Discuss tt and rcd problems in the Industrial Electricians' Talk area at ElectriciansForums.net

B

bigal

Ahha I've found where to start a thread.
Hello everyone I'm newly registered and a bit green in finding my way around this site, but i'll do my best.
Here goes with my phenomenon.
Been working on a TT system, Just finished rewire of a house to 17th. Installation required a supply to an out building. Here my problem started.
I wanted to protect the cable going out of the house on a 30ma rcd (it was necessary). I Installed a garage board in the out building that also had a 30ma rcd as a main switch, so to avoid nuisance tripping I disconnected the outgoing cpc (the one from the main board in the house) at the garage board end and added another stake to give it it's own earth supply.
All seemed ok until I tested the rcd at the garage board end. It tests fine on x1 but when I test on x5 it trips the rcd at the house. This should not be possible because the outbuilding supply has not got a direct path back to the house because it is disconnected inside the garage board and relies solely on the nearby stake. earth electrode reading at the house (main earth was 20 ohm (loop test) and reading at outbuilding end 18.5 ohm. Any suggestions?
NICEIC technical say it's not possible. However, I've taken everything apart and checked for cross connections etc and put it all back together again. Still the same happens.
Help please. Bigal.
 

Reply to tt and rcd problems in the Industrial Electricians' Talk area at ElectriciansForums.net

Similar Threads

Hi all, Been a while since I have been on here. I have been on an apprenticeship the last 3 years training in the BMS world. Taking that into...
Replies
7
Views
320
Doing a kitchen job for my daughter’s music teacher, who also happens to have been in my wife’s class at school. Nothing big… just a little...
Replies
2
Views
232
Hi Guys, Long time member and not a regular user here. I do pop in here when the odd unknown pop's up and unable to locate an electrical dilemma...
Replies
4
Views
853
Keeping this brief.....................New dwelling.....TT system with 100mA S type rcd protected supply to local board with 30mA RCD. Freelance...
Replies
21
Views
3K
Hi all, I am at odds on whether RCD protection is required on an SWA of 14 metres, clipped direct under flooring direct from CU to an exterior...
Replies
9
Views
724

OFFICIAL SPONSORS

Electrical Goods - Electrical Tools - Brand Names Electrician Courses Green Electrical Goods PCB Way Electrical Goods - Electrical Tools - Brand Names Pushfit Wire Connectors Electric Underfloor Heating Electrician Courses
These Official Forum Sponsors May Provide Discounts to Regular Forum Members - If you would like to sponsor us then CLICK HERE and post a thread with who you are, and we'll send you some stats etc
This website was designed, optimised and is hosted by Untold Media. Operating under the name Untold Media since 2001.
Back
Top
AdBlock Detected

We get it, advertisements are annoying!

Sure, ad-blocking software does a great job at blocking ads, but it also blocks useful features of our website. For the best site experience please disable your AdBlocker.

I've Disabled AdBlock