Still unsure about testing for borrowed neutrals.

[Guest111]

You know TC technically I suppose he is right,just shows how we get used to calling something a different name,probably because thats what we were told it was called in our training,years ago,I still call pipe half inch and three quarter inch because thats what it was when my dad did plumbing,even though I,ve gone metric on everything else lol.

 

[telectrix]

whenever i see, or get told, a metric measurement, out comes the tape measure to convert to english. then i can see how long, big, wide something is. just totally unable to visualise something in mm ( except drill sizes). cms? forget it. and if you tell me it's 16deg.C outside, i still won't know whether to put a coat on.

 

[Top Cat]

Remember when doing a CU change you may not catch or find it until you energise the circuits and the RCD trips as I said earlier it is not that common up here in fact I was asked by a mate who was running a small business he is 63 and he could not figure it out so he gave me a call I turned up and clocked it sraight away . That was the first time he had seen this hence his confusion

Strange really, it used to be such a common practice in my neck of the woods. But i am from Gloucester and the local saying is "strong in the arm, thick in the head!"

 

[nickblake]

Common practice up here too , did a cdu change the other week basic tests didnt pick it up but knowing the houses on the estate i was suspiciouse and confirmed when the RCD's tripped and if both trip you know is borrowed neutral luckily it was easy to recify so good job

 

[growler]

what other faults are common when pre testing before a cu change? would a screwed neutral onto a back box be one?

 

[telectrix]

could be. also a N/E reversal in a socket, without an RCD most appliances will run happily on L-E.

 

[DurhamSparky]

^^^ above

 

[Jay Sparks]

could be. also a N/E reversal in a socket, without an RCD most appliances will run happily on L-E.

Had this problem a few months ago when I changed a cu for an all rcbo one. Soon as I put down stairs light on the rcbo tripped. Turned out to be the wall lights. Took one off and noticed the E/N were in the wrong terminals and had been for a few years and the lights still worked, so I changed them and thought, that ill do, ill turn that rcbo on and Im done........NOT, the rcbo tripped again when switching the lights on....then it hit, it was stareing me in the face, a nice big oil painting hanging about 4 inch below the light, nail from for the hook straight through the N. Again this had been like this for ages but obviousley, the N was the earth until I changed it round.
Couldnt believe I didnt notice that big --- picture.lol


Jay

 

[tuckermot]

A good tip for checking for a borrowed neutral on the lighting circuit in a domestic dwelling is to open up the down stairs light switch ( normaly 2 gang ) and see if there is a link wire going from the comon of one gang linking to the 2nd gang and then a red live coming from the L2 going up to the landing switch and then of to the light fitting and then the neutral to the landing light coming from up stairs lighting

 

[Guest111]

A good tip for checking for a borrowed neutral on the lighting circuit in a domestic dwelling is to open up the down stairs light switch ( normaly 2 gang ) and see if there is a link wire going from the comon of one gang linking to the 2nd gang and then a red live coming from the L2 going up to the landing switch and then of to the light fitting and then the neutral to the landing light coming from up stairs lighting

Basically what I said above but I think you explained it a bit simpler.

 

[cogsey133]

In 36 years in Scotland I have never come across a shared neutral or have I lived a sheltered life ?

Sheltered life i'm afraid mate because come across plenty here in Fife usually in MOD establishments.

 

[i=p/u]

well i would say test between neutral bars. and i would agree on putting them on the one mcb= saving an mcb and maybe saving a life if you can actualy die from 230v

 

[Adam]

Interesting topic this any one got drawn examples of a "borrowed N " as I to can get a mental fog over this at times
Pict

See: File:Old2way.png - Wikipedia, the free encyclopedia

Light on left would be downstairs, and light on right would be upstairs.