Made me jump!

[Mjward]

Moved into a new house and before I make a start on the serious renovation, thought I'd mount a TV so I have some evening entertainment.

Easy, the previous owners already had one up, just need to move along slightly for new pilot holes for the new bracket. Or so I thought.

Drilled first pilot hole, no issue.
Drilled second pilot hole and lights in room went out. (I didn't connect the two immediately as the microwave was on and this earlier triggered the RCBO).
Drilled third pilot hole and poof, bit of a spark, RCBO triggered again and told me something was not right.

The things that are alarming me are:

1) I've drilled a couple of inches horizontally from where previous mount was installed. Closer to a power socket but nowhere near above. Further away from a light switch and in no logical route of a cable run

2) the room lights are switching off when there was a power overload earlier on the sockets. Don't know why these would be on same RCBO.

This house is completely new to me less than a week ago so don't have a full understanding of the electrics but there s growing number of warning signs that something isn't right

 

[DPG]

Yeah it's bad cable routing that.

As you say, not sure why there are so many cables on that particular route.

 

[Mjward]

Yeah it's bad cable routing that.

As you say, not sure why there are so many cables on that particular route.

Extension completed in 2010, wouldn't regs then have required a protective conduit in this scenario? Either way, no space for a MF wagobox so I'm going to have to crimp/solder and insulate then plaster over

 

[DPG]

Extension completed in 2010, wouldn't regs then have required a protective conduit in this scenario? Either way, no space for a MF wagobox so I'm going to have to crimp/solder and insulate then plaster over

Regs would have required following prescribed zones.

 

[Mjward]

Have excavated around sockets to see what's what and we'll, fair to say that vertical/horizontal routes took second fiddle to the magic of diagonal ???

 

[DPG]

Have excavated around sockets to see what's what and we'll, fair to say that vertical/horizontal routes took second fiddle to the magic of diagonal ???View attachment 86702

To be fair, the slight diagonal of those cables is not really an issue, as they are still within the prescribed zones above the accessories.

 

[Mjward]

To be fair, the slight diagonal of those cables is not really an issue, as they are still within the prescribed zones above the accessories.

True. I just look at it and it screams "they won't know, how will they know". Maybe it's the OCD in me but a professional job this is not.

 

[nicebutdim]

Certainly didn't expect this turn of events.

 

[timhoward]

If the rest of the house is like this, then maybe invest in a multi-tool!

https://www.aldi.co.uk/20v-cordless-multifunctional-tool/p/805384488057701

 

[Mjward]

If the rest of the house is like this, then maybe invest in a multi-tool!

https://www.aldi.co.uk/20v-cordless-multifunctional-tool/p/805384488057701

Already in the tool bag, first thing I pack!

 

[Mjward]

Will start tracing back each socket to the relevant RCD using my loopcheck and RCD check function (ie trips it). Out of curiosity, tried it on the TV socket and only the RCCB on the end tripped, not the single circuit RCDs (including the one labelled for the relevant socket). That's not normal is it?

 

[timhoward]

Out of curiosity, tried it on the TV socket and only the RCCB on the end tripped, not the single circuit RCDs (including the one labelled for the relevant socket). That's not normal is it?

That is normal. On your setup the 2 RCCB's are detecting "electricity going the wrong way". The other breakers in the middle are detecting "too much electricity flowing (overcurrent protection)". Your gadget is testing the RCCB, not the overcurrent protection.
(You also have an RCBO for smoke alarms that does both functions but that is the exception on your consumer unit)

 

[Mjward]

That is normal. On your setup the 2 RCCB's are detecting "electricity going the wrong way". The other breakers in the middle are detecting "too much electricity flowing (overcurrent protection)". Your gadget is testing the RCCB, not the overcurrent protection.
(You also have an RCBO for smoke alarms that does both functions but that is the exception on your consumer unit)

Ah ok, good info thank you. Is there a DIY friendly gadget that can trigger overcurrent protection?

 

[Dartlec]

Ah ok, good info thank you. Is there a DIY friendly gadget that can trigger overcurrent protection?

There isn't even a professional friendly gadget to test them - If there wasn't an RCD in your case then the screw through them might have tested if if you'd nicked Live to Earth - For various reasons that's not a recommended test method though!

MCBs are generally considered to work (and mostly do as they are old well tested technology) - and the only testing ever needed on them is to ensure that they isolate the circuit when switched off.

 

[littlespark]

Ah ok, good info thank you. Is there a DIY friendly gadget that can trigger overcurrent protection?

Not really. You just have to trust that say a 32A trips at approx 32, and not way over 40.

without taking the cover off the board, I would assume that the rcbo for the smokes is directly off the mainswitch, not through either rcd.
The left hand rcd looks to me to control the 6 MCBs on the left, and the right hand rcd does the other 6.

It’s not clearly labelled as such, and maybe should be.

There should also be blanks inserted in spare mcb positions to stop anything being inserted.

 

[Mjward]

Thank you both. I was approaching it from the angle of properly mapping each socket to its respective MCB. For example I know in one upstairs bedroom, 2 sockets are on one circuit and 1 socket is on another so was thinking it would be useful to create a file that documents what each relates to but maybe that's just me being unnecessarily ----! ?? Just thinking down the line it would be useful to know that I can turn off just one MCB to work on a particular circuit rather than the whole board but I guess it doesn't really matter