Can an upstream fault cause an RCBO to trip?

[LlandrilloSpark]

Fellas

Scenario - 1 main three phase board feeding 3 further three phase boards with each of those feeding 15 single phase boards containing only two final circuits each.

The fault is on the final circuits, ive tested the final circuits and all clear, can a fault on the distribution circuits upstream cause the RCBO to operate?

cheers

 

[telectrix]

i suppose a poor connection upstream of a RCD could cause an imbalance

 

[Marvo]

I've heard of sodium/mercury lighting switchgear like streetlighting causing RCD's to trip. Not sure if it's a harmonics issue or if some residual current devices are more prone than others.

 

[pushrod]

It is my understanding that certain circumstances upstream of an rcd/rcbo can cause tripping eg voltage spikes, switching of large inductive loads. Are you confident that the rcbo is working correctly - what does a ramp test show and are you certain that nothing being used on the circuit in question is not allowing an earth leakage

Edit also heard the other day of walkie talkies causing rcds to trip.

 

[GLENNSPARK]

It is my understanding that certain circumstances upstream of an rcd/rcbo can cause tripping eg voltage spikes, switching of large inductive loads. Are you confident that the rcbo is working correctly - what does a ramp test show and are you certain that nothing being used on the circuit in question is not allowing an earth leakage

Edit also heard the other day of walkie talkies causing rcds to trip.

Walkie talkies...."BREAKER...BREAKER"....lol........

 

[LlandrilloSpark]

nothing leaking to earth as the final circuits power 3 light fittings,2 leds, and 2 sockets only between them!, rcbo trips as 21mA, so i changed to a c type tripping at 27mA but i clamped the earth and under full load there isnt 2mA leakage, im just weighing up if i am going to have to test all the distribution circuits also

 

[i=p/u]

clamp all the earths and see which circuit has highest earth leakage current,, beware of what i say!!!! but beware of my future knowledge

 

[LlandrilloSpark]

none of the final circuits leak anything at all so thats why im asking about the upstream fault, I think for the time it takes i will test the distribution circuits

 

[pushrod]

Is there any electromagnetic/radio interference near the rcbo in question? Is it tripping all the time immediately or at specific times or just occasionally.

 

[i=p/u]

sorry for being dumb there