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

Sat Apr 14, 2018 6:21 am

You can't cut power "at the source". Without tripping the breaker.
This device has relays that DO cut high voltage power at the J1772 side.
And no EVSE cuts power at the source (wall outlet).
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Re: I designed and built a 'better' granny charger ('11 leaf)

Sat Apr 14, 2018 8:09 am

arnis wrote:You can't cut power "at the source". Without tripping the breaker.
This device has relays that DO cut high voltage power at the J1772 side.
And no EVSE cuts power at the source (wall outlet).



Not the outlet at the EVSE box. There is a specific reason the standard dictates a short wall cord, you must cut the power at the box. The reason is because power is never to be live on the long side of the cord under certain conditions, this is one of the PRIMARY functions of the EVSE. If the relays are not at the box with a short cord then you have defeated one of the the primary safety functions of the unit. Cutting the power at the handle only addresses the arcing issue (if done correctly) when pulling the J1772. Please explain how relays in the handle prevent the main cable from having power when charging halts, the disconnect is activated, or other faults are present? You have only created an extension cord that defeats the principal design intent of an EVSE which is safety, it is no longer an EVSE it is only a extension cord that will work on an EV with reduced safety features. What you find as "stupid" is a critical part of the design. I would guess that if your unit was tested under the standards it would also fail in other areas. There are reasons for the standard and they dictate the safety architecture of the unit.
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arnis
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Re: I designed and built a 'better' granny charger ('11 leaf)

Sun Apr 15, 2018 1:09 am

Why should EVSE be excessively more safer than... let's say... toaster, hair dryer or laptop charger?
Just have a functional RCCB and 16A breaker at the source and in case of any fault, no lives will be hurt.
If there is no such things for outdoor outlet, then EVSE is not the reason to blame.
One can die with OEM granny charger while plugging/unplugging granny charger to the outlet even
though no vehicle is connected. It's just slightly better to have that control box earlier in the loop.
But in terms of real "lives saved" - unmeasurable results. Compared to RCCB before outdoor outlet.

This handle charger must be waterproofed. Then it is good enough.
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Re: I designed and built a 'better' granny charger ('11 leaf)

Sun Apr 15, 2018 8:20 am

arnis wrote:Why should EVSE be excessively more safer than... let's say... toaster, hair dryer or laptop charger?
Just have a functional RCCB and 16A breaker at the source and in case of any fault, no lives will be hurt.
If there is no such things for outdoor outlet, then EVSE is not the reason to blame.
One can die with OEM granny charger while plugging/unplugging granny charger to the outlet even
though no vehicle is connected. It's just slightly better to have that control box earlier in the loop.
But in terms of real "lives saved" - unmeasurable results. Compared to RCCB before outdoor outlet.

This handle charger must be waterproofed. Then it is good enough.



I'm not going to debate safety with you, it is very clear you don't understand why the standard was developed and why a toaster or laptop is not the same as an EVSE or why your design is unsafe and not just because of the long cord. Your cord design as been around a long time and was sold in the EU and was not successful because it was not safe. Let me know the next time you make toast on your garage floor or in the driveway. FYI, dogs love to chew into EVSE cords, is your GFCI EV compliant and does it cut the mains at the box? Since you live outside the US I suppose there is not much risk to you to take this position on safety. I hope you are more safe routing HV cables.
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arnis
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Re: I designed and built a 'better' granny charger ('11 leaf)

Mon Apr 16, 2018 12:19 pm

You are just saying it's not safe while bringing no examples who can be harmed and how can be harmed
by having HV relay closer to the J1772 end compared to wall outlet end.
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gugusse
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Re: I designed and built a 'better' granny charger ('11 leaf)

Wed Apr 18, 2018 10:47 am

I do see some safety issues with this type of EVSE, but nothing that is forbiden.

I installed a 2 pole relay on my EVSE, because who knows how the plug has been wired (incorrectly?).

In Europe, every public station plug is on a RCB 30mA (at least in france)... And good luck to find a GFCI plug in Europe, I'm not even sure it exists, plus the main breaker connection to the grid has one too (300, 350, 500mA or 1A), so if the ground is correctly connected no problem even if it's missing the 30mA RCD.

Let's be honest, the EVSE brick has something making it look safe so for somebody new it's better or if you want to plug to somebody's house knowing nothing about electricity.

When I plug at some friends houses, I sometimes trip the main breaker, none of them worry. Usually it's more about explaining to their family or friends that it's still normal and safe.

Don't be afraid of the electrical monster, just try to tame it!

I'm an electrician (now :D ) and with the work mux did I would probably say engineer.

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

Wed Apr 18, 2018 1:39 pm

arnis wrote:You are just saying it's not safe while bringing no examples who can be harmed and how can be harmed
by having HV relay closer to the J1772 end compared to wall outlet end.


As the length of unprotected conductor grows, safety is reduced. This seems self-evident.
I noticed you're still working with polymers.

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

Thu Apr 19, 2018 6:56 am

What do you mean "unprotected"? Cable is not bare copper. It is double insulated.
Firstly, each wire is insulated separately. And all wires are in another insulator+mechanical protection jacket.
Usually, EVSE cables are heavily armed (more than any extension cable/vacuum cable etc).

I don't see this DIY EVSE being any more dangerous than vacuum cleaner (except missing waterproofing for electronics).
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Re: I designed and built a 'better' granny charger ('11 leaf)

Thu Apr 19, 2018 10:01 am

arnis wrote:What do you mean "unprotected"? Cable is not bare copper. It is double insulated.
.



This statement shows your utter lack of understanding of why the standard was developed. You need to read the standard completely and entirely, the FULL standard that you need to usually pay to get if you want the EVSE to pass standards, There is never supposed to be a live cable to the handle when the car is unplugged or not charging. That is the main issue with your design. There are many reasons they do this and it has nothing to do with other appliances which typically are not used daily in garages or wet locations or connected to auto chassis. I could write pages on this topic but it's pointless because you have decided the standard is pointless. Does your GFCi meet the EV spec at all levels? Does it work on a GFCI circuit? What about your disconnect delay specification? Mostly moot because it only disconnects at the handle which is the exact opposite of what it is supposed to do. Use your imagination a little and think about why they developed this standard they way it is written. You are one of several people to build these modified units and none of them could ever be sold and are safe, it they were they would be manufactured. A guy in Germany (pretty sure) did this faulty design years ago and sold them, you could have just bought one from him, he struggled to make it work but hit a wall because it never me the spec at many levels.
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arnis
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Re: I designed and built a 'better' granny charger ('11 leaf)

Thu Apr 19, 2018 1:58 pm

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".
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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