7 minutes ago, carlyai said:

Not too sure where the OP is up to in their fault finding progression, but, to me, a few things don't add up, or maybe I missed something?

Firstly the fault seemed to come on about the same time and the breaker couldn't be reset for a few hours.

Then while testing the breaker could be reset, not having to wait. What changed?

Placing the unit in Direct mode stopped the unit from tripping, OK could be a leakage fault, but initially, if it is/was a leakage fault, it seemed to clear after a few hours and the breaker could be reset. Strange fault (Ahhhh, those red ants) as the leakage fault seems to clear.

So at the moment, the SafetyCut doesn't trip in the Direct switch connection.

Now the OP is looking for a leakage fault by isolating loads and turning off breakers. Is that correct.

I'd still replace that SafetyCut with a newer unit. 

 

We will install another safety switch and will replace the wiring and the earth rod.

2 minutes ago, tlcwaterfall said:

We will install another safety switch and will replace the wiring and the earth rod.

Did you find some fault?

Also, it may be better to replace the SafetyCut with a normal 50 A breaker and replace the other breakers with RCB's. Then if an RCB trips it only shuts down that load and not the whole house.

I've got a whole house SafetyCut and slowely replacing all the final breakers with RCB's as when it trips, there goes all power not just the faulty circuit power. And, it always trips when we're not here. ????

51 minutes ago, carlyai said:

Did you find some fault?

Also, it may be better to replace the SafetyCut with a normal 50 A breaker and replace the other breakers with RCB's. Then if an RCB trips it only shuts down that load and not the whole house.

I've got a whole house SafetyCut and slowely replacing all the final breakers with RCB's as when it trips, there goes all power not just the faulty circuit power. And, it always trips when we're not here. ????

Electrician has been out twice and no faults have been found. Safety cut is very old and  electrician mentioned that the earth rod is not deep enough.  Replacing these items will hopefully fix the problem but no guarantees that will happen.

 

Appreciate your advice.

2 hours ago, bluejets said:

Not likely on earth leakage as it requires the imbalance to be detected on the "load" side of the torroid.

 

Yes, but anecdotally, a while back, whilst replacing a meter on an unearthed building close by, I accidentally shorted the live feed, and my house main breaker tripped.

1 hour ago, carlyai said:

Did you find some fault?

Also, it may be better to replace the SafetyCut with a normal 50 A breaker and replace the other breakers with RCB's. Then if an RCB trips it only shuts down that load and not the whole house.

I've got a whole house SafetyCut and slowely replacing all the final breakers with RCB's as when it trips, there goes all power not just the faulty circuit power. And, it always trips when we're not here. ????

That is quite possibly a good plan if the house electrical system is of uncertain quality, not so much if you have 30 MCCBs

 

 

On 3/1/2023 at 10:12 AM, carlyai said:

Also, it may be better to replace the SafetyCut with a normal 50 A breaker and replace the other breakers with RCB's. Then if an RCB trips it only shuts down that load and not the whole house.

Good advice. 

If you do, might as well stay up to date and do not use AC type RCBO's.

Other types are now available such as common type A.

 

On 3/1/2023 at 11:10 AM, NotEinstein said:

Yes, but anecdotally, a while back, whilst replacing a meter on an unearthed building close by, I accidentally shorted the live feed, and my house main breaker tripped.

Who can say what you did, one thing is certain, never work live.

Stupid is as stupid does.

Nothing to do with earth leakage systems.