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| Rashers Member Since: 21 Jun 2015 Location: Norfolk Posts: 3341   
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I assume the 'Main Switch' you talk of is an RCD (Earth Leakage Circuit Breaker).
Now if that's assumed right, those things measure an imbalance between your live wire and neutral wire. It assumes that if these are not similar, the electricity is going to earth. That's how they trip. Lap top transformers (or any other kind of transformer / motor / heating element etc.) leaks a certain amount (very small amount) of power to earth (in a large office full of PC's this can sometimes be a real problem). I would assume that perhaps this laptop power supply is leaking a bit, and there may be other things you have plugged in which might just push the power imbalance to trip the RCD. Again, without knowing what your electrical distribution board looks like or how it is configured, it sounds as if you miniature circuit breaker which supplies this circuit is tripping as well. That is more difficult to fathom. MCB's have a thermal trip (a bi-metallic strip) and a magnetic trip within most of them. The first is a bi-metallic strip that heats up as the load increases to the point when it will operate. The second is a coil just like a solenoid or a relay with an iron aperture. Power increase, magnetic field in the coil increases, then moves to the point when it trips. That shouldn't have operated. Your electric underfloor heating will also have a small leakage to earth so everything I have described above would get worse with your heating on. That's where I am stumped as it seems to have helped. As a guess, maybe increasing your load on your electrical supply is creating a bit more of a voltage drop on the mains supply, and this is enough to stop the RCD from tripping (I'm clutching at straws, that's a pure guess). I think I would be thinking of replacing that power supply (don't sling the laptop, try googling a new one). Two other things worth looking at:- 1. Your toaster. Shake the crumbs out as the carbonised bits in the base of a toaster can cause havoc if there is an electrical track to earth. 2. Have you nailed any pictures up on the wall since this all started. A pin nail above a switch or socket doesn't necessarily have to pierce the cable completely. A nail touching the bare earth wire in a pvc twin and earth cable and pushed up against the neutral / live cable will also trip an RCD. I have made quite a lot of assumptions in all that. I hope that helps  |
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16th Nov 2017 11:09pm |
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| What puddle? Member Since: 25 Oct 2013 Location: Reading Posts: 952
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Thanks very much for that
Nothing is ever allowed to be hammered into my walls! I completely rebuilt the house over the past 11 years but I let a sparkie do all my electrics (Mrs Puddle's uncle, so it's almost free). He can't understand it either - says it must be the charger on the laptop lead. But it doesn't explain why it hasn't happened since we're drawing all the extra kWhs the past six weeks or so. Something odd happened the other day, too. I have put under-cupboard coloured LEDS under the kitchen units. They were switched on the other afternoon, and the main trip tripped - but none of the individual trips. It happened just the once. I love the idea of trips, rather than the fuses I remember in our old house, but they seem too ready to put the power out at the slightest provocation. Having said that, I've had eight electric shocks in my life (Mrs Puddle says it explains a lot) and I'd rather not have any more.
Re: the voltage drop. The amp draw is quite a bit, some 48 amps minimum, sometimes perhaps close to 60. I don't know if that helps. The laptop is a few years old now, and has to be re-charged a lot, so if it gives trouble in the spring, it might as well go. Now left. |
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16th Nov 2017 11:42pm |
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| Rashers Member Since: 21 Jun 2015 Location: Norfolk Posts: 3341
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We used to get issues with 6 Amp Type B breakers (MCB's) tripping when the old incandescent light bulbs used to blow. The point of blowing used to spike the circuit with enough fault current to blow the MCB. This was easily remedied by installing a 10 Amp! If the circuit was wired in 1.5mm2, easily enough protection in a house.
LEDs use drivers to power them. these can be internal or external to the lights. Again, this sounds like earth leakage again. If Mrs Puddles Uncle has an RCD tester, see if he can test the RCD operation (this does more than pressing the test button which just operates the mechanism rather than making sure it operates in the right time. There is a possibility it could be too sensitive (another stab in the dark there without any evidence) Out of interest, I am assuming you have an RCD, do you know what the rating of the device is? If it is an RCD it will have an Amp rating and a mA rating, first figure maximum load, second figure maximum allowed earth leakage. Assuming it is an RCD on the mains, if it is a 30mA it would probably be a bit too sensitive for an incomer (although I lived in a house for years supplied via a 30mA RCD). It was done in the past, but is not encouraged now. I had to fit a timed delayed RCD on my mains as I had a similar problem to you. Stripped my circuits down, tested each circuit and never did get to the bottom of it. I'm sure Mrs Puddles Uncle would be able to source one of those if it may help? As I said before, quite difficult to recommend anything without knowing the details of everything. A bit of a P.I.T.A for you  |
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17th Nov 2017 12:00am |
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| AMBxx Member Since: 24 Jul 2016 Location: York Posts: 985 
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We had a similar problem. One light switch would repeatedly trip the RCD. Electrician did his incantations and decided it was due to the vast number of things we have plugged into wall sockets. I work from home and have 14 things plugged into 1 socket (PC stuff).
Solution was to just upgrade the board. Didn't cost much and we also found out that some of our 'ring mains' were just very long spurs.  |
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17th Nov 2017 8:22am |
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| MartinK Member Since: 02 Mar 2011 Location: Silverdale (Lancashire/Cumbria Border) Posts: 2664 
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What laptop charger? I have a couple of spare HP ones... Defender "Puma" 2.4 110 County Utility (possibly the last of the 2.4's)
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17th Nov 2017 8:35am |
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| What puddle? Member Since: 25 Oct 2013 Location: Reading Posts: 952
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 It is a HP
Mine says 'Rev:A02 4X19317902' It's 45 watt. Now left. |
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17th Nov 2017 9:39am |
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| ARC99 Member Since: 19 Feb 2013 Location: North Yorkshire Posts: 1831 
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I had a similar problem with my Sony phone chargers , plug in to the mains before phone and the power would trip. I couldn't upstand why until I was talking to my tame electrician next-door neighbour. He suggested that I read the instructions that came with the phone as he was sure it would say something along the line of connect phone first than insert into power socket. I checked and he was right and I was using an in switched socket. Don't make old people mad.
We don't like being old in the first place, so it doesn't take much to  us off.
Richard |
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17th Nov 2017 11:41am |
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| Rashers Member Since: 21 Jun 2015 Location: Norfolk Posts: 3341
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Tame Electrician? Where the hell do you find one of them from?
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17th Nov 2017 12:09pm |
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| dorsetsmith Member Since: 30 Oct 2011 Location: South West Posts: 4554 |
laptop charger are mostly switching mode power supply's and will cores this problem by power inrush on power up and the RCD search coil seeing power going out and not retuning on the neutral with in its trip time will open up the contacts of RCD
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17th Nov 2017 12:24pm |
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| Intercept Member Since: 27 Feb 2017 Location: Suffolk Posts: 587 
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Some power supplies, especially those with toroidal transformers, have a very high inrush current at switch-on. Many LED drivers also exhibit this behaviour. Most MCBs fitted to consumer units have a Type B trip curve, but Type C is also available to solve the high-inrush problem. I have used the product linked below to solve LED driver derived issues on lighting circuits. The same approach might be appropriate in your case if its inrush related. This is the 6A version, but they are available in various ratings up to 50A.
https://www.tlc-direct.co.uk/Products/WYNHXC06.html |
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17th Nov 2017 12:24pm |
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| ARC99 Member Since: 19 Feb 2013 Location: North Yorkshire Posts: 1831
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Next door Don't make old people mad.
We don't like being old in the first place, so it doesn't take much to us off.
Richard |
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17th Nov 2017 12:40pm |
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| discomog Member Since: 09 May 2015 Location: Notts/Lincs Border Posts: 2496 
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I experienced nuisance tripping of a MCB with discharge flood lighting at my stables. Cured the problem by replacing the B type with a C type. If you suspect an inrush problem then it may be worthwhile just changing the MCB as they are a relatively low cost item. Defender 90XS SW
Mini Countryman Cooper S Morgan Plus 8 |
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17th Nov 2017 1:38pm |
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| Rashers Member Since: 21 Jun 2015 Location: Norfolk Posts: 3341
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If you can get type C breakers, it is indeed a good fix. Sadly there are quite a few domestic distribution boards (older one's and bargain basement ones) where a type C breaker isn't an option because they never produced them.
Sometimes you can get lucky and find an MCB from a different manufacturer with similar dimensions and busbar connections which fit in your distribution board. |
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17th Nov 2017 1:48pm |
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| What puddle? Member Since: 25 Oct 2013 Location: Reading Posts: 952
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Thanks everyone, lots to report back to my sparkie, there, especially about the power inrush and not coming back on the neutral. Now left.
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17th Nov 2017 6:29pm |
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