Is there a chance Dual RCD Consumers could be "banned " from rentals soon?

[Mike Johnson]

The dual module/pole Hager RCBO's I have in my UK board sense both line and neutral, unfortunately due to the silly size board installed I have had to resort to single module line only sensing RCBO's for the lighting.

 

[nicebutdim]

The dual module/pole Hager RCBO's I have in my UK board sense both line and neutral, unfortunately due to the silly size board installed I have had to resort to single module line only sensing RCBO's for the lighting.

What I don't understand, and would love someone to explain, is why some countries insist on DP (as opposed to SP+N) RCBOs. If a fault between L&E develops both will trip. If a fault develops between N&E both will detect an L-N imbalance and trip. Faults between L&N could elude both types of device, with overload/overcurrent protection taking over.

There must be a reason for an insistence on true DP protection, but it's not immediately obvious to me.

 

[nicebutdim]

Interestingly I note that Hager's UK page lists all 2 module RCBOs as 1P+N.

RCBOs | Hager UK

Find all Hager products of the range RCBOs

hager.com

 

[pc1966]

There must be a reason for an insistence on true DP protection, but it's not immediately obvious to me.

I think some EU countries used to have two L out of a 3P set, so no neutral as such, or maybe just poor enforcement of polarity (which the UK has had for a long time, well before 13A plugs in the 1940s), so you would need OCPD in both paths.

That also probably predated RCD, so I suspect it has just become an accepted requirement even if not strictly needed if N is strongly enforced.

 

[Mike Johnson]

These Hager RCBO's are listed as two Pole: Electrical Wholesaler - Hager 2 Pole 6kA B-10A 30mA A Class RCBO AD910J -

 

[nicebutdim]

These Hager RCBO's are listed as two Pole: Electrical Wholesaler - Hager 2 Pole 6kA B-10A 30mA A Class RCBO AD910J -

Listed by a wholesaler as 2 pole, but not by Hager.

AD910J | Hager Africa

Looking for AD910J ? Find all the information for Curve B, 6kA type A - 30mA on the official Hager website!

hager.com

I can't help wondering if French and German requirements are for switching of both poles and this issue is one of terminology rather than technology.

 

[Mike Johnson]

It may be something to do with isolation of circuits, but good find in Africa, I take your point, seems they are all only line sensing and the neutral is just dragged along with it.

It's possibly also to do with the multi prong line and neutral bus bars used in most installations and the fact that most CU's do not have a multi terminal neutral bar.

 

[davesparks]

European RCBO's I have used and come across monitor both the live and neutral and are dual module, the regulations in Europe would not allow single module in France or Germany.

Yes because electrical supplies in those countries need protection in both poles.

Many years ago double pole protection was required in the UK when the N-E connection was not necessarily reliable, but now our electricity supplies have the neutral reliably connected to earth and so we only need protection in the line.

 

[Mikegh]

Yes because electrical supplies in those countries need protection in both poles.

Many years ago double pole protection was required in the UK when the N-E connection was not necessarily reliable, but now our electricity supplies have the neutral reliably connected to earth and so we only need protection in the line.

You mean switching the line ?

That's all that's needed

 

[nicebutdim]

You mean switching the line ?

That's all that's needed

That's what I was wondering. Essentially our single module 1P+N RCBO does exactly the same as a 2 module device?