Random RCD tripping out

[Neilshore]

Good evening all.

I’m a new member and found this place by searching for some info on a problem that has developed. I used to be a sparky in the Navy so have some experience, did my first year but never completed the training.

So back ground.

No issues for over 3 years. Did have a RCCB protected board with during the fault finding/diagnosis stage I changed to a Split RCD board same fault exists.

So the issue is the RCD now trips out under load it was the RCCB before the CU was changed… turn the cooker on (it’s own circuit) RCD trips, wife plugged in the hoover on the downstairs ring.. RCD trips, plug in the freezer, kitchen ring… RCD trips, so it’s seams to be when there is an increase in load, we are sitting here watching TV no issues. Central heating works, Fan upstairs in the bedroom works and so on, so very low load appliances (maybe the fan is a little heavier load, it’s just a floor fan)

now this also started this week (3 days ago to be precise) now Monday we started to have some work done, new drive way install so some excavation work on the drive, a new patio and some fencing. It’s the excavation work that concerns me, is it possible they have damaged a cable under ground unknowingly? I’ve been here with the guys and haven’t seen anything ( cable wise)

I’ve spoke to UK power network and they are sending someone out tomorrow, fridge stuff is written off but managed to run an extension lead to the neighbours to run the freezer and that been on for a few hours now with out incident so it’s not the appliances.

Some help or ideas as what to look at next please. No washing machine or any slightly heavy use appliances can be used.

Many thanks

 

[James]

Classic symptoms of a neutral to earth fault on a circuit. Could be any circuit even one not on the rcd that is tripping.

 

[Neilshore]

Classic symptoms of a neutral to earth fault on a circuit. Could be any circuit even one not on the rcd that is

Any reason you can think of why it would just start up now?

 

[James]

Water damage or a faulty appliance
look at switching off oven and immersion heater instant see if problem goes away.
(at the isolator, not the fuse board)

 

[brianmoooore]

Water damage or a faulty appliance
look at switching off oven and immersion heater instant see if problem goes away.
(at the isolator, not the fuse board)

AND make sure everything is unplugged - not just switched off at the socket.

 

[Neilshore]

AND make sure everything is unplugged - not just switched off at the socket.

Tried all of these suggestions already I’m afraid.

It’s different appliances on different circuits and it still trips out. Hoover on the downstairs ring, cooker on its on circuit, freezer on the kitchen ring. It’s only when a load is applied, the cooker is on now… but when you turn it on to cool it trips, plug the hoover in it’s fine, turn it on, it trips, fridge and freezer trip straight away as the compressor kicks in. I’m at a loss as to what it can be. As I said originally it’s only started since the building work out side. Could they have caught a cable and not known about it?

 

[littlespark]

If the driveway guys caught a main cable, it would blow out half a street… it would have to be an outgoing cable to affect your board, ie to a shed or something.

Check outside lights and sockets for water egress. Exposed cables for damage… impact damage, rodents etc

Now it’s a split rcd board… is there one or two RCDs? Is it only one of them that trips?
Photograph of that please. Perhaps just a weak RCD?

Was the installation tested when the board was changed? It really should have been, and this fault may have been found earlier.

Have you got a Smart Meter? Sounds crazy, but it has happened before that smart meters can trip out an rcd somehow. (Search threads on forum)

Some electricians carry a earth leakage clamp meter which is sensitive enough to detect the tiniest differences. Maybe employ a spark to have a look.

 

[Neilshore]

If the driveway guys caught a main cable, it would blow out half a street… it would have to be an outgoing cable to affect your board, ie to a shed or something.

Check outside lights and sockets for water egress. Exposed cables for damage… impact damage, rodents etc

Now it’s a split rcd board… is there one or two RCDs? Is it only one of them that trips?
Photograph of that please. Perhaps just a weak RCD?

Was the installation tested when the board was changed? It really should have been, and this fault may have been found earlier.

Have you got a Smart Meter? Sounds crazy, but it has happened before that smart meters can trip out an rcd somehow. (Search threads on forum)

Some electricians carry a earth leakage clamp meter which is sensitive enough to detect the tiniest differences. Maybe employ a spark to have a look.

I’m still searching at the moment no signs of any water or rodent damage, no smart meters, and only 1 side of the board trips. It’s a brand new board, so don’t think it would be a weak RCD. I’m gonna have to get someone in I think.