Latest RCD experiences

[MalcyB]

I just thought I'd pass on the latest experience I have had with RCDs.

Some time ago I posted about a problem with an RCD tripping at any particular time. I did all the usual tests on the circuits everything checked out ok. RCD tests ok Ramp test ok.

Tried to narrow it down to a time when things were on and in use. No joy there.

In the end we decided to change the RCD. On turning main switch off the RCD tripped, which it hadn't done before, I might be wrong and get told otherwise, but I have never noticed this to happen on any others I have done.

RCD was changed, all is now well. No tripping for about three weeks now.

The problem I have now is the RCD tripping gremlin has now moved into my house!!!

Four days ago we woke up to find the electric had gone off at around 4am, thinking there had been a power cut we stayed in bed! When we did get up we found one of the RCDs had tripped (17th ED board). I looked round for what might have been the problem found nothing so left it at that. Next morning RCD off again around 2am. Decided to test, all circuits on RCD side fine. RCD tests fine.

Went off again Sunday afternoon. Getting really frustrated now. headbang

The only things that were actually working during the night were the fridge and the freezer (BEKO!!!)

This morning I decided to rig up the freezer on a different circuit. no tripping since this morning!

---------- Post Auto-Merged at 18:46 ---------- Previous post was made at 18:33 ----------

Unbelievable. literally 2 minutes after posting this, the RCD tripped!! headbang

 

[binky]

For my own house I would defo fit RCBOs for each circuit, at least you might have some idea of where the problem is. Tripping when switching mains on and all circuits good has to be start up surge from some appliance, unless you are talking about all MCBs in off position?? Failing that check incoming neutral connection.

 

[Doc Hudson]

Not sure what you are trying to say here Malcyb? RCDs tested ok and are working correctly detecting earth faults, or RCDs not working correctly?

Doc H

 

[MalcyB]

No Binky you miss read, it was when I turned the main switch off.

---------- Post Auto-Merged at 19:13 ---------- Previous post was made at 19:07 ----------

The first one, where changing the RCD seemed to stop the problem tripping, even though it tested ok. I would have thought I would have found a problem in testing?

What's happening at the moment in my house, everything tested ok, but it seems to be one of those annoying ones that makes no sense. I've swapped the fridge & freezer over to different circuits to try to eliminate those.

 

[mikep]

You say when opening the main switch the RCD tripped, could it be a bad main switch one of the contacts not making a good connection and the RCD seeing it as a fault as when you went to switch it off it may have broken one contact first and the RCD detected this as a fault.

I would think this may be possible, what about a continuity check on it or just change it to be safe or even be a loose connection.

Just an idea.

Mike.

 

[Evans Electric]

Did you not see the RCD Tripping Gremlin following you Malcy, ? They only have little legs , you could have shook him off on the motorway.

 

[steptoe]

right, first off, opening or closing a main switch under load would be expected to trip an RCD,

especially when turning off,

a main switch could reasonably be expected to break Line first and make line last, so an imbalance would be very easily met.

you say everything is turned off,

being turned off is nothing to an RCD, unless you also mean via the Neutral, which I very much doubt,

9times out of ten it is a neutral imbalance that will trip an RCD, and as we all know N E is constantly connected,

BTW, RCBOs will not entirely correct this problem, merely hide it til it jumps up and bites you,

RCBOs in the UK are generally SP so still leave the NE connected to continue their daisy chain effect or perhaps even leave you exposed to possibly harmful voltages.!

DO NOT even consider fitting SP RCBOs in place of RCDs for a normal household scenario, they are simply no where near as safe,

they may seem less nuisance prone, but IMHO safety is more paramount than a little bit of annoyance.

 

[Evans Electric]

I just thought I'd pass on the latest experience I have had with RCDs. Some time ago I posted about a problem with an RCD tripping at any particular time. I did all the usual tests on the circuits everything checked out ok. RCD tests ok Ramp test ok.

Tried to narrow it down to a time when things were on and in use. No joy there.

In the end we decided to change the RCD. On turning main switch off the RCD tripped, which it hadn't done before, I might be wrong and get told otherwise, but I have never noticed this to happen on any others I have done.

RCD was changed, all is now well. No tripping for about three weeks now.

The problem I have now is the RCD tripping gremlin has now moved into my house!!!

Four days ago we woke up to find the electric had gone off at around 4am, thinking there had been a power cut we stayed in bed! When we did get up we found one of the RCDs had tripped (17th ED board). I looked round for what might have been the problem found nothing so left it at that. Next morning RCD off again around 2am. Decided to test, all circuits on RCD side fine. RCD tests fine.

Went off again Sunday afternoon. Getting really frustrated now. headbang

The only things that were actually working during the night were the fridge and the freezer (BEKO!!!)

This morning I decided to rig up the freezer on a different circuit. no tripping since this morning!

---------- Post Auto-Merged at 18:46 ---------- Previous post was made at 18:33 ----------

Unbelievable. literally 2 minutes after posting this, the RCD tripped!! headbang

Are we looking at the fridge then ? What make is the board by the way?

I've posted this one before but we had a mystery tripper on a new Crabtree board. RCD tests were OK . Our wiring was OK . We were investigating the Imm. Htr . and the boiler on the second visit to sort it .

I called the RCD a barsteward and tapped it with a driver , it tripped , reset , tapped the board, tripped. Then the little old lady says " Oh I meant to say, it always happens when the door slams .

Replaced it , no more call backs.

 

[Riggy]

right, first off, opening or closing a main switch under load would be expected to trip an RCD,especially when turning off,

a main switch could reasonably be expected to break Line first and make line last, so an imbalance would be very easily met

How can this cause a imbalance? If it did, every time we operated a single pole switch the RCD would trip.

 

[MalcyB]

Are we looking at the fridge then ? What make is the board by the way? I've posted this one before but we had a mystery tripper on a new Crabtree board. RCD tests were OK . Our wiring was OK . We were investigating the Imm. Htr . and the boiler on the second visit to sort it .

I called the RCD a barsteward and tapped it with a driver , it tripped , reset , tapped the board, tripped. Then the little old lady says " Oh I meant to say, it always happens when the door slams .

Replaced it , no more call backs.

I put the fridge on a different circuit last night with its own RCD, got up this morning the fridge was off. fortunately it is still under warranty so gettingn engineer out to it. The odd thing is it can be on for 10 hours without fault.

The board is a Hagger.

I posted this to see what experiences other people had had with trying to track down why an RCD would be tripping with what we sometimes assume for no reason. 99% of the time there is a logical explanation, it just takes time and a lot of patience.

 

[steptoe]

How can this cause a imbalance? If it did, every time we operated a single pole switch the RCD would trip.

totally different,

the SP switch is downstream so would affect the RCD differently,

think borrowed neutrals, all is well until that light is switched on.

BTW, it wasnt meant as a hard and fast rule, but it is a possibility,

I was merely trying to offer possible solutions to the OPs situation, which appeared to be quite peculiar with its randomness.

 

[Sidewinder]

fortunately it is still under warranty so gettingn engineer out to it

Doubt you'll get an Engineer mate sorry!

 

[batty]

I think these fridges and freezers with the auto defrost can be trouble had that a while back with one that had been in about 18 months think that what was randomnly tripping RCD any way haven't heard no more so it must have been that. Sorry steps i will carry on fitting RCBO boards i still think it is a better way than losing half the electrics in a house.

 

[MarkieSparkie]

Hi MalcyB, Is your fridge/freezer one of the Beko models of frost free fridge/freezers that are part of the current product recall notice. If effected it may be possible for the defrost timer (located at the back of the fridge) to fail, overheat and cause a potential fire hazard. This might in part explain explain your tripping issues, due to insulation breakdown and leakage. The cause appears to be an unsealed mechanical timer that collects some of the condensate instead of it being evaporated in the compressor tundish. For further information see link below:

Beko : Important Product Information for Fridge Freezers

 

[batty]

Hi MalcyB, Is your fridge/freezer one of the Beko models of frost free fridge/freezers that are part of the current product recall notice. If effected it may be possible for the defrost timer (located at the back of the fridge) to fail, overheat and cause a potential fire hazard. This might in part explain explain your tripping issues, due to insulation breakdown and leakage. The cause appears to be an unsealed mechanical timer that collects some of the condensate instead of it being evaporated in the compressor tundish. For further information see link below:Beko : Important Product Information for Fridge Freezers

some lec ones involved too i think.

 

[SLIPSHOD & SLAPDASH]

I have had an Rcd tripping on turning off the supply a few times. Its always been a motor thats caused it but i read on another forum this has happened to several people & a fluorecent choke was the fault.