EV Charging Station NS (single-phase): is a Type A RCD enough, or is Type B required?

Q&A and troubleshooting EVCS
1

Hello,

I have installed a Victron EV Charging Station NS (EVC200300200, firmware v2.09) on a single-phase 230 V supply, upstream of a MultiPlus-II GX 48/6500 (on its AC-in side). It is currently protected by a C32 breaker and a 30 mA Type AC RCD, which I know is not suitable.

The manual recommends a Type B RCD, but I could not find whether the charger has built-in 6 mA DC leakage detection (RDC-DD per IEC 62955).

My questions:

  1. Does the EVCS NS include 6 mA DC fault detection? If so, is a 30 mA Type A (or Type F) RCD upstream enough?
  2. If not, is a full Type B mandatory, or is a “Type B-EV” (Type A + 6 mA DC detection) acceptable?
  3. Would a generic Type B RCD (e.g. Tongou TORD4B-63, 2P 63 A 30 mA) be fine, or do you recommend a specific certified product?

Thanks in advance.

2

If the manual specifies a Type B, then, in terms of intended use, you don’t really have a choice.

I would only ever use products that carry the certification marks required for the local market.

Since an external Type B RCD is required, I assume there is no internal DC residual current detection.

3

No, unfortunately not.

Now it gets complicated: a Type B RCD generally doesn’t trip on DC residual currents of around ±6 mA. As a result, your upstream Type A RCD may be “blinded” and its ability to trip impaired. If there’s no Type A RCD upstream of the Type B, you can use a Type B. If there is a Type A RCD upstream of the RCD for the wallbox, you should definitely use a Type EV with 6 mA tripping. You can also use the Type EV without an upstream Type A RCD.

4

I’m also looking into what components I need to charge a BEV. I initially did a double take at the price of a Type B RCD, because I hadn’t expected such a big difference compared with a Type A. But the Victron EVCS datasheet clearly states that a Type B is required. Another point: I’d only go for a reputable brand. This Tongou sounds very Asian to me, and despite the bargain price, I wouldn’t use it in safety-critical applications. Even if an ABB or Hager costs twice as much (or more). It’s like smoke alarms: they’re just installed and never do anything. You could wonder why you spend money on them at all. But when push comes to shove, they MUST work.

5

The new EVCS, which is due to become available in a few weeks, will have an integrated RCD, so there’ll be no need to provide one externally.

6

Unfortunately, there’s still no datasheet for the new EVCS. Does the new EVCS really include a full RCD, or just 6 mA DC protection?

The 6 mA DC protection would still mean that an RCD Type A is needed in the distribution board, which would be perfectly fine in my opinion — perhaps even the better solution. A Type A doesn’t cost the earth.