RCD tripping in Consumer Unit

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You can also buy battery powered alarms, which plug in to the freezer circuit and warn you when power is lost.
One can, but as I've observed before, the last couple (maybe three or more) times I have suffered 'loss of a freezer', it has been due to failure of the freezer itself, without loss of (including 'tripping of') power. I therefore have temperature-operated alarms on all my freezers. However, they are only of use when the house is occupied, but I'm sure that one could arrange for such an alarm to produce alerts via e-mail or SMS etc. if one really wanted to.

Even then, if one is lying on a beach in the Maldives, I'm not sure that it's necessarily very useful to know that food in one's freezer back in the UK is 'going off' :) Insurance was designed to cover such occurrences. However, they are very rare. Loss of a freezer whilst a house is occupied is, itself, rare enough, so (unless one spends one's entire life globe-trotting) one would have to be very unlucky for it to happen whilst the house was unoccupied!

Kind Regards, John
 
So can I assume its not a straightforward exercise to put the kitchen ring onto a RCBO in a CU full of MCB's and 2 RCD's - shame!
It depends on the design of the CU.

Some CUs are laid out with a couple of non-RCD ways in addition to the two RCDs. If your CU has such a layout and is of a range for which parts are still available and the person who installed it left the wires long enough to reach the new RCBO then it is straightforward.

If your CU doesn't have such a layout then more reconfiguration would be needed, exactly what is possible would depend on the design of the CU.
 
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All good stuff...
If we assume that the o/s security camera is the problem, is there anything that can be done to make it less likely to trip the lighting circuit and hence the RCD?
To recap, its a relatively cheap unit on the o/s wall which catches a great deal of the prevailing weather and is powered through a plastic waterproof junction box and an inside wall switch.
 
All good stuff...
If we assume that the o/s security camera is the problem, is there anything that can be done to make it less likely to trip the lighting circuit and hence the RCD?
To recap, its a relatively cheap unit on the o/s wall which catches a great deal of the prevailing weather and is powered through a plastic waterproof junction box and an inside wall switch.

Your only options are to either to improve the weather resistance, or install a separate RCD circuit for it, or both.

It is well worth your making sure the 'inside wall switch' is a double pole irrespective of what else you might do. That would make it possible to reset the RCD to restore internal operation, even when the outside circuit had leakage on it.
 
Thanks for everyones help but I may have found the source of the problem.

Throughout last night the electricity supply was regularly cutting out, the smart meter was buzzing and doing all sorts of strange things and the RCD was also tripping. During the night, I saw that my neighbours still had power so I didn't think there was a supply problem. This morning, with no electric supply as well as a tripped RCD I contacted UKPN. They told me that they have had supply probs in my immediate are for the past few days which they are working on. This coincides pretty much exactly with when the RCD first tripped. They have now texted me to say that everything is now fixed.

My question now is why should one of my RCD's trip when the power is cut? Does it imply a faulty RCD?? Is this something I should get checked by an electrician??

Thanking you all as usual....
 
I lived on the Falklands for a time, and in the farms generators only ran twice a day, so the whole idea of a frost free freezer is out, as if just at end of defrost cycle when power goes off, it will not last until power comes back on, so all chest freezers used.

With a chest freezer looking at over double the time without power, so if freezer was running at 7 am when you leave for work, assuming relatively full, then if power trips as you leave the door, and you reset it at 6 pm, likely all food will be OK.

But with a frost free freezer as I found out to my cost, if after defrost cycle it fails to restart, you have less than an hour to do something. OK if at the point where it has just turned off the power fails you may still have 6 hours before there is a problem, but it is all dependent where in the cycle it fails.

So insurance and take reasonable steps, which to my mind is a dedicated RCBO to freezer, commercial you can get auto resetting RCD's but not permitted any more with domestic.

But the less on the RCD the less likely to trip, so we can reduce the risk, ensure any outside lights not on same RCD as freezer, so in many homes we have a kitchen ring final so with a high integrity consumer unit and the kitchen ring final on a RCBO the risk is much reduced.
 
... But with a frost free freezer as I found out to my cost, if after defrost cycle it fails to restart, you have less than an hour to do something. OK if at the point where it has just turned off the power fails you may still have 6 hours before there is a problem, but it is all dependent where in the cycle it fails.
Does that mean that with a 'frost free' freezer (I've never owned one!), if a power cut starts close to the 'worst point' in the freezer's cycle, then there is a risk that one may have have less than an hour before the temp of the contents rises to a level at which food will start to spoil?

If so, then that seems to be a fairly good reason for not having a 'frost-free' one (unless one wants to rely totally on insurance) since most 'true power cuts' (due to network faults requiring repair) will last a good bit longer than an hour.
... So insurance and take reasonable steps, which to my mind is a dedicated RCBO to freezer... But the less on the RCD the less likely to trip, so we can reduce the risk ...
All agreed, but with the two caveats I always mention:

(a)... In the absence of a power failure alarm, putting a freezer on a totally 'dedicated' RCBO-protected circuit increases the risk that freezer failure due to the RCBO tripping (if it ever does) may go unnoticed for a long period, and ...

(b)... Even with a power failure alarm, one will not be altered if the freezer itself fails, but without loss of power (due to RCD/RCBO tripping or anything else). That is why I always have temperature-triggered alarms on freezers - since, as I've said, the last 2 or 3 times (over a couple of decades or so) I have been at risk of (but have avoided) suffering loss of a freezer contents, it has been due to failure of the freezer itself without loss of power. An alarm which is triggers at, say, -10°C will give one a good few hours to address the problem.

As for the situation when the house is unoccupied, I leave that to insurance, since I'm not going to faff about with alarms which send me e-mails or text messages - not the least because, as I've said, it would probably only cause me anxiety if I were hundreds or thousands of miles away and probably unable to do anything about the problem!

Kind Regards, John
 
Does that mean that with a 'frost free' freezer (I've never owned one!), if a power cut starts close to the 'worst point' in the freezer's cycle, then there is a risk that one may have have less than an hour before the temp of the contents rises to a level at which food will start to spoil?

If so, then that seems to be a fairly good reason for not having a 'frost-free' one (unless one wants to rely totally on insurance) since most 'true power cuts' (due to network faults requiring repair) will last a good bit longer than an hour.

Frost free or not, even if you manually defrost - you would be in a mess if power was lost at the crucial moment.
 
Frost free or not, even if you manually defrost - you would be in a mess if power was lost at the crucial moment.
If you mean that one would be in a mess if a power cut occurred soon after one defrosted manually, then that's obviously correct - but that would require an extremely improbable coincidence, given that manual defrosting only takes a very occasional hour or three

On the other hand, as I understand it the 'defrosting cycle' of a frost-free freezer is quite short, so that far less improbable a coincidence would be required for a power cut to occur at a 'bad moment' in the cycle.

Kind Regards, John
 
Yes I was in the room when my freezer failed, so was aware of what had happened, I had a spare in garage normally used for beer brewing, so removed beer and turned on to freeze, and left around ½ hour for it to cool before transferring frozen stuff, thinking it would stay cool for a few hours.

However stuff at bottom seemed frozen, but top shelf was defrosted and decided not to take a chance with next shelf down.

The way a frost free freezer works is the cooling coils are behind a divider and there is a circulating fan, this means when working all food at -18°C does not matter where it is in the freezer, so much better than non frost free, when it goes to de-frost cycle the fan stops, so only the coils are heated behind the panel, and the condensate runs onto a tray on top of the motor, so once it restarts it evaporates with heat of motor, and there is a delay on the fan starting so cooling coils are cold before it runs.

It also means no cooling elements between shelves and draws, so you can fit really big items in like Christmas Turkey by simply removing draws or shelves.

But when it fails clearly heat raises so it goes to top of freezer, so items on lower shelves still solid frozen, only top defrosts, but in a way that is worse, as you can be unaware of the failure.

Mine show the switch on temperature until door is opened, so if there is a power cut I know how warm it got inside, but that does not happen with chest freezer, and clearly you don't open a freezer when a RCD has tripped until it has had chance to cool again, so you are in effect crossing your fingers unless it shows switch on temperature.

I know I had a rechargeable torch on same supply as freezer, with a power cut torch would light, so alerting me of the power cut, as I tend not to notice a lack of a light, only see it when a light comes on.

As to insurance ours requires us to not leave the house for over a set length of time, and when it failed were were looking after my mother, so had been out of the house for over a month, so could not claim.

Hence when I moved here I considered the £300 or so to restock freezer, although not full, and decided all RCBO was the way to go. We have had trips when the roof leaked, but not the supply to freezer, so yes having all RCBO has paid for its self.

But I fitted RCD's in old house around 1992 mark, and likely we have lost 5 freezers full of food in that time, some due to freezer failure so RCD not to blame, So may be £800 worth of food lost, but not all at the same time, and in 1992 did not have the option of fitting RCBO's as the consumer units then did not support all RCBO use. So lost around £30 per year not having all RCBO fitted, which is not that bad really.

I have had one even when the RCD may have saved me, I sawed through a cable not in safe zones I did not realise it was there, it may have saved some one in my family other times, but can't be sure, however it was enough to knock me out, but did not clearly kill me, so it may have saved my life, so thing RCD protection is worth it.
 
The way a frost free freezer works is the cooling coils are behind a divider and there is a circulating fan, this means when working all food at -18°C does not matter where it is in the freezer, so much better than non frost free, when it goes to de-frost cycle the fan stops, so only the coils are heated behind the panel, and the condensate runs onto a tray on top of the motor, so once it restarts it evaporates with heat of motor, and there is a delay on the fan starting so cooling coils are cold before it runs.

Oh, OK - so the defrost cycle could be fairly quick, I didn't realise that.
 
... I know I had a rechargeable torch on same supply as freezer, with a power cut torch would light, so alerting me of the power cut, as I tend not to notice a lack of a light, only see it when a light comes on.
Fair enough - that's just a type of improvised 'power failure alarm' However, as said, that won't tell you about failure of a freezer which is still receiving power.
As to insurance ours requires us to not leave the house for over a set length of time, and when it failed were were looking after my mother, so had been out of the house for over a month, so could not claim.
OK, but that's an extremely uncommon situation. Very few houses are left unoccupied for more than a month and, as you imply, most insurance policies will cover freezer contents (and the consequences of water leaks, wind etc.) for a period of non-occupancy of at least one month.
Hence when I moved here I considered the £300 or so to restock freezer, although not full, and decided all RCBO was the way to go. We have had trips when the roof leaked, but not the supply to freezer, so yes having all RCBO has paid for its self.
Fair enough. Since it's all probabilistic, it's obviously a gamble, so #experiences will vary'. In our case, helped by the fact that we have virtually always had over-temp alarms on freezers (and we haven't been unlucky enough for a freezer to 'die' whilst our house was unoccupied for an appreciable period of time), we have never (in ~50 years) suffered loss of the contents of a freezer because the freezer stopped 'working' (for whatever reason) - so, had we installed 'all RCBOs' purely because of the 'freezer issue', all of the marginal additional cost of the RCBOs would have represented a 'financial loss'.

One of the differences between us may be due to the fact that, apparently unlike yourself, we have virtually never (in the 30+ years we have had them) experienced any 'nuisance' trips of RCDs or RCBOs - what few trips we have experienced have been 'for good reason', nearly always related to water ingress (plus, of course, all those times I've touched L & E together on an SP-isolated circuit :) ), and never whilst the house was unoccupied for a significant period.

Having said that, if the 'nuisance trips' you experience are truly 'unexplained spontaneous events' (due to whatever), that can presumably happen with an RCBO dedicated to the freezer. More generally, one has to assume that the more residual current devices (RCDs and/or RCBOs) one has, the more often is one going to experience 'unexplained spontaneous trips' of one of them?
I have had one even when the RCD may have saved me, I sawed through a cable not in safe zones I did not realise it was there, it may have saved some one in my family other times, but can't be sure, however it was enough to knock me out, but did not clearly kill me, so it may have saved my life, so thing RCD protection is worth it.
Yes, we know that story. As you say, we will never know what would have happened in the absence of the RCD - although, if it 'knocked you out', it's quite possible that the effects of the shock removed you from the source (hence terminated the shock current' almost as quickly as an RCD would have done.

For what it's worth, as you know, I have for many years been asking the question of everyone, and every group of people (like members of this forum), I come across (which must total at least several hundred people by now) and, as yet, you are only one of two or three people who have reported that they had received, and survived, an electric shock which caused an RCD to trip.

Kind Regards, John
 
Oh, OK - so the defrost cycle could be fairly quick, I didn't realise that.
Never having had one, I'm uncertain, but the impression I get is that (given that the purpose is seemingly to avoid frosting up, rather than 'defrost' it once it's happened) the 'cycle' in these machines is very short, quite probably less than 24 hours in duration.

I may be totally wrong, but @ericmark seems to understand about these things, so perhaps can clarify (or correct me if necessary!).

Kind Regards, John
 

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