Uk installation – tripping RCD

[MarkyMark7890]

I’m trying to install my new Emporia Gen 2 vue into a standard domestic consumer unit, yet when switching the breaker on, the RCD for the breakers trips.
I’ve contacted Emporia and they suggested the I should connect the red and blue to the neutral bar that the black power wire is associated with and the white neutral wire should be in the neutral bar that the RCD is connected to.
So:
Black to 16A breaker
Red & Blue to neutral bar
White to neutral bar connected to RCD neutral.

I’ve done this and the RCD still trips.
Removing the black wire (obviously) stops the RCD from tripping.

What am I doing wrong?

[djwakelee]

I’m far from an expert on UK wiring, but it sounds like your RCD (residual current device) is the same concept as our GFCI’s (ground fault circuit interruptor) here in the US. Since the Emporia wiring doesn’t leave the electrical box, a connection through a special fault protection device like that is not needed – you’d normally just connect it to a standard circuit breaker. However, if the way your electrical box is setup there is an RCD upstream that protects all the other individual circuits in the box, then I understand why you have to would need to deal with this.

Fundamentally, when connecting up through any fault protection device, you have to have all the current go through the same supply and return wiring that the device monitors. If the protection device sees a mismatch between the supply and return current of a certain amount, it trips. It sounds like you had the white wire go back to the RCD monitored neutral circuit, but the blue and red return elsewhere to an un-monitored neutral bar. Since there is current in those other wires (though small), your fancy RCD is not going to like that and think there is an actual fault.

If you can post a photo it would probably help. But if you are installing Emporia on a new single pole circuit (dedicated circuit breaker), that would go to the black lead and all the other wires (white/blue/red) would go to where you connect your neutral return wires in the box. If you are installing a double pole breaker or fault protected breaker like an RCD (which switches 240V hot and potentially neutral), your hot would go to the black wire and all the other 3 wires go to the neutral output of the protection device.

Hope that makes sense. If it makes it easier, for your 240V application, think of the Emporia black wire as the power feed (hot wire), and all the other wires (white/blue/red) as a single neutral. What’s really going on is the blue and red are the other ‘unused’ hot phases – they are not used in single phase applications and must be tied to neutral (white) so there is no induced voltage on them to confuse the system.

• This reply was modified 2 years, 7 months ago by djwakelee.

[MarkyMark7890]

Hi djwakelee,

See attached.
All three neutral wires are in the same neutral bar as the RCD and the live is out from a breaker that is served by the RCD.

Kind Regards.

 

[natbesh]

OK – i’m based in Australia & seeing as we both speak the Queens English i can help!

You need to make sure the power & neutral are BOTH on that same breaker. What is happening is that the Vue is drawing its power via the positive from that RCD, BUT its flowing back via another RCD. So that RCD assumes its hitting earth & tripping.

https://uploads-ssl.webflow.com/5fff2b7694451e66ba2f5a3d/60ad6596ab10855910ef23d2_Gen%202%20Emporia%20Vue%20Installation%20Guide.pdf
Black is POWER for the Vue unit, connect that to the positive output of the RCD.
White is NEUTRAL for the Vue unit, you MUST connect that to the neutral output of the SAME RCD.  If you put it anywhere else – it’ll trip

Then she’ll be right.

[natbesh]

I hope thats clear?
Your RCD’s are probably like ours in Aus… the RCD has Live & Neutral IN at the top – then Live & Neutral OUT at the bottom, you need to make sure you connect the black & white to the OUT on that single RCD.
The others should sit on the neutral out also.

[MarkyMark7890]

I moved everything onto the same rcd circuit (live and neutrals) and the RCD continued to trip.

So I move the lot onto a second rcd circuit and it doesn’t trip and the emporia boots up fine – weird.

Time to investigate why the first trips and the second doesn’t.

[natbesh]

Do some searching on how RCD’s work – basically its about balance.

The current in/out of the live/positive lead must be identical to the current out/in of the neutral/negative line.  If they’re not balanced the RCD will trip.

Black & white must be on the same RCD, the others may need to be elsewhere (depending on the current – they may/may not trip, they may also make that circuit trip early).

Do you have a photo of the setup? wires in/out of the RCDs?

[m0v1em4n]

Hi Guys,

Just got my Vue 2 and having the same problem , at the moment I only have the black and white leads connected and i doesn’t trip, but got an error in the app about phase,  but will try your suggestions.

[fclauson]

thanks – here in Ireland (same as UK) 240V single phase to the house

RCD was tripping on first install

as suggested – there are two neutral buses – one direct from grid – a second downstream of RCD (or whatever they

are called nowerdays)
connecting the black lead down stram of RCD and the others on the grid tripped the RCD (i.e. working as it should)

so thanks for the fix above – all working now

[Author]

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