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Discussion Starter #1 (Edited)
What do you do when your Voltec 240V EVSE dies? Instead of throwing it away, you could remove the circuit board and replace it with OpenEVSE and other off-the-shelf components. I am not an Electrical Engineer so I invite those who are to comment on any errors in the schematics, etc. below.

I tried to make the OpenEVSE schematics a bit easier for those who are handy with basic tools and a soldering iron, but like me are not a electronics expert. Caution must be exercised of course when working with live 240V current as it can be a killer (literally). I provide my notes and pictures, etc. below as-is, with no warranty as to fitness of purpose, suitability for your use, yadda, yadda. Consider this an experiment, not a commercial product. That said, many have built their own EVSE in a similar way.

I have not done one of these conversions before. Special thanks to our own Fishhawk for being a Voltec conversion pioneer, and for providing some photo's, technical help, and inspiration. Also thanks to Chris Howell at OpenEVSE http://code.google.com/p/open-evse/ who helps supply the boards, parts lists, schematics, etc. that this is based on.

Image 1. Gutted Voltec (mine) with some labels.
Image 2. Mounting Plate. A "dress pattern" based on Fishhawks home-brewed aluminum mounting plate.
Image 3. "OpenEVSE Plus" schematic. I added color coded wires, as well as the wiring for the Voltec J1772 cord handle light, and the Voltec front cover LED wires.
Image 4. Finished Project. A semi-realistic illustration of Image 2 and Image 3 combined.
Image 5. Fishhawk's Voltec Conversion with labels. He used an earlier OpenEVSE board, so his wiring is slightly different, as are the positions of his fuses. See http://gm-volt.com/forum/showthread.php?18953-SPX-Voltec-240V-charger-just-failed.&p=216844#post216844

Voltec-Gutted 72.jpg Voltec-OpenEVSE-MountPlate.jpg Voltec-OpenEVSE-Schematic.jpg Voltec-OpenEVSE-Wiring-Illu.jpg Voltec-OpenEVSE-(fish-72).jpg


Dead Voltec to Live EVSE Parts List

Thanks again Fishhawk and Chris Howell at OpenEVSE

Total Cost ~$273
(plus one dead Voltec)

Parts from OpenEVSE Project (Chris Howell) Total: $175 incl shipping
Parts from Digikey: Total: $51.42 incl shipping via US post
http://code.google.com/p/open-evse/wiki/EVSE_EV_ChargeAmerica_Upgrade

Quantity | Part Number | Description | Unit Price | Extended Price
1 | PB486-ND | RELAY GEN PURPOSE DPST 30A 12V | $13.03 | $13.03
1 | 582-1018-ND | TRANSFORMER GROUND FAULT WIRE LD | $10.65 | $10.65
2 | 283-2850-ND | FUSEHOLDER 1/4" 30A 250V PNL MNT | $3.51 | $7.02
4 | F1779-ND | FUSE 250V SLO-BLO 3AB 30A | $1.68 | $6.72
6 | 726308-1-ND | CONN ADAPTER DOUBLE TAB .250 | $0.94 | $5.64
1 | OF471JE-ND | RESISTOR 470 OHM .5W CARB COMP | $0.52 | $0.52
1 | OF561JE-ND | RESISTOR 560 OHM .5W CARB COMP | $0.52 | $0.52 (just in case the 470 doesn't work out)
1 | CF12JT680RCT-ND | RES 680 OHM 1/2W 5% CARBON FILM | $0.14 | $0.14
4 | 492-1108-ND | SPACER NYLON #6 SCREW 1/2" | $0.16 | $0.64 (for mounting the circuit board to the plate)

Parts from Home Depot $35.20
Parts from Menards $10.89

Parts from Radio Shack or Frys Electronics (if not ordered via Digi-Key above)
  • 680ohm resistor (for Handle LED).
  • 560ohm or 470ohm resistor for front Cover LEDs. 1/2 watt resistors may be good enough. (We are a bit unsure, but think the 470 ohm is what is needed).
  • 10MM Standoffs (pkg of four ~1/2" spacers with screws) $3.78 (Also avail at Frys Electronics, $1.89 Frys#6473562)
Other Parts

  • Aluminum, steel or plastic mounting plate (self supplied and fabricated)
  • Wire. I used #10 copper for the twin 120V power lines (but #12 would be fine and easier to work with), and #18 for the relay to OpenEVSE Plus (same wire as used inside 4' fluorescent fixtures)
  • Screws for mounting the relay, OpenEVSE Plus. #6 machine threaded, 1/2"-3/4" long.
NOTES
1. The OpenEVSE can take either 120V or 240V in (it autoswitches), so 120V from a wall outlet can be used to test with the EV Simulator. I plan on using it for 240V only via a plug.

2. Looks like pin #1 on the Relay is the correct connection point. According to Chris Howell, "One of the pins on the relay output is tied directly to +12v so that would be a good place to tie in." :) Feedback welcome.

3. The front panel LEDs are tricky. The way they are connected in this schematic, the LEDs only show power, not any state information. A 9v battery, resistor, and test probes were used to test the front panel LED pins until a set of pins made both LEDs light up. In the Voltec front panel, it looks like #3 pin in the top row (L to R) connects to the +12V DC, and #1 in the bottom row connects to GND. The LEDs may not light if the unit is plugged into a 120V GFCI outlet rather than 240V.

Using a wiring harness from a pair of speaker-PC motherboard connectors (found at a PC shop, possibly Radio Shack?), the pin was slipped out of the black plastic, and slid into another hole to get the pins to line up as needed. The ground wire was connected to ground on the OpenEVSE, and the red wire was connected to a 680ohm resistor (470 ohm may be better: brighter LED) soldered to the same copper +12V pad as the J1772 cord handle flashlight 680ohm resistor. It's this front panel LED resistor I thought should maybe be a 560 or 470ohm resistor, instead of the 680ohm.

4. The OpenEVSE project also offers a cool RGB LCD display kit. That is an options for those who want more than two green LEDs on the Voltec front cover. The LCD can provide more detailed data. See the OpenEVSE website for details. If you have used this with the Voltec and can provide step-by-step how to photos, please let me know.
 

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Discussion Starter #2 (Edited)
Additional files, including PDF's of some of the above.
Voltec-openEVSE-Front-72.jpg View attachment Voltec-OpenEVSE-MountPlate.pdf , View attachment Voltec-OpenEVSE-Schematic.pdf , View attachment Voltec-OpenEVSE-Wiring-Illu.pdf , Finished Wiring2.jpg

The last image is my finished wiring. I added a ferrite ring to the power input (mostly because I had one and saw that others using openEVSE employed them. I also got some "Crimp Pin 0.1" male and female from Fry's Electronics. Two females for attaching the ferrite ring (below the circuit board) to the two pins on the board. And two male pins for plugging into the ribbon cable from the LED's on the front of the Voltec.

A note on heat shrink tubing: a hair dryer on hot is only marginally useful in my experience. A heat gun would work better. I used a small propane touch (carefully, at a distance) to quickly shrink the tubing nice and tight.
 

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What's the benefit of converting a 240V Voltec?
 

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Discussion Starter #7
What's the benefit of converting a 240V Voltec?
Well, when they die 3 weeks after the 1 year warranty ends, they are basically unrepairable (by SPX) junk. This is a way to make them a functioning EVSE again.
 

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This is awesome. I'm sure I'll follow in your footsteps when my Voltec eventually craps out. The endless reports of Voltec failures on these forums do not inspire confidence.
 

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I just finished building my own Open EVSE from scratch. It would have been nice to have a broken Voltec charger to start from. I looked through the schematic and pictures and I only see 2 errors. The schematic shows running both LEDs from the hot wire going to the relay. That means the flashlight LED will only light when the car is already charging. Not very useful for plugging it in. The other item was just a wording mistake that says the LED provides more data. It's the LCD that provides more data.
 

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Well, when they die 3 weeks after the 1 year warranty ends, they are basically unrepairable (by SPX) junk. This is a way to make them a functioning EVSE again.
Ah, yes that seems like a good reason ;)

I know many have just had their fuse blown. I hope if/when my goes, it's just a fuse. So far I've had it two years and its working well (knock on wood)... Warranty expired a year ago as I installed it myself, not through SPX.
 

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Thanks, Steverino, for putting my rough "prototype" into a practical form that others can use. I always wanted to do the drawings you did, but just never got around to it. Glad you were able to fill in the missing pieces.

As Ron in Omaha points out, the flashlight will not work unless the relay is energized, which doesn't help you when trying to plug in.
 

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As an EE, I see the diagrams well done. Assembling and wiring is a different thing. Getting a 240 VAC shock is only possible if you voluntary touch both live feeds at the same time. Touching only one is 120 VAC, which is the same danger as a regular home outlet. If you wire everything carefully with the main power off (breaker off), and have someone check the wiring before applying power, you should have no problems.

What can harm or kill you is the the amount of current flowing across your chest. So if you do need to work near live wires (only licensed electricians have the training to do so!), keep your free hand in your pants pocket, so if you are accidentally shocked, it will not harm you much. I worked with high voltage vacuum tube TV and radio sets as a student and I have received my sample of shocks. But if you want to work safely, wear two sets of disposable gloves (double layer prevents tears) or a good set of electrician gloves. Most men don't work with gloves because they can't feel the work, but I do use gloves (and I really am an EE with over 50 years working with electricity) and I prevent unwanted surprises.

Have fun and keep the Volt charged up!
 

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Discussion Starter #14 (Edited)
I only see 2 errors. The schematic shows running both LEDs from the hot wire going to the relay. That means the flashlight LED will only light when the car is already charging. Not very useful for plugging it in.
Thanks, Ron. So the flashlight LED should be connected to the #0 post on the relay instead of the #1 post? Someplace else?

LED typo changed to LCD.

Getting a 240 VAC shock is only possible if you voluntary touch both live feeds at the same time. Touching only one is 120 VAC, which is the same danger as a regular home outlet. If you wire everything carefully with the main power off (breaker off), and have someone check the wiring before applying power, you should have no problems.
Thanks for that, Raymondjram. Work with the power off is good advice that should be followed by anyone attempting this. The warnings are part of the OpenEVSE schematic, and people being people, I thought it best to repeat it.

As Ron in Omaha points out, the flashlight will not work unless the relay is energized, which doesn't help you when trying to plug in.
I'm happy to contribute what I can (the drawings), but I will need some guidance on the correct flashlight connecting point.

I am concerned that the LEDs go from the 12V to ground. If you have a GFCI in the supply path (i.e. when using an outside 120V outlet) the LED current may be enough to trigger it.
Is there a solution? It sounds like at worst, the Voltec front panel LEDS may not light green, but the car will still charge. Even though the OpenEVSE is capable of using 120V, my interest would be 240V. This LED "solution" is not ideal, as it is really only a power on indicator. It won't display faults like the OEM. Of course, the available RGB LCD kit for the OpenEVSE will do that and a bit more. See http://code.google.com/p/open-evse/
 

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Steverino:
You may be OK on the +12 volts. A post in the OpenEVSE forum stated that "One of the pins on the relay output is tied directly to +12v sho that would be a good place to tie in..."

That seems to indicate that the designer ran the +12v to one side of the relay, and grounded the other side when he wants to operate the relay. That is common practice in the ATM and bank equipment world that I work in, so it rings true to me. Of course he didn't say WHICH pin so you've got a 50/50 chance to get it right the first time. But it will either light or not, you won't blow anything up.
 

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Steverino:
You may be OK on the +12 volts. A post in the OpenEVSE forum stated that "One of the pins on the relay output is tied directly to +12v sho that would be a good place to tie in..."
That would great news. I know that Chris Howell has done a fabulous job of shrinking OpenEVSE, and if you can get a pin to do double-duty, then you don't need the board real estate for another pin.
 

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Discussion Starter #17
Steverino:
You may be OK on the +12 volts. A post in the OpenEVSE forum stated that "One of the pins on the relay output is tied directly to +12v sho that would be a good place to tie in..."

That seems to indicate that the designer ran the +12v to one side of the relay, and grounded the other side when he wants to operate the relay. That is common practice in the ATM and bank equipment world that I work in, so it rings true to me. Of course he didn't say WHICH pin so you've got a 50/50 chance to get it right the first time. But it will either light or not, you won't blow anything up.
Not blowing up is good, haha.

So it seems the flashlight needs to be connected to either pin #0 or pin#1 on the Relay (one will work, one won't)?

Given that all I have at this time is an intention of doing this conversion at some point in the next few months and have none of the components except a gutted Voltec, I can't really test this at the moment. Maybe someone else will get there first!
 

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Don't forget to add a resistor to the wire that comes from the charge cord!
 

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Discussion Starter #19
Don't forget to add a resistor to the wire that comes from the charge cord!
Good point. There is a resistor labeled as "R1" in the Schematic and the Illustration. There is another "R2" for the front panel LEDs.
 

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I'm curious about the insurance legalities. There's obviously no UL seal.

Does it matter if the EVSE is hard wired and not plugged into an outlet? I built some ham rigs, but they were never hard wired.

Are you required to have your setup inspected by the local building inspector?

You don't want to have this discussion after the insurance company disallows a claim.
 
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