marginally baffled

[Leshark]

Hi all, have new power supply & CU (split load), all fine for a month (no changes) while on holiday one RCD tripped, suspected downstairs ring, put on MCBO, again while away tripped? The puzzle to me is that having tested the ring all fine although the R1+R2 are high (below pass) and it never happens when we're home?

 

[kingeri]

What's an MCBO?

 

[ian.settle1]

Sure it is something that someone is not plugging in rather than the circuit?

 

[Octopus]

Hum.... next time you go away unplug as much as you can.

Out of interest is the board a dual RCD?

 

[bigbaddave]

Does this mean its on both RCD and RCBO now?

 

[Ducksy]

Does this mean its on both RCD and RCBO now?

Sounds that way

 

[Octopus]

A photo or 2 would be interesting!

 

[DNS1]

If you've got a new install, surely it's best to call the original sparks back...

 

[Octopus]

If you've got a new install, surely it's best to call the original sparks back...

I think he is the sparks

 

[DNS1]

I think he is the sparks

Oh... I wasn't sure given some of the terminology...

 

[Leshark]

No, when installed it was a 17th ed spit load duel RCD board, now it has RCBO then two RCD's I had an RCBO from another job and put it on to separate the suspected ring, I could unplug everything, or even one at a time to try and isolate the problem (if its an appliance) but so far it has never tripped while I'm in? I was considering running appliances off the other ring one by one until a different circuit trips, but this could take a while, and advances?

 

[Leshark]

Yep, corect, got my Elecsa on my own board only a month ago, for clarity, its a 1960's property, I replaced the board with a RCD spit load board and carried out all the tests to sign it off (several times....) then did the same for my assesment, all passed great, but the downstairs ring had a high (but not too high) R1+R2 reading, appologies if my terminology is not yet upto scratch

 

[Leshark]

No, MK Board, 32a RCBO (Downstairs Ring only) then 63a RCD (Cooker/boiler/DS Lights) 2nd 63a RCD (US Ring/US Lights)

 

[Essex parky]

wait until a day off, have everything as it is. when it trips make a note of the time and try turning it straight back on. is the central heating on the same circuit?

 

[robsparky1975]

Im surprised that the elecsa man did not pick up on the upstairs sockets and lights on same rcd,unless you mistyped,if you have tested the circuit and rcbo then only appliances can be left at fault,is there anything outside off the ring(water ingress?).Have you ramp tested the rcbo,it may sound a bit silly to some but with the weather being as it has and all these parts sitting on cold warehouses for months on end it has been known for rcbos/rcds to work incorrectly.

 

[derek preece]

No, MK Board, 32a RCBO (Downstairs Ring only) then 63a RCD (Cooker/boiler/DS Lights) 2nd 63a RCD (US Ring/US Lights)

So the down stairs ring final has a fault to earth?. Have you done any IR tests. Any appliances that could be causing earth leakage?

 

[Leshark]

wait until a day off, have everything as it is. when it trips make a note of the time and try turning it straight back on. is the central heating on the same circuit?

It was, but when we go away we turn it to low temp so it only comes on if temp drops below 16deg, I was wondering wether the temp drop could affect it, was looking for a 7day 24hr mechanical timer, so I could identify when it trips

 

[Leshark]

So the down stairs ring final has a fault to earth?. Have you done any IR tests. Any appliances that could be causing earth leakage?

IR tested okay, not tested any appliance, I'm starting to feel as though an appliance may be the cause, havn't spent enough time on it, as fair new to this, initially I just assumed it was with somthing I had done, is there a test I can do with appliances plugged in then take them out one by one to try and identify the culpret?

 

[eganelectrical]

Have you tested the rcd for nuisance tripping?? I know you have tried on both rcd and Rcbo but maybe (I always say if it can then it will) they are both faulty!! Try x0.5 with rcd trip time tester and it shouldn't trip.
Other than this is there something damp when the temp drops when your away??
Leave the cold set on the house by leaving temp drop and carry out another I.R test and see if there is anything down to earth?? Maybe rain is getting in and doesn't dry out when your away!

Mmm these ones can be tricky!!

 

[Leshark]

X5 part of standard testing, both RCDs & RCBO tested fine, will ramp test them, IR testing with the heating off was a thought, but not sure I can stand a couple of days without heating