EVC's & RCD's - a question for Mr Kenyon

Tolly said:

Therefore, what is your intention

First of all, it is not "my" intention. The requirement comes from international standards, IEC 60364-7-722, and is endorsed by our national Committee, JPEL/64, for inclusion into Section 722 of BS 7671.

Second, Regulation 722.531.3.101 of BS 7671 has changed slightly in Amendment 2:2022, to help clarify the situation.

722.531.3.101 Unless supplied by a circuit using the protective measure of electrical separation, each charging point incorporating a socket-outlet or vehicle connector complying with the BS EN 62196 series shall be protected individually by an RCD of Type A, Type F or Type B and having a rated residual operating current not exceeding 30 mA.

To fully understand this requirement, we first need to understand what is meant my the term "charging point", for which we look in Part 2 (bottom of Page 3 of BS 7671:2018+Amendment 2:2022):

Electric vehicle charging point. The point where the electric vehicle is connected to the fixed installation.
NOTE: The charging point is a socket-outlet where the charging cable belongs to the vehicle, or a connector, where the charging cable is a fixed part of the electric vehicle supply equipment.

So, if there is only one "outlet" in the EVSE (the "charging equipment"), the RCD in Regulation 722.531.3.101 could be:

(a) In the EVSE itself

(b) In the distribution board or consumer unit, but dedicated to the circuit supplying the charging point.

BUT NOT (i.e. not ever) an RCD in a split-load board, as that supplies other circuits, or potentially outlets, whether electric vehicle or otherwise.

HOWEVER, if the EVSE had two vehicle outlets (as some I have come across), each outlet must be protected individually by an RCD, and therefore the RCDs would be part of the EVSE.


And the question as to why this is a requirement and why RCDs in split-load boards ought not to be used upstream of EVSE ... well, the EV and the EVSE may both have some "leakage current" and the total of both may be at or around the "limit" discussed in Regulation 531.3.2 (10 mA).

One of 10 22Kw twin units we installed from Garo. RCDs individually protect each socket. 300mA type A S-type RCD as main incomes in the DB supplying this pillar. 
As far as I can see on the domestic side, the EVSE circuit is normally bunged in with other circuits in a split load board so RCD is not individual to the EVSE.

Hi Tolly if you @ tag someone then they'll get a notification in their message centre that they've been tagged in a discussion.  Works in the same way as it does across other social media platforms such as LinkedIn, Facebook, Instagram, Twitter etc.  Just type the @ symbol and then start typing their username. You'll see a list of potential matches for you to choose from. If the person's name isn't there then check it's spelt correctly or is the right username, if it still doesn't appear it means that user has opted to not be tagged in discussions. 

So rather than adding Graham's name in the subject line of the topic and hoping he will spot it, you can @ mention him in the message itself i.e. 'Can you help me gkenyon 

Sorry for the notifications you'll now be getting gkenyon 

Hope that helps!

Lisa

Lisa Miles I can confirm, I received a notification because of the tagging, which brought me back to this thread.

Thanks Graham 

lyledunn said:

As far as I can see on the domestic side, the EVSE circuit is normally bunged in with other circuits in a split load board so RCD is not individual to the EVSE.

 lyledunn  whilst this may have been happening, I think I know why, but it didn't make it right. Let me explain. Back in 2018, the requirement began as follows:

722.531.2.101 Except for circuits using the protective measure of electrical separation, each charging point shall be protected by its own RCD of at least Type A, having a rated residual operating current not exceeding 30 mA.

So, this said the outlet ('charging point') ought to have its own RCD although there would be nothing to stop that being fed by another, presumably one in a split load board??? (I will come back to this very shortly ... please keep reading.)

Those who are diligent in reading BS 7671 and its amendments will be aware that in 2020 the requirement changed again in Amendment 1, and there was no mention of the charging point (outlet) having its own RCD:

722.531.3.101 Unless supplied by a circuit using the protective measure of electrical separation, each chargingpoint incorporating a socket-outlet or vehicle connector complying with the BS EN 62196 series shall be protected by an RCD having a rated residual operating current not exceeding 30 mA.

Is this an omission? Well, not if you consider that the general rules, Regulation 531.3.2, ought to have indicated unwanted tripping of a split-load board arrangement, or a single 30 mA RCD supplying two outlets ('charging points').

However, it's clear the messages are getting mixed, and in 2022 we are back with a statement in 722.531.3.101 in my earlier reply, with the word 'individually' to at least try and indicate an issue.

Thank you for your detailed replies, and sorry about the 'your intention', I was simply thinking about you as the lead author.

Regards

T.

Thank you for the info.

T.