Borrowed Neutral

[tom1]

I've worked round it by ignoring discrimination (I know, but it's easier than chasing out and adding a new neutral) and moving both MCBs onto one side of the board. Simple, but effective!

if u do that then u still have a borrowed neutral?

the dangers still excist?

if u turn off 1 mcb then is it not posible to get a belt?

is it not ok to put both circuits in the same mcb (10 amp) if voltage drop is ok???

 

[avinalarf]

Is this an example of a borrowed neutral...

There's a downstairs light on - when I switch off the breaker labelled "down lights", it doesn't go off. I put the breaker back on and switch off "up lights", it still doesn't go off! It only goes off when I switch off BOTH up and down light breakers.

Could someone kindly confirm if this is the case, and if not, why it's like this?

Cheers

 

[Apache]

is it not ok to put both circuits in the same mcb (10 amp) if voltage drop is ok???

It's either that or mend it! IMO much safer than just moving it over to same side of board and then some other spark comes along and kills themself!

 

[tom1]

It's either that or mend it! IMO much safer than just moving it over to same side of board and then some other spark comes along and kills themself!

i dont want to kill my self with electricity, unless its after a long custody battle with x wife, a toster and a bath,. but wait would the rcd save me, dame foiled by my own demise:_|

 

[Northern Electric]

The best way to describe this method of wiring is to compare it to the way you would wire 2 way switching in conduit, in singles.

Wiring in 3c&e is slightly different to conduit method.

I googled 2 way switching and found this diagram, not the best in the world, but it shows 2 way swithing wiring, conduit style.

http://2wayswitch.com/wp-content/uploads/2008/01/2-way-switch-wiring-diagram.jpg

 

[user 6351]

Tom, thanks for that... a very good point that I didn't cover.

Yes, you do still have a borrowed neutral, but it was a quick and dirty fix to stop the RCD tripping and keep the tenant at the time happy.

I'm the only person likely to do any work on the setup, so I wasn't too worried about leaving it temporarily, and I was sort of relying on the RCD doing its' job if the tenants started playing silly beggars.

I'm actually back there again today to do something else, and having checked out the demand etc, I intend to put both the circuits onto the one breaker.

 

[Andy™]

I've read and re-read some of the posts in this thread and I'm still confused...Don't suppose there's someone out there who could put an example of a "borrowed neutral" in a diagram to help me understand it a bit more.

I think I have that situation with the circuits at my mum's house which became apparent when doing some work. I turned off both up & down circuits to be on the same side.

 

[Robin Spark]

Hopefully this will illustration will work as well. Its took me ages tonight!

Borrowed Neutrals on Lighting circuits in older properties.zip