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Discussion Starter #1
I did a quick search for j1772 in the forum and didn't find this answered anywhere, so I'm asking here.....

I found a "schematic" on wikipedia for the signalling on a J1772 plug. But I know that the square wave signal isn't required for <16amps charging. Has anyone made a super simple charge cable DIY? What is the basic signalling required to simply charge the car from 120/240? The cable and connector are $170 or so on ebay, so it might just be easier to buy a portable cable such as https://duosidaevchargers.com/products/220v-level-2-fast-charger-16-amps?utm_medium=cpc&utm_source=googlepla&variant=39760207557&gclid=Cj0KCQiA4bzSBRDOARIsAHJ1UO5sSs-WhXVxdom9zPJkDSsNK_EfN0QwTQnqafgf1zhpl8_UHH-9pT8aAiItEALw_wcB
 

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I bought a cable much like that, I think I paid around same figure for it.

When it arrived it was in a nice carrying case, I plan on using for the 110 charger when I leave it in the car.

At my house I have a line running out to the garage that was put in for an electric overhead heater( I did this last summer when I was getting ready to buy an EV) it had the correct breakers although at this moment I can't recall what they were.

I installed a 220V outlet on it, this outlet is what I plan to use on the Bolt when I bring it home this afternoon.

I don't have the company's card with me, sorry if I remember when I get home I will add it to the thread.
 

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The individual parts might cost you more than the built wire, then if you bought just the parts if one of them failed....

Its fine if you have access to the parts at wholesale prices, and the knowledge to build it, then it might be worth building it yourself.
 

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Discussion Starter #6
Question... for level 1 charging, can you simply put 110/220 on the power pins of the J1772 jack and the car will just take off and charge?
 

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Question... for level 1 charging, can you simply put 110/220 on the power pins of the J1772 jack and the car will just take off and charge?
No you need a pilot signal and a contactor in the EVSE as well. If the vehicle senses power on the pins without a valid pilot it will lock down due to faulty EVSE equipment.
 

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No you need a pilot signal and a contactor in the EVSE as well. If the vehicle senses power on the pins without a valid pilot it will lock down due to faulty EVSE equipment.
Not sure about the pilot (for low amps), but you do not need a contactor. The contactor in my DYI unit died last night. After I had bypassed it (to make sure it was the cause of the failure) the car (an Opel Ampera but still) charged fine. At 24 amps as dictated by the pilot pin. It does not lock up or anything.

When I say you don't need it, I mean 'technically speaking'. Safety wise, obviously it is a different issue.
 

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I assume you had the pilot, but if the pilot goes away and the power stays, the car "should" shut down the charger. If not... yikes!
 

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I assume you had the pilot, but if the pilot goes away and the power stays, the car "should" shut down the charger. If not... yikes!
Of course it does. Pilot controls how much power is drawn. If pilot says 0, car will take 0. As a matter of fact, fro what I understand car takes zero if pilot says anything below 6 A. That power is still there does not matter.
 

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Discussion Starter #12
Not sure about the pilot (for low amps), but you do not need a contactor. The contactor in my DYI unit died last night. After I had bypassed it (to make sure it was the cause of the failure) the car (an Opel Ampera but still) charged fine. At 24 amps as dictated by the pilot pin. It does not lock up or anything.

When I say you don't need it, I mean 'technically speaking'. Safety wise, obviously it is a different issue.
Good info.... I think there are two reasons for the contactor... 1)longevity of the plug. By shutting off the power the pins don't arc. 2)safety... w/o a car present the cord is absolutely safe.
 

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Good info.... I think there are two reasons for the contactor... 1)longevity of the plug. By shutting off the power the pins don't arc. 2)safety... w/o a car present the cord is absolutely safe.
I agree with 2). With 1) not so much. As soon as you push the button on the Type 1 plug (or unlock the type 2 plug on an Ampera E using the button on the FOB), the pilot pin is cut off and the car stops charging. No charging => no current flow => no arching. The absense of the current flow is not just because the contactor is disengaged. Think about unplugging your dishwasher. That doesn't cause arching either, unless you forgot to urn off the dishwasher before unplugging it. Arching does become an issue when you use a portable EVSE and unplug it grid side while charging is still ongoing.

BTW: if 1) did apply, the arching would have just been moved from the plug to the contactor. IMHO, in the long term contactors are not to happy with that either.
 

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Discussion Starter #14
BTW: if 1) did apply, the arching would have just been moved from the plug to the contactor. IMHO, in the long term contactors are not to happy with that either.
Correct... for example, the contactor on my house's heat pump welded closed and had to be replaced twice in the life of the unit. Anyway, thanks for the info guys, I'm learning.... and at this stage I'm learning what I need to learn. :)
 

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On the OpenEVSE I built, the contactor seems to mainly provide the function of the built in GFCI and the thermal protection functions, and it also monitors for a stuck or welded contactor and inhibits the pilot if it finds a fault. I'd have to dig into the code to see if does anything else, but that's all I can think of off hand.

edit: I did find the six self tests/checks it does. All the failures should drop the pilot and open the contactor, well except the welded contactor check of course, not much it can do about that other than drop pilot. AFAIK these checks exceed the required safety checks at least on some fronts, it even supports the old lead acid vent required signal that is in the J1772 standard.

GFI Self Test: Enabled
Ground Monitoring: Enabled
Stuck Contact Detection: Enabled
Temperature Monitoring: Enabled
Diode Check: Enabled
Vent Required: Enabled
 

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I assume the code also checks for the pilot signal being pulled down to less than 6 volts by the car (or as a matter of fact to -12 to +6) before activating the contactor? This is how the evse know the car is actually willing to accept power and not just hooked up.
 

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Now I realize, you already mentioned diode check. Diode check can only pass when a car is hooked up, as the diode too be checked is in the car.

Tesla's will not charge using evse's that do not implement the diode check, btw.
 
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