Tracking down earth leakage

[Adam_151]

Not sure I follow, plugwash, any chance of a quick diagram?

(I'm just quite a visual person)

 

[JohnD]

I like RCBOs, one on each circuit gives the protection you need without cumulative leakages or losing everything through a single fault.

Does work out a bit a bit expensive, though.

 

[plugwash]

[code:1]
Mains Load
L _____ ______________________________________________L
)|(
)|(
)|(
)|(
N _____)|(______________________________________________N
|
Multimeter on current range
E ____________________________|_________________________E
[/code:1]

 

[Adam_151]

Thanks plugwash, that makes sense, slightly impractical though

 

[baldelectrician]

could there be an outside PIR light taken from the ring main? have had this a couple of times

 

[toasty]

You say you had just replaced an RCD anyway (I think!)

Why not take that apart and use the toroid inside to measure any imbalance?

rather than have the secondary trip the relay, just use a multimeter on a millvolt range to measure the potential difference generated by each applicance. It should be fairly easy to attempt to calibrate it too, by deliberately dumping a known amount of earth leakage and seeing what voltage that relates to..

I appreciate the above is scant with regard to detail, but I reckon you'll be able to work it out, should make for quite a useful test tool in the future too.

Good luck with your training as well BTW.

 

[toasty]

Forgot to add, that should mean that you are actually measuring the inbalance between live and neutral, so it matters not how the earth leakage is occuring.

 

[Spark123]

Just a quick word of warning re using the old RCD torroid, this is a current transformer and if open circuited can result in high voltage being present across the coil.

 

[plugwash]

yes its a current transformer so you should use the meter on a current range.

 

[Steve]

Just found this on Fleabay. It might be of use to you. Click Here

Not meaning to alert the mods or anything . . . . . but is the seller's name a coincidence or what!!?

 

[RF Lighting]

I was quite shocked too.
Just a freak coincedence

 

[securespark]

Yeah, right!!!!