Freezer tripping electrics?

ka7e

Section62 said:

Turned off, or unplugged?  To trace the cause of tripping the appliance needs to fully isolated from the supply, as it is possible for enough current to flow through the neutral wire to earth to cause the RCD to trip.  If the freezer is just turned off without the neutral connection also being isolated then the fault could still occur. (if the issue was something like a clock/timer triggering the anti-frost, then backup power or charged capacitors could be enough to momentarily close a relay or similar)

Can the solar panels be fully isolated?

Ah, yesterday I unplugged it, today I just switched it off. I have a fuse marked "Solar" on that side of the RCB, but it was dark both mornings at 6.30.

WIAWSNB

ka7e said:

Section62 said:

Turned off, or unplugged?  To trace the cause of tripping the appliance needs to fully isolated from the supply, as it is possible for enough current to flow through the neutral wire to earth to cause the RCD to trip.  If the freezer is just turned off without the neutral connection also being isolated then the fault could still occur. (if the issue was something like a clock/timer triggering the anti-frost, then backup power or charged capacitors could be enough to momentarily close a relay or similar)

Can the solar panels be fully isolated?

Ah, yesterday I unplugged it, today I just switched it off. I have a fuse marked "Solar" on that side of the RCB, but it was dark both mornings at 6.30.

The inverter - where is it located? - should have both DC and AC isolating switches. You'd only have to turn off the AC - that will shut it down and completely isolate it from the mains. It will likely be a large, possibly red, turn switch with a hefty clunk. 

There is no harm from doing this - your PV won't mind. 

Heedtheadvice

As indicated in several posts ( including my epistle!) It could be anything on the circuits supplied through that RCD that you have latterly mentioned. It can be something that you logically would think is timed but is not primarily but is a  secondary effect such as movement or evapouration from heating affecting some equipment- not that I am suggesting that is the cause.

Do try isolating whatever you can on those circuits ( disconnecting  appliances or turning off isolators...not just switches!). That could eliminate many devices being that cause of being affected. It may leave you with just a few things still working that indicate where the fault lies....or not. Could be a long process to find individual items as the cause...or not find anything specifically!

However I think an electrician to test insulation of the circuits and devices will be a much faster way given the infrequent but seemingly non random tripping you are experiencing. The sparks could test the RCD too and change it if in the unlikely event it does prove overly sensitive.

ka7e

Yeah, I've admitted defeat and called in the sparks. I'll update if we get to the bottom of this conundrum!

Scrounger

ka7e said:

Yeah, I've admitted defeat and called in the sparks. I'll update if we get to the bottom of this conundrum!

Good decision, I'm sure they'll solve it.  Please let us know the outcome.


Scrounger

GlitterMedusa

How old is your RCD?
I had nuisance tripping from mine a few weeks ago, couldn't pin it to a single appliance or socket or circuit but it was a combination of any 2 appliances across any circuit that would do it. My electrician checked things and put it down to the RCD (part of a c. 1990 consumer unit) starting to fail. It's obviously impossible to find spares other than 2nd hand stuff of unknown quality, so I ended up having a shiny new CU with the latest everything installed. No problems since 

ka7e

GlitterMedusa said:

How old is your RCD?
I had nuisance tripping from mine a few weeks ago, couldn't pin it to a single appliance or socket or circuit but it was a combination of any 2 appliances across any circuit that would do it. My electrician checked things and put it down to the RCD (part of a c. 1990 consumer unit) starting to fail. It's obviously impossible to find spares other than 2nd hand stuff of unknown quality, so I ended up having a shiny new CU with the latest everything installed. No problems since 

Whole house was re-wired 6 years ago. CU was moved as it was in a storeroom we converted to a shower room. Since then we have added solar panels, an extra heater for bathroom, outside sockets and an outside light. I'm using the company that has done all the previous work bar the re-wire - and he was a former employee of theirs.

GlitterMedusa

Ah so your CU is young enough to be unlikely to be the issue. I hope your sparky finds the problem, and that it's an easy fix!

WIAWSNB

A possible solution would be to replace your MCBs, just the ones on power circuits, with RCBOs. These are an MCB/RCD combo, so any circuit that might have a 'leak' will trip only that circuit, and leave the rest unaffected. This way it's less of a nuisance, and will also make tracing the culprit easier.
In actual practice, it'll likely sort the issue, as each breaker will now be within the tripping current, rather than one main RCD trying to handle the accumulated leaks, and failing.