UK Selectivity : What does it mean specifically, especially in relation to EV chargers

[clanky]

Hi all, been reading around this and i have to admit ive quickly gone out of my depth as regards EV chargers. The charger in question is a Myenergi zappi which has its own internal RCD and PEN protection. So, the usual method it seems, is to fit another small consumer board and install a DP 32/40A (either a RCD/MCB/RCBO) with an SPD. Because of the zappi's internal rcd, it seems that an MCB is the preferred choice of protection for the cable to the charger due to selectivity. What does this mean exactly? and if an MCB is fitted, doesnt that mean the cable is only protected for overload and not for any earth faults? As always, thanks for the input.

 

[Risteard]

The regulations also refer to it being on a dedicated RCD, which some have interpreted to mean that the RCD cannot be shared with other circuits, as it would be in a split load consumer unit.

I personally don't see how else "dedicated RCD" could be interpreted.

 

[PeakSteve]

Actually this is not the case. See this excerpt from the MyEnergi website:

"It is important to note that the standards for EV charge point installation usually require an RCD which meets a specific standard – IEC 61008 for an RCD or IEC 61009 for an RCBO. The RCD in zappi does not fully meet these requirements which means that a separate RCD or RCBO to these specific standards needs to be installed."

I stand corrected.
This has changed in the last year or so - previously Myenergi stated their RCDs were compliant. I double-checked with them on more than one occasion. (I also checked with NICEIC if a "Type-A + 6mA DC" met the requirements - and they said YES!)

 

[PeakSteve]

@PeakSteve if you read the whole thread there is more info about the Zappi and it's internal RDC-DD (not RCD). It's a right royal pain but it is what it is.

Noted.

 

[timhoward]

I stand corrected.
This has changed in the last year or so - previously Myenergi stated their RCDs were compliant. I double-checked with them on more than one occasion. (I also checked with NICEIC if a "Type-A + 6mA DC" met the requirements - and they said YES!)

Lot's of us have been similarly burned. Napit said the same.