can i use henley blocks in ceiling?

[thekingiam]

i have 25 mm swa suplying cu in top flat, i want to put in 80amp type s 30ma rcd to protect cable and time delay.
problem i have is cable route is onto existing ceiling which will be lowered and pipe work in way to rcd so i was thinking of connecting to henley blocks in ceiling then down to rcd is this allowed?
while typing this out i thought i don't need henley blocks as i could put a back box in ceiling connected to armour and just peel back armour so no need to terminate if that makes sense?

 

[kingeri]

Surely any joint in ceiling would need to be MF?

 

[telectrix]

Maintenance free joint if not accessible.

 

[Piratepete]

Hi
I think you have 2 problems here.
1. A hidden connection box with screw terminals.
2. Availability of 30mA S type rcd. 100mA is no problem!

Pete

 

[Paul.M]

Crimp and heat shrink is only thing I can think of.

 

[Octopus]

Longer tails and the RCD??

 

[Paul.M]

Separate the whiskers so they can fit into a few wago blocks!!! Joking

 

[thekingiam]

my last point was as you would connect armour of cable to a metal box before entering a cu , i can do this in ceiling void as i am not cutting into lives and seperate earth ie 3 core.
i would imagine i need a connection to earth from metal box to protect armour?
maintanance free ?would it have to be as only a swa armour connection?
have 80 amp 30 ma s type rcd going to feed a lower rated rcd so lower rated rcd trips first

 

[Piratepete]

my last point was as you would connect armour of cable to a metal box before entering a cu , i can do this in ceiling void as i am not cutting into lives and seperate earth ie 3 core.
i would imagine i need a connection to earth from metal box to protect armour?
maintanance free ?would it have to be as only a swa armour connection?
have 80 amp 30 ma s type rcd going to feed a lower rated rcd so lower rated rcd trips first

I don't fully understand what your thinking is. If cables are connected together in the ceiling void with no marked access the connection has to be Maintenance Free and this includes earth conductors. If you are an electrician you'll Know what this means - no screw connections - only crimp, solder and clamp units designated MF are ok.

RCD. a. Why do you need one? b. You cannot follow a 30mA S Type with a 30mA, apart from which I don't think you can buy one anyway.

Pete

 

[thekingiam]

main incommer from meter goes to isolator then into henley block on distrubution board then split from henley to cu's on the board,the new supply to top flat will come from this henley to rcd on board then swa tails into ceiling metal box then on to top flat cu.
does this make better sense ?

 

[thekingiam]

sorry 80 amp 100 ma!

 

[thekingiam]

the rcd protects the length of swa against drilling etc, also time delayed so top flat rcd trips before the time delayed one, the metal box in ceiling will have a blank plate flush with ceiling so access is no problem for inspection.

 

[Paul.M]

As well as all this you could make a service hatch in the new ceiling and put it down on the cert.

 

[thekingiam]

would a service hatch be over the top? face plate would do surely.

 

[Paul.M]

would a service hatch be over the top? face plate would do surely.

TKIA yes, only you have seen the job, its your call mate. It just depends on how much working space the next man needs if he/she needs to work on it or test it?

 

[shagbite]

rcd for swa not strictly needed, but it won't harm.

 

[thekingiam]

it's my own house so not realy needed but as i would of put an isolator in anyway 20 quid for rcd doesn't seem to much effort.
edit missus house she would kill me if she heard me calling it mine!

 

[Paul.M]

it's my own house..................
edit missus house she would kill me if she heard me calling it mine!

Are our wife's related? I know what you mean mate lol

 

[HandySparks]

main incommer from meter goes to isolator then into henley block on distrubution board then split from henley to cu's on the board,the new supply to top flat will come from this henley to rcd on board then swa tails into ceiling metal box then on to top flat cu.
does this make better sense ?

What's the overcurrent protection for the new SWA submain?

 

[Fin170]

20 quid for rcd doesn't seem to much effort.

Time delayed is several times more than £20, buying proper SWA glands and making use of that 'earthed mechanical protection' would be a better idea imo