2 radial circuits tripping when anything is plugged into one circuit

[pmc64]

Hi

My brother in-law had a new RCBO consumer unit fitted last year (Can't get in touch with installer)

He noticed. Only if he plugged in (any) appliance to 2 x skts Back to back (Different rooms) then 2 radial circuits would trip. (Not an appliance fault as he tested multiples of sources)
(Also both Skts wired to correct terminals on the backs)

He had, had a skirting board fixed a few months back. But I surmised that may not be the problem, as I'm sure a circuit would trip if any screws/nails created a short.

Not sure why 2 radial circuits would trip? 

Could it be a wiring mix up at the consumer; or a missed skt or even jct box on one circuit with reverse polarity being the culprit?

So that when anything is plugged in. The polarity is reversed and causing this fault

Didn't have skt tester to test the 2 skts for polarity.

Anyhow I was hoping an electrician may have an answer or know of this type of fault. Thanks in advance.

 

[revjames]

my money would be on the 2 neutrals of the radials being mixed up. I take it one radial is on each side of the RCD board? There are 3 neutral bars inside the board. A main one where all the sub parts of the board - eg the 2 RCDs are fed from and then one each for the output side of each RCD fed circuit. Its common for the installer to accidentally put the neutrals into the wrong neutral bar, then when any current using equipment is plugged in the imbalance of currents trips it. Best get installed back to sort his problems out.

 

[Sidney]

When did this fault occur? After the board change, after the skirting boards were fixed or more recently?

 

[Sharpend]

my money would be on the 2 neutrals of the radials being mixed up. I take it one radial is on each side of the RCD board? There are 3 neutral bars inside the board. A main one where all the sub parts of the board - eg the 2 RCDs are fed from and then one each for the output side of each RCD fed circuit. Its common for the installer to accidentally put the neutrals into the wrong neutral bar, then when any current using equipment is plugged in the imbalance of currents trips it. Best get installed back to sort his problems out.

Rev it’s an RCBO board? 

 

[pmc64]

Hi Sidney

The problem is that the board was changed last year, and a new skirt was fitted a few months back. (No tripped circuits since works)
So I was theorising...New skirt, no tripping, unless it was intermittent with say a door/floorboard knocking on the skirt for instance (Knocking nail that little bit further in etc)

Most importantly. He ever noticed this fault until recently, as the skts he plugged into to create this fault were in unused rooms, ergo not noticing til just now.
 

 

[revjames]

Rev it’s an RCBO board? 

ah sorry not paying attention, still if both radials tripping under current draw then its likely that neutrals are mixed.

 

[Sharpend]

ah sorry not paying attention, still if both radials tripping under current draw then its likely that neutrals are mixed.

Concur.

 

[kerching]

As said before....neutrals

 

[pmc64]

Thanks guys for giving your valuable time and knowledge, it is much appreciated.

 

[SPECIAL LOCATION]

If this tripping is happening all of the time.. 

(not intermittent or random)...

Every time you plug something into these sockets..

Then it should be a relatively quick test & investigation process for any competent person with suitable test gear.

Are these sockets the only accessories on each of these circuits?

Or do the circuits supply other outlets as well?

:coffee  

 

[Sidney]

It's very difficult to diagnose from afar, you will need to engage a local electrician to carry out some basic testing.

But, if you fully isolate the circuits and carry out the safe isolation process there's nothing to stop you from visually checking for loose cable at the sockets etc. Only do this if you feel you're 100% certain you can do this safely.

Safe isolation