Smart mcb?

[JohnW2]

I've been involved with auto reclosers in the rail and energy industry where they are used widely. Typically they hold off for 1-2 seconds and then reclose only once. Useful for things like animals getting fried on rails or wet blown branches causing arcs on hv cables.

That all makes total sense - but, like others, I struggle to see why they would be needed, or even remotely appropriate (or necessarily safe) in a domestic (or, I would think, most commercial) environments.

Said feed circuits always have separate isolation which would be locked and tagged out under a safe system of work. No way would you just isolate the reclosers.

As I've said, that would be my greatest concern about such things in a domestic (or similar) environment.

Kind Regards, John

 

[lightbeing]

You really don't need a second MCB, of any type. You can keep the existing MCB supplying the circuit and use that to feed a WiFi-controlled switch/contactor/relay (such as have been described), and then have the ring circuit (both ends of ring) originating at the output of that switch/contactor/relay. The only small issue is that feed from existing MCB to it would then have to be 4mm² cable (or, I suppose, two 2.5mm² cables in parallel), since it would be carrying all of the ring's load..

Many thanks JW and also very grateful for everyone’s suggestions. Yes, an appropriate contactor controlled by a wifi controlled switch module as you have described would definitely be the best route for this.

Since our cu is now over 20 years old (no rcd protection!) I will get it replaced by a larger 18th edition unit with rcbos and will get a contactor made by the same make.

Since I will have space in the new cu, it would be a lot neater if we could have them all together unless it is absolutely mandatory for the contractor and wifi switch to be installed in a separate box?

I know the cu metal box may prevents or severely degrades the wifi signal, however I would get a wifi switch with a thin trailing arial wire that could possibly come out of the box through a spare cable entry grommet or something like that. Would that approach be permitted?

Many thanks to all

 

[JohnW2]

Many thanks JW and also very grateful for everyone’s suggestions. Yes, an appropriate contactor controlled by a wifi controlled switch module as you have described would definitely be the best route for this.

You're welcome, and I'm glad you agree.

Since our cu is now over 20 years old (no rcd protection!) I will get it replaced by a larger 18th edition unit with rcbos and will get a contactor made by the same make.

Fair enough.

Since I will have space in the new cu, it would be a lot neater if we could have them all together unless it is absolutely mandatory for the contractor and wifi switch to be installed in a separate box?

I can see nothing wrong with that, except ...

I know the cu metal box may prevents or severely degrades the wifi signal, however I would get a wifi switch with a thin trailing arial wire that could possibly come out of the box through a spare cable entry grommet or something like that. Would that approach be permitted?

That's obviously a potential problem which, as you say, could presumably addressed by a WiFi switch which had an 'external' aerial which you dangle outside of the CU in the manner you describe. However, such animals very commonly just have internal aerials, with no facility for connecting an 'external' one - so it might be difficult to found what you want/need. Hopefully I'm wrong - let us know how you get on

Kind Regards, John

 

[oceansoul]

From what I remember with high voltage safe working procedure was to short the outputs so even if a auto system tried the make the system live it would fail, spiking the cables for example.

Almost. HV circuit breakers have an earth position, in which the outgoing circuit is connected to the earthing conductor. Obviously this can only be engaged when the CB is in the opened position.