new radial cercuit

[matt1111]

I have put a a radial circuit in my ext and i have use 2.5 cable and have 6 double sockets with in a 20 sq area.I have put it on a 20 amp rcd in consurmer box.
I have tested the scokets useing a scokets tester and they are come up all right.when i went to put any power in scoket it blown fuse.

 

[ban-all-sheds]

1) You've just learned that there is more to properly testing a new circuit than using one of those socket testers.

2) Is it really a fuse that blows?

3) When you applied for Building Regulations approval, what did you say would be the way you'd comply with Part P?

 

[Chri5]

Well you've done something wrong otherwise the circuit would energies and work.

Undo all the socket plates and check that each has the LNE correctly wired and that all terminations are firmly in place. You may find that when screwing the plates down and compressing the cables that something has worked loose.

You should have used rubber grommets on the back boxes (if metal), if you haven't check the cable entry to make sure no cabling has been sliced via the metal hole entries on the b/boxes.

Once they have been confirmed as correctly terminated another option would be to try the circuit on a known and working MCB encase yours is faulty.

You could also photo and post the terminations at the CU and sockets so 'we' can review your handy work.

A new circuit should be notified to the LABC or done via a part P reg spark.

Here's the wiki diagram, which may help:-

 

[sparkybird]

what sort of socket tester did you use? The martindale type plug with 3 lights only works on an energised circuit, and you said that as soon as you switched mcb on, it tripped.....

SB

 

[rebuke]

Is it a 20A MCB (in which case is it protected by an RCD), or is it an RCBO - my bet is on a misconnected neutral.

Pics of the inside of the CU identifying which is the new circuit, and which terminals it's wires go into would help us work it out...