Simple EVSE RCD sensor support?

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Courage2000
Beiträge: 24
Registriert: Do 11. Jun 2020, 22:39

Simple EVSE RCD sensor support?

Beitrag von Courage2000 »

Hello!

In the latest manual, I see some reference for RCD sensor support, but no info on how to connect such a sensor.

+
Firmware updates
2020-06-25 revision 17:
- stricter CP signal check (pilot low decision level, shorted diode)
2020-04-27 revision 16:
- added RCD feedback support for EVSE-WBDIN (e.g. Bender RCMB121 and others)
- added configuration bit for AN pullup (can be disabled)
So, how can we integrate an RDC sensor, so we do not need a Type B RCD?

aiole
Beiträge: 1150
Registriert: Di 12. Mai 2020, 10:54

Re: Simple EVSE RCD sensor support?

Beitrag von aiole »

This is no EVSE-Wifi supported RCD-Sensor!
We tested another RCD, but until now it worked not 100%.

=> So we prefer external Fi-B at the moment.
Compared to internal RCD an ext. Fi-B is rock-solid, his function is separated, it's much cheaper (if you consider development) and most important - you must only change the existing Fi-A, which is quite simple. (You can't use Fi-B after Fi-A)

Courage2000
Beiträge: 24
Registriert: Do 11. Jun 2020, 22:39

Re: Simple EVSE RCD sensor support?

Beitrag von Courage2000 »

Just to be clear
Now I have Rcbo type A -> Rcd Type B -> evse.
If dc fault appear, Type B should trip first.

aiole
Beiträge: 1150
Registriert: Di 12. Mai 2020, 10:54

Re: Simple EVSE RCD sensor support?

Beitrag von aiole »

First I'm not an electrician, but have some information. It's an often asked problem.

Thats not a correct installation. You must substitute Fi-A.
Remember only 1 wallbox per Fi-B is allowed (VDE Germany)

Maybe your install works, but Fi-A wont work if there is DC-failure-current >6mA (Fi-B has 30mA DC&AC). Also Fi-A is not necessary and draws standby-power. Thats why changing is better.

Assumed you have additional components at your Fi-A (not allowed by VDE) than Fi-A-protection wont work for these devices. That's dangerous.

We call it "blinding of Fi-A".
Fi-A can only get max. 6mA DC-failure to work correctly for 30mA AC-protection.
That's why internal RCD should stop DC-failure at 6mA and this could combined with only external Fi-A.

This low 6mA DC-value is a disadvantage of RCD.
I.e. Renault Zoe sometimes exceeds 6mA due special charger and charging stops. With external Fi-B you have 30mA AC/DC and it works.

Courage2000
Beiträge: 24
Registriert: Do 11. Jun 2020, 22:39

Re: Simple EVSE RCD sensor support?

Beitrag von Courage2000 »

Is not logic, as Fi-B already include Fi-A capacity!
The problematic current goes backwards.
From evse -> fi-b -> fi-a (rcbo).

First will trip Fi-B

I have Rcbo (this is rcd type a + normal fuse, all in the same package)

aiole
Beiträge: 1150
Registriert: Di 12. Mai 2020, 10:54

Re: Simple EVSE RCD sensor support?

Beitrag von aiole »

power -> Fi-B -> fuse -> wallbox (EVSE should get separate fuse 6A inside the wb)

Hope you protect the powerlines - not only EVSE-supply.

Jarry
Beiträge: 9
Registriert: Mo 14. Dez 2020, 14:00

Re: Simple EVSE RCD sensor support?

Beitrag von Jarry »

Everything what aiole says is correct.

a Typ B RCD behind a Typ A RCD is NOT allowed! (At least in germany and other areas where similar rules as the VDE is valid)
The problem is, if a small (less than ~20mA) DC error is occuring (eg. with some older Renault Zoes, this is more or less the default), the Typ B will not release but the upstream Typ A will be blinded for ALL AC errors.

just replace the Typ A with the Typ B and all is fine. (connect the Typ B in parallel to the Typ A if you are using the Typ A for other circuits.

-------Typ B-----Wallbox
|
|
|
----Typ A---- other circuits

Courage2000
Beiträge: 24
Registriert: Do 11. Jun 2020, 22:39

Re: Simple EVSE RCD sensor support?

Beitrag von Courage2000 »

Hmm now I have another dilema.

For RCD, is important that you correctly connect the wires IN -> OUT

For the B Type we have:

IN 1-3-5
OUT 2-4-6

But in the pictures we have a Chint nl210 40a B Type

Bild

So, the wiring in the OpenWB is showing that the electric current is entering from the grid in 2-4-6 poles.
From my point of view, the RCD should be reversed by 180 degrees.

aiole
Beiträge: 1150
Registriert: Di 12. Mai 2020, 10:54

Re: Simple EVSE RCD sensor support?

Beitrag von aiole »

!11 openWB-HW ist closed source !!!
Do not show inside pic in public area!

This is same for smartWB.
Respect the copyright!

Courage2000
Beiträge: 24
Registriert: Do 11. Jun 2020, 22:39

Re: Simple EVSE RCD sensor support?

Beitrag von Courage2000 »

Some pictures are from their discussion board :(

https://openwb.de/forum/viewtopic.php?t=547

I can understand the rules and I do not push the issue, but this is paranoia.

A simple search for the issue on Google Images returns the images, with public access.

If I would buy an OpenWB or SmartWB, I have the right to open, test and discuss what's inside, no mather what the producer wants!

I really hate the fact that all the "Open Source" EVSE are in fact a walled garden.

It's open source or it is not?
Smart WB is not Open Source and is using a custom EVSE-WIFi 2, but is really hard to find a technical schematic, even if you buy the EVSE-WIFI 2.

So much for the openness part.

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