incoperating RCD to existing lighting circuit

[peanut22]

hi all, just got a query which has had me an few work mates in deep discussion! recently doing a bit of work for a bathroom co. there usual spark sometimes installs an rcd in loft space when needed for for ltg and fans e.t.c. he does this by tapping off the existing cicuit with live, neutral an earth through the rcd to new lights an fan, meaning from CU normal mcb protection then rcd protection for bathroom, is this aceptable?

Obviously loft not good for access, but if it was easily accessable, is tapping onto a circuit in this way ok?

 

[Spark123]

Not really, I would have thought the switch should be in a readily accessable location as to limit inconvenience.

 

[Maxxy]

Not sure how the regulations see it, but i wouldnt do it this way. If an old couple, or disabled person are living there, then the loft is not accessible for them, so if the RCD trips they wont be able to reset it..

Also if there's no loft lighting, then likewise it would be dangerous scrabling to find the box in the dark / by torch light.

 

[JohnD]

If you needed to do that (LV equipment in bathroom zones, say) then it would be much better to have the RCD just outside the bathroom, say, above the door, where it is convenient for access, and visble, but not obtrusive.

I might have gone for an RCD FCU which fits a (deep) wall box rather than an RCD in a 2-module enclosure so would be neater.

As a matter of personal preference, I would actually have used an RCBO in the CU, which is where people would tend to look when the lights go out.

 

[Spark123]

Obviously loft not good for access, but if it was easily accessable, is tapping onto a circuit in this way ok?

Only if it is obvious what it is and it everyone knows where it is, still I would prefer to work around doing it this way.