submain 10 mtrs away from main supply run in tails

[egginyourface]

Exactly what the title says. The tails have been run under the floor and chased inside a wall with no protection. What should i do?

Its a kitchen rewire and its nearly finished. Theres no switch fuse to isolate sub main only main cut out fuse

 

[Noton1205]

its a time delayed rcd. it is used to provide discrimination with RCD's, as the times 3 rule doesnt always work, according to the more experienced blokes on here.

Never seen an rcd installed before the cu on new installations. That massave site in canterbury has meters which feed 80a switch fuses. Out of those goes 16mm t+e which has runs in excess of 4 meters, but NO rcd fitted until youget to the cu.

 

[johnboy6083]

is it surface, ie on tray, in trunking, clipped ect? if so then that complies, if not then it doesnt

 

[egginyourface]

its chased in the wall and can very easily be damaged...

 

[Noton1205]

No protection john just run clipped to brick then plasterd over

 

[Des 56]

Fit a KMF switch fuse at the meter cabinet end and expose the buried tails
Then either surface trunking, or plate them with a suitable metal strap, otherwise you cant avoid having Rcd protection for the buried cables

 

[JD6400]

I may be wrong but i think you will find that there is no such thing as a s type 30ma , sort of defeats the object !
As for tails over 3m ( depending on your DNO ) you have to install a switched fused disconector and i would not use anything less than swa .
I stand to be corrected but thats how i see it .
Hope this helps

 

[Des 56]

I may be wrong but i think you will find that there is no such thing as a s type 30ma , sort of defeats the object !

CPN RC2100/030T 100 amp 30ma RCD Time Delay S Type | eBay UK

This seller seems think there are

 

[adslev]

I didnt think tails had to be on an rcd? Best thing to do would be what jason said and use swa out of a switch fuse in the meter box. You do need a point of isolation between the meter and the consumer unit if the distance is more that 2M from the cutout.

TT system alone would argue differentif the tasks were more than 3M from cu

 

[adslev]

I didnt think tails had to be on an rcd? Best thing to do would be what jason said and use swa out of a switch fuse in the meter box. You do need a point of isolation between the meter and the consumer unit if the distance is more that 2M from the cutout.

TT system alone would argue different if the tails were more than 3M from cu

 

[JD6400]

CPN RC2100/030T 100 amp 30ma RCD Time Delay S Type | eBay UK

This seller seems think there are

Well i stand corrected !
Still cannot think why anyone want a time delay 30ma ?
Would some one enlighten me please , i honestly can not see the point in one and i do not like to think i am missing something .
Thanks

 

[Des 56]

Well i stand corrected !
Still cannot think why anyone want a time delay 30ma ?
Would some one enlighten me please , i honestly can not see the point in one and i do not like to think i am missing something .
Thanks

If you look at the description at the bottom.It says operating currewnt 100 m/amp

 

[johnboy6083]

sounds like im being the numpty then! i suppose the only reason a hypothetical 30ma s type could be employed, would be to allow 2 RCD's tobe used in series, without affecting discrimination. in a TT setup, you would use a 100ma s type RCD to protect submains, so that a 30mA could be used to protect final circuits

 

[malcolmsanford]

There as to be a rabbit away with this 30mA RCD S type, the only place I can see is this one off sale on Ebay ...........if this is then we have found the holy grail in RCD, as every set of T+E buried tails for all those house conversions done 20-30 yrs ago where you have the T+E run through the house have just had a answer to how to protect them, without ripping the house apart.

I like to see another one of these.