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EVDRIVER
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Re: I designed and built a 'better' granny charger ('11 leaf)

Thu Apr 19, 2018 4:18 pm

arnis wrote:GFCI should be in the main house supply box anyway. Therefore location of disconnect relays do not matter.

People are whining so so much but almost nobody has ever died before and after that standard.

In years of EVSE use, I've never had it trip due leakage. And I've never heard it happens with others as well.
And I live in a "hell" climate in terms of moisture. Now if relay is moved closer to the handle, it changes NOTHING
in terms of leakage possibility.

Bring me some examples of real problems as well if you are so so sure that disconnect inside the handle design is
in any way dangerous (after it has been waterproofed).
If you can't explain it to to me, you don't understand it well enough.
Actually, it was more like "You do not really understand something unless you can explain it to your grandmother".



I know the standard, I do understand it, Read it and test your unit, see if it meets the standard. EV cables have disconnect specs, GFCI sensitivity specs, etc. If you are saying your home built unit has never tripped that means nothing or means it may have the wrong sensitivity or not even work at all. Where did you get the standard? Did you purchase the full standard with all the specs. Do you know that the EVSE must disconnect at the wall within XX milliseconds or removal. Do you understand why? Your premise that no one has died is ignorant for several reasons one that they don't commercially sell your unit and also you don't know that as a fact. How many people do your think have died working on a LEAF that do not work for Nissan? Do you know of any or heard of any people? I know of one for sure and a possible second. Those deaths are often not made public for many reasons. Bet you did not know that but it's true. How many pets do you think chew through EVSE cables in garages every year? You may be shocked pardon the pun. Who about cables cut by lawn mowers or frayed and energize garage doors? I've seen this more than once. Consumers do stupid things with charge cables and that is why they built this standard. I'm not going to convince you that it makes sense for many reasons just because you disagree. If you are sure your unit works correctly then test it, there are testing protocols, call Intertek or UL. see what you can get.

arnis
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Re: I designed and built a 'better' granny charger ('11 leaf)

Fri Apr 20, 2018 7:50 am

Relay position (and whole electronics board location) has nothing to do with chewing cables.
When vehicle is charging, whole system is energized. Both sides.

Like I said, household must be protected. All that chewing and dropping into puddle - that is all
irrelevant.

Whatever design is used, it's way better than direct cable. Like with EVERY other device.
For example, my pressure washer I use outside to wash my Leaf every week.
Adding all kinds of stuff changes little when there is RCD in the main box.

Yea I read the standard.
PS, it's not my design.
Short range EVs <30kWh -- Medium range: 30-60kWh -- Long range: >60kWh
Charging: Trickle <3kW -- Normal 3-22kW -- Fast 50-100kW -- Supercharging >100kW

mux
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Re: I designed and built a 'better' granny charger ('11 leaf)

Sun Apr 22, 2018 5:27 am

EVDRIVER wrote:If the relays are not at the mains side (not just the length) it defeats one of the main safety principals of the EVSE, to cut the power at the source side so there is no live power on the line to the car when charging stops or during other other events, there are other issues I can see that are pretty much a potential safety hazard as well. Just like any other safety device I suppose you can make it smaller and unsafe, like stripping the insulation off an extension cord and wrapping it with scotch take to save space. This unsafe design was already done and sold in the EU a long time ago and never sold here for that reason.


Just noticed that this thread was still active, and even though there has been some discussion afterwards I'll just respond to the first instance of this criticism: No.

The original, still valid, SAE J1772 standard from Aug 2001 does not include any requirement for the maximum distance between the AC mains plug and the EVSE. I'm baffled, and I've been searching related documents to see where this requirement comes from. The standard includes requirements to adhere to UL 2202 (EV Charging System Equipment), UL 2231 (Personnel Protection Systems for EV Charging Circuits) and UL 2251 (Plugs, Receptacles and Couplers for Electric Vehicles section 8).

UL 2251 only talks about coupler safety (and very generally at that) and UL 2231 only talks about circuit-level safety devices, not physical stuff.

I can't get my hands on a full copy of UL 2202; it seems to be not just very expensive to purchase, but also only for purchase using payment methods I don't have (e.g. credit card). All I can imagine is that somehow this document contains a reason for the short length. It must be, it's nowhere else.

Additionally, I skimmed through a bunch of SAE committee notes in search of this requirement, and it's never mentioned. It's also completely unmentioned in any certification test for SAE J1772 or any of the IEC standards on EV charging (e.g. IEC 61851).

Now, here's my conjecture. In all standards, all of the implementation details are left up to the manufacturer of the EVSE or cable. Drive-over safety is a big one, and that seems to be solved by a combination of the short AC mains cable section, a rugged connector design and lots of potting compound and thick, shielded cables. But again, no mention anywhere of a requirement to disconnect the long end of the cable from mains or anything like that. This is an implementation detail that does not come up either in the main spec, most auxiliary specs nor in committee minutes.

If anyone has more information on this or can shed light on this issue, I'm very interested. Because so far it seems like all the reasons people give for the tiny wire hanging off a big brick-shaped EVSE is conjecture on their part, not quotes from the spec. To the point that I was convinced all the people talking about this were right and it had to be *somewhere*, so I just declared my solution non-compliant.

Main SAE J1772 spec

The SAE J1772 rev 2009 standard may have added some more constraints, but again - a bit of a black hole there. I can't seem to find that spec anywhere, not even for payment. Regardless, it necessarily has to be backwards compatible and only aimed to supersede J1772-2001 for multiphase and DC charging standards, not the old level 1/2 stuff.

This stuff is driving me nuts. Why are these standards not open and easy to ready?

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EVDRIVER
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Re: I designed and built a 'better' granny charger ('11 leaf)

Sun Apr 22, 2018 6:45 am

Becase UL is a private company lobbied by insurance companies that acts like a government agency. They force you to pay high fees for certification and some municipalities require UL approval for use which is a racket. The UL standards for testing are one way they make money. In many ways UL is a joke because in many cases to test to their standard you need to pay fees to get it first to even know if you comply let alone can pass.

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Re: I designed and built a 'better' granny charger ('11 leaf)

Sun Apr 22, 2018 1:12 pm

arnis wrote:Relay position (and whole electronics board location) has nothing to do with chewing cables.
When vehicle is charging, whole system is energized. Both sides.

Like I said, household must be protected. All that chewing and dropping into puddle - that is all
irrelevant. ...


Not so. There are many millions of homes in the US that do NOT have ground fault interruption at the breakers. Possibly the majority. You may think they should, but they do not. Maybe in Estonia, but not here.
I noticed you're still working with polymers.

arnis
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Re: I designed and built a 'better' granny charger ('11 leaf)

Mon Apr 23, 2018 6:50 am

Same here. But EVSE is not a device that should "save lives". It should charge vehicle. Safely.
Charging safe for vehicle and operator. Not for rodents and children.
And again, with or without safety device in the main box, whole cable is live when vehicle is charging.
Short range EVs <30kWh -- Medium range: 30-60kWh -- Long range: >60kWh
Charging: Trickle <3kW -- Normal 3-22kW -- Fast 50-100kW -- Supercharging >100kW

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EVDRIVER
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Re: I designed and built a 'better' granny charger ('11 leaf)

Mon Apr 23, 2018 8:47 am

arnis wrote:Same here. But EVSE is not a device that should "save lives". It should charge vehicle. Safely.......
.



Nice rhetorical statement. You should market your product with that on the box.

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Re: I designed and built a 'better' granny charger ('11 leaf)

Mon Apr 23, 2018 9:04 am

mux wrote:The original, still valid, SAE J1772 standard from Aug 2001 does not include any requirement for the maximum distance between the AC mains plug and the EVSE. I'm baffled, and I've been searching related documents to see where this requirement comes from.

FWIW, as far as the US goes, the National Electrical Code covers EVSEs in Article 625. Section 625.22 requires an EVSE to provide a personnel protection system, and further requires that if the EVSE is cord and plug connected, the relay needs to be within 12 inches of the plug. Article 625 first appeared in the NEC in 1996, and that version had the same requirement.

Cheers, Wayne

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Re: I designed and built a 'better' granny charger ('11 leaf)

Mon Apr 23, 2018 9:48 am

Well, there it is. I guess it's a US-specific thing then, because this is not harmonized to IEC standards.

arnis
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Re: I designed and built a 'better' granny charger ('11 leaf)

Mon Apr 23, 2018 2:26 pm

It's just something written somewhere. God forbid relay to be 13" away from the plug :lol:

Up to this date, red turn indicators kill more people in US than all EVSE's in the world.


Your logic is brilliant and well thought out. You should design HV power electronics and personally test all your designs.
Short range EVs <30kWh -- Medium range: 30-60kWh -- Long range: >60kWh
Charging: Trickle <3kW -- Normal 3-22kW -- Fast 50-100kW -- Supercharging >100kW

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