out, for use longer than 3 hours, it should be limited to 32A. My latest build uses a Chinese DPDT relay at so called 80A (JQX-62F) which is the same one that Glenn and Val @ EMW use. Most serious electrical types hesitate to use relays in applications that are more than 30A and prefer to use line powered relays or contactors; this is what's done in commercial EVSEs usually; of course, to use this you usually need another relay to turn the contactor on or you can try Nick Sayer's new driver board - it looks well designed. Finally, the relay you linked to is fine except that it's nearly twice as much as what you would pay from eBay. Here is where I got mine for $15. JQX-62F 12VDC