Fault

[Thewiz]

Hello just had quick look at the fault on the way home last night as I was passing by. Basically the up sockets are on a rcbo it's a bit strange because when ever you plug some thing in like a battery charger for a drill or a power tool it does not trip. But when plugging in a heater it trip straight away. Didn't have my megger with me so didn't carry out any test as of yet, any one seen that before.

I swapped the rcbo over with a new one and still happened. I will run a ramp test to see it trips when I return along with the basic ir and r1+r2 tests.

I have seen it before when polarity has been reversed in a socket when energising a load the Rcd will trip.

 

[trev]

So you went to a job which you knew might need some testing without the one piece of equipment which would have allowed you to do it?
Interesting mate.
I appreciate that you were heading home and so time may have been short but surely loosening the socket face off for a quick look would have been the clever thing to do? However, the fact that only one item of kit is causing problems would point me in a certain direction.

 

[Thewiz]

Yes it was late. I explained I didn't have a tester with me she said ok can you just pop over and take a look.

Anyway.... What direction would that be?

 

[trev]

Well if only one thing is causing the RCD to trip then surely that's where to start looking?

 

[Thewiz]

No. I may not be explaining it correctly.

When a load such as a heater is plugged in the Rcd trip. A radio for example does not trip the Rcd.

If I took the heater to another socket it still triped.

 

[trev]

"The heater"?
Isn't that telling you something?
Is this heater the only thing that is tripping the RCD?

 

[Thewiz]

No because, another heater does the same thing and so does the underfloor heating

 

[trev]

But nothing else does it?

 

[Thewiz]

Nope just those as far as I could tell. One of the hostel only trips wen it's on level 2 heat.

 

[trev]

So several things are tripping the RCD and they all have one thing in common. They all have heating elements.
So if things without heating elements are not tripping it why are you wasting time thinking about polarity issues in the back of sockets?
Pat the heaters, test the UFH. That's where my money would be going if I was a gambling man.

 

[Thewiz]

All heater work on ground floor ring?

 

[Pete999]

It's an RCBO isn't it? if the underfloor heating is on does and the heaters are not plugged in does the rcbo still trip? is it only when you have the U/F heating and the heater in use the rcbo trips?

 

[TPES]

Drop all neutrals out the neutral bar.. Connect up only the circuit that the heater is being plugged into. RCD up. Everything else off.. I'll bet heater stays on. This isn't a fault with the heater

 

[TPES]

There's an inbalance causing the RCD/RCBO to trip.

 

[HappyHippyDad]

I have only skimmed through this thread as I am eating a sandwich and I am enjoying it, however..

Low powered loads dont trip the RCBO!!
High powered loads do trip the RCBO!!

Perhaps it's nothing to do with earth current?

What is the ampage of the RCBO? Clamp at CU see what it is drawing.