stevegough
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 posted on 12/6/10 at 08:22 AM |
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240 volt problem
I'm not sure if I'm allowed to ask this sort of question here, but if not, I'm sure someone will soon set me right..
I have an intermittent fault on my one of my ring mains - it trips the RCD on the board - last time about a fortnight ago. I had suspected the RCD,
but I had that tested yesterday by a 'leccy - its not that.
I will have to wait until it starts tripping again to narrow it down, but I need to be alerted as soon as it trips.
Question:- how can I rig an alarm up to tell me when the mains has tripped?
Even better - is there some way of getting a text message / phone call for a mains trip?
Otherwise, freezer stuff is in jeopardy! Especially if we are away for a couple of days....
Any ideas folks?
Regards, Steve.
Luego Locost C20XE.
Build start: October 6th 2008.
IVA passed Jan 28th 2011.
First drive Feb 10th 2011.
First show: Stoneleigh 1st/2nd May 2011.
'Used up' first engine may 3rd 2011!
Back on the road with 2nd engine may 24th
First PASA mad drive 26/7/11
Sold to Mike in Methyr Tydvil 19/03/14
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cliftyhanger
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| posted on 12/6/10 at 08:34 AM |
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I am not an electrician, but still I cannot see a simple was of rigging an alarm. Only thing I can think of is a "non maintained" light,
they are used for emergency lighting should the mains fail, so they switch on when the leccy goes off....or rig something similar. But nothing simple
at all.
I would suspect an appliance is tripping the rcd, fridges are a common culprit. Guess they can be tested for earth leaks. Otherwise intermittent trips
are a nightmare.
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prawnabie
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| posted on 12/6/10 at 08:37 AM |
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fix a pushbutton to the fuse so the lever pushes it down when it trips?
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MakeEverything
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| posted on 12/6/10 at 08:44 AM |
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A No volt relay to a battery powered claxon.
Mains fails, and the relay makes contact, sounding the alarm. Simple, and will cost about £10. A non-maintained fitting will cost you between £15 and
£50.
Kindest Regards,
Richard.
...You can make it foolProof, but youll never make it Idiot Proof!...
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JoelP
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| posted on 12/6/10 at 08:48 AM |
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have an emergency light plugged into a circuit on the rcd, it will come on when the power goes off.
Do you have any socket outlets not on the rcd? Ie upstairs circuits? If so you could run an extention lead down to the freezer to cover that
aspect.
Anything with a heating element is a possible culprit, especially irons/ovens.
If you cannot locate the fault, and it keeps on tripping, you might want to seperate the circuits onto a few rcds, maybe via rcbos. £30 a time though
so it could cost over 100 by the time you're done.
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BenB
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| posted on 12/6/10 at 09:01 AM |
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If you're not keen on mucking around with 240v have you got a transfomer for your doorbell.
You could splice into that (usually 9v). Then all you'ld need is
1) spare car battery
2) spare car horn
3) spare 12v relay
Simples
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MakeEverything
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| posted on 12/6/10 at 09:10 AM |
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You really need to find the fault. RCD's generally operate for a reason - particularly as you have ahd the RCD checked.
They operate as a safety device, so if you are plugging your suspect appliance into a non RCD protected circuit, then you could damage something or
evn injure someone.
Its not jsut heating elements that break down. RCD's operate on earth fault, so it could even be the compressor within a fridge or freezer.
I went to a house the other day, and someone had disconnected an appliance and left it behind a cover plate un-terminated. The conductors eventually
started to touch the back box and caused an intermittent tripping of the RCD which was also U/S. Would have been a nightmare to find if it wasnt in
such an obvious place.
Kindest Regards,
Richard.
...You can make it foolProof, but youll never make it Idiot Proof!...
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Mal
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| posted on 12/6/10 at 09:13 AM |
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If you have a mains powered electric clock and you get a trip that stops it, when you come home a few hours later just subtract the clock's time
from the actual time. Simples!
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austin man
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| posted on 12/6/10 at 09:52 AM |
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is there a common factor in all of this? ie does it happen wheb the irons turned on, you boilthe kettle etc , do any of the sockets show signs of
arcing. As stated previously its normally down to an appliance
Life is like a bowl of fruit, funny how all the weird looking ones are left alone
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big_wasa
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| posted on 12/6/10 at 09:52 AM |
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Have you got an immersion heater for hot water ?
That would be my first port of call.
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SteveWalker
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| posted on 12/6/10 at 12:53 PM |
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Laptop connected to old phone with pay as you go sim. Program to send a text on loss of mains power?
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Andy W
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| posted on 12/6/10 at 03:22 PM |
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Might be wrong, but I seem to remember talking to someone about PAT testing, who said fridges & freezers can have a slight leak to earth and still
be perfectly ok, but may trip a RCD for this reason they wouldn't have them on an RCD protected ring.
Andy
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Trev Borg
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| posted on 12/6/10 at 11:28 PM |
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The RCD works on a balance coil. what goes in, must come out.
Basically I iron core with an incoming winding on the live and an outgoing winding in the neutral. It also has a trip coil.
The incoming and out going coils oppose each other and if everything is is balanced then there is no current flow in the trip coil, and it will not
operate. If there is an earth fault in your installation then current may flow to earth, the return coil has less current than the incoming coil,
magnetic flux is generated in the iron core, which induces current in the trip coil, and she trips.
So in theory there must be an earth fault.
BUT, RCD's generally come in two sizes, 30mA and 100mA, 30mA to protect portable appliances and 100mA to protect fixed appliance.
If a number of appliances connected to the ring main in question all have an amount of leakage, then the combined leakage may cause the RCD to
trip.
The RCD's are tested by making sure they do trip when the have the right amount of leakage applied to them, but not trip when only half the
rated value is used. So a 30mA trip may trip at 16mA and test fine.
Go round plunging as many of the normal appliances in as you can to see if anything trips it. Just keep adding to it instead of doing one at a
time.
One other reason that it may trip is 'external influence'. If for any reason you suffer from flickering lights, or sudden lost of supply
from your supplier, then it has been suggested the ever increasing number of capacitors in modern appliances may suddenly discharge, causing an
imbalance in the RCD and trip it.
Bored yet? you should be
Before you judge a man, walk a mile in his shoes.
By that time, who cares.
You're a mile away, and you've got his shoes
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stevegough
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| posted on 13/6/10 at 09:05 AM |
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First of all, Many thanks for all the helpful replies over the last 24 hours - and no, I am not in the least 'bored yet' as Trev Borg
asked...
....to answer some of your questions.
ALL the sockets in the house and garage are covered by the RCD - so I can't protect the freezer that way. (JoelP).
Doorbell is a battery one - but I get the drift of the idea. (BenB).
There is no sign of arcing at any point - [sockets and plugs]. (AustinMan).
No Immersion heater. (Big_Wasa).
Haven't got a laptop - but I like the idea!! (SteveWalker).
The RCD is a 30mA one, and yes, it one one of the things the 'leccy mentioned that it is very likely to be a bit of leakage on a couple of items
combined which is causing the trip. (Trev Borg).
A few of you have mentioned fridges and freezers (esp AndyW) - as I have one of each on this circuit, I might try taking them onto the other side of
the board (non-RCD area). (I moved them both onto another circuit last week and haven't had a trip since, but that doesn't prove
anything!)
I'll post again when I get to the bottom of it - and I WILL!
Thanks again for all the help, guys (and gals?).
Regards, Steve. 
Luego Locost C20XE.
Build start: October 6th 2008.
IVA passed Jan 28th 2011.
First drive Feb 10th 2011.
First show: Stoneleigh 1st/2nd May 2011.
'Used up' first engine may 3rd 2011!
Back on the road with 2nd engine may 24th
First PASA mad drive 26/7/11
Sold to Mike in Methyr Tydvil 19/03/14
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