Strange RCD tripping problem

[Toneyz]

You are correct, but I think @Pete999 is on the case.

I would have thought that this would have been ruled out by now.

 

[Mjbarnard]

Thanks for suggestions. Am in the hospital today so haven't been able to do much more observations.

Murdoch (msg 42) not sure what you mean by "off", but all the internal units have been off for months, and tripping occurs frequently when they are not on.

Devon Chris (43) A/C circuits new and completely separate to everything else. HEating is via conventional boiler, underfloor heating radiators, thermostats, controllers etc. Only control for A/C are the buttons on the units and the remotes.

DPG (44) happy to install rcbo's if that's a solution. In fact discussed with previous electrician possibility of swapping whole CU to rcbo's.

Peter999 (45) as I recall original install only provided statement saying it had been checked and commissioned satisfactorily. Don't recall any technical data. I will recheck. When A/C engineers returned to investigate they left a document stating fault lay with dishwasher circuit.

Elsparko (46) I have been pointing this out to A/C company all along, but they don't appear interested.

Wilko (48) interesting point. There are local external isolation switches like your picture. Now I haven't tested recently but on one of the first occasions red tripped , I was away and my wife rang to say she couldn't reset the tripped rcd. I advised her to isolate using the external switch, and she confirmed she could then reset the rcd. I told the A/C company this in no uncertain terms and even provided their engineer with a written summary including this, but they didn't seem to think it mattered.

Lurch (49) obviously will get professional advice but happy to change some/any/all mcbs to rcbos if that provides a solution.

Murdoch (50) I don't know what a clamp meter is, but I would expect an electrician to have or obtain whatever is necessary?

Thanks again.

 

[Pete999]

Thanks for suggestions. Am in the hospital today so haven't been able to do much more observations.

Murdoch (msg 42) not sure what you mean by "off", but all the internal units have been off for months, and tripping occurs frequently when they are not on.

Devon Chris (43) A/C circuits new and completely separate to everything else. HEating is via conventional boiler, underfloor heating radiators, thermostats, controllers etc. Only control for A/C are the buttons on the units and the remotes.

DPG (44) happy to install rcbo's if that's a solution. In fact discussed with previous electrician possibility of swapping whole CU to rcbo's.

Peter999 (45) as I recall original install only provided statement saying it had been checked and commissioned satisfactorily. Don't recall any technical data. I will recheck. When A/C engineers returned to investigate they left a document stating fault lay with dishwasher circuit.

Elsparko (46) I have been pointing this out to A/C company all along, but they don't appear interested.

Wilko (48) interesting point. There are local external isolation switches like your picture. Now I haven't tested recently but on one of the first occasions red tripped , I was away and my wife rang to say she couldn't reset the tripped rcd. I advised her to isolate using the external switch, and she confirmed she could then reset the rcd. I told the A/C company this in no uncertain terms and even provided their engineer with a written summary including this, but they didn't seem to think it mattered.

Lurch (49) obviously will get professional advice but happy to change some/any/all mcbs to rcbos if that provides a solution.

Murdoch (50) I don't know what a clamp meter is, but I would expect an electrician to have or obtain whatever is necessary?

Thanks again.

So in layman's terms "a whitewash"

 

[Octopus]

Murdoch (msg 42) not sure what you mean by "off", but all the internal units have been off for months, and tripping occurs frequently when they are not on.

Murdoch (50) I don't know what a clamp meter is, but I would expect an electrician to have or obtain whatever is necessary?

Thanks again.

42 - thats very interesting so it rules the internal units "out" of the problem - but not the cabling installed for them.

50 - not all sparks have them, but I find them, in cases such as yours essential - so ask when you're trying to find a new spark - if they say "I don't need one" don't let them on site.

 

[Toneyz]

IMO there is an accumulation of leakage currents, insulation test maybe won't show until appliances/A C units powered up a leakage test would be a start.The neutral being on the wrong RCD side should have been ruled out ages ago.Swopping a few circuits around between both the RCD's may even the leakage current out between RCD's but as time goes on the leakage may get worse from the appliances with age I think Tel was right in his first post and the one regarding your electrician. Installing a new consumer unit with RCBO's or buying replacement internal parts to have a
main switch some high leakage circuits on RCBO's and a RCD protecting other circuits with MCB's or if costs permit all RCBOs another thing to consider is you have no more spare ways.

 

[Mjbarnard]

Ta - electrician previously supplied quote for swapping all mobs to rcbo's as one of the options. Not sure why we didn't do it - I think he wasn't certain it would solve it.

 

[Wilko]

Hi - if I understand your post #52 correctly all your problems stop if you isolate the air con units - or ?

 

[Mjbarnard]

Yes if I isolate the air con external units or turn the air con mcb's off OR leave the air con on and isolate the dishwasher (irrespective of whether it is plugged in or not).

 

[DPG]

A check on earth leakage is the way to go. You're going to be guessing otherwise. Check leakage on each air con unit.

Took me 10 minutes to type this as I have been drinking since 6pm. Bear with me if I don't make much sense.

 

[Wilko]

A check on earth leakage is the way to go. You're going to be guessing otherwise. Check leakage on each air con unit.

Took me 10 minutes to type this as I have been drinking since 6pm. Bear with me if I don't make much sense.

10 minutes ? I had to wait till morning