identifying mixed neutrals

[bartkusal]

Hi everyone wasn’t here for a while, nice to be back.
I got to replace a SP, 16 way fuse board in the office block. It is an old Dorman Smith board.
The question I have is:
Is there is any tricks how quicker to identify neutrals and cpc’s, when you have singles coming into fuse board in one bunch,and everything is messy in board, nothing is labelled, the sequence is not fallowed on the neutral and earth bars, nothing.
I know the hard way, with a bit of common sense, but wonder is there are any tricks you bette rexperienced guys use?
Thanks

 

[7029 dave]

Clamp meter, ie was goes out on L comes in on N. I= both poles

 

[telectrix]

16 circuits? won't take an hour. man up. :frown2:

 

[DuaneMHunt1976]

Power off first

Match up size
Socket or light you find a point and link R1+Rn
Back at consumer unit find the pair
Narrow down the odds

 

[egg67]

Lick finger Touch bang, that's that one. Lick finger touch bang that's the next one, lick finger touch bang that's the next one, see it's easy you just test and all will become clear have fun and let us know if it works

 

[bartkusal]

That's what I meant a hard way and common sense, but the easier way would be clamp meter as Dave mentioned, thanks everybody....

Power off first

Match up size
Socket or light you find a point and link R1+Rn
Back at consumer unit find the pair
Narrow down the odds

 

[bartkusal]

Most probably you right, I always moan before start, but normally it all goes well after start...

16 circuits? won't take an hour. man up. :frown2:

 

[bossian]

Use one of them fuse finder gadgets and rewire the endpoint to suite the poles....

 

[snowhead]

In no particular order,

Pick out the different sized cables.
Clamp for current and match pairs
When you're down to the last few and can't match them, Power off board, remove a single unidentified neutral, power up, see what's gone off. Do the same with fuses to find its mate. (there's a quicker but but not approved.)

 

[amlu]

13A plug with linked l-n-e, plug it in (make sure installation is dead!), get a continuity tester, one probe on one of the lives, then keep probing available neutrals till it beeps and you have a right one. mark up the pair and repeat.
can get some of the light-mate adaptors for light fittings too.

 

[snowhead]

13A plug with linked l-n-e, plug it in (make sure installation is dead!),

It will be,, even if it wasn't..

 

[marc8]

there is a slightly quicker way to find it on a small board like this but might not be the best way (i already know its not before everyone starts on me)

turn on all light switches or any other load
turn OFF each circuit breaker
disconnect 1 Neutral only
use a grey leaver wago insert your led test probe in & lock it down now insert neutral (or a terminal block) lock it down
turn on & off each circuit breaker one at a time whilst putting your other test lead on the neutral bar.
eventually probably last one you will get 230v appear label each one & away you go should take all of about 10 mintues.
don't forget to put N back in each time AFTER YOU HAVE TURNED OFF BREAKER
also at same time if you repeat process for all breakers on each N you will see if anyone has borrowed a N from another circuit thus avoiding later on finding it.

if anyone has ever lost a N before they will know that it will go 230V when you manage to find it back to the Neutral bar.
good luck hope i don't get to much grief for pointing this way out.

 

[sparkdog]

That could be very useful marc8.

 

[davesparks]

That could be very useful marc8.

Useful? It'll be useful for getting you sacked if any employer with half a brain catches you putting people and property in danger like that.

A disconnected neutral is one of the most dangerous faults you can get which is why the installation of a single pole switch or fuse in the neutral is strictly prohibited.

 

[Eddiesparks]

He's not leaving the neutral disconnected