I think this was often covered in the last but one forum where I never took much notice of the subject. But now it has happened to me! Suddenly interested!
My 15kVA single phase electricity comes in at my front gate, protected by a trip switch from EDF. From here the electricity is distributed to thee places within the property.All three places have dist. boards fitted with quality 30mA trips etc.
Normally perfectly ok, until I go away for two nights and then come back to no power around the property. All the local distribution boards perfectly ok, with no tripped switches anywhere. but the main EDF switch had tripped. Reset it and all fine again.
Is this situation indicating a fault at the EDF supply? Should I tell them (will they listen..)?
Hi Hal. I don't think it could be a fault with the edf supply. I would think it is either an earth fault between the main edf switch and one of your distribution boards, or you are exceeding your power limit (puissance souscrite).
Post by robertarthur on Dec 4, 2021 14:46:30 GMT 1
Hal, with your branchement long you'll have your compteur and disjoncteur de branchement (DB) in your coffret de branchement. As soon as your meter is a Linky, this smart meter will take care of overloads (puissance souscrite) and shorts. Your DB only functioning as a mechanical on/óff switch and taking care of fault currents to earth of more than 500 mA. Sometimes nuisance triggering. Question: old meter or a smart meter?
Post by robertarthur on Dec 4, 2021 15:33:47 GMT 1
As they age these DBs sometimes show a shift in their tripping tresholds. Life expectancy about 15 to 20 years. Sometimes much, much longer, a very old DB (650 mA). These almost shorts to earth don't disappear overnight, as soon as you try to get the power back again these DBs don't give you the green light. Being away and almost no power consumption makes the overload scenario less likely. Measuring the isolation resistance of the wiring between the coffret outside and the three tableaux électriques is something to do, the beginning of an answer sur place. Nuisance triggering still a possibility, any ENEDIS grid maintenance going on there?
No, no one else on the property. It is not a Linky meter yet.
Explaining a bit further, the three distributions are
1. To The gites, currently with everything off except the solar panel water circulator which is minimal draw. 2 To the Gite swimming pool feeding a 1hp motor and a salt generator, but these are programmed to come on at cheaper night electricty (I might check this though, as the clock can run a tad slow) 3. To the main house, where the total amount of appliances does exceed the 15kVA, BUT I have a little box - forget the name - that distributes the power in a priority sequence so that the 15kVA is never exceeded.
The cameras sent me a mail at 12.29pm that they lost power. At that time only the Aga and incidentals would be drawing power - say 15A max? (OK, my immersion heater is on 24/7 but highly unlikely it would have kicked in) so from what you all say, it is an earth issue rather than a power rush. Sounds like I should get someone out to check the earths are good around the place. I presume EDF look after their own earth, yes? I guess if I get a professional person out to check the earths, s/he will be able to deal with the EDF earth?
You say that another reason could be a power rush exceeding the contract. Am I correct in assuming then, if such a power rush occured, the various trip switches on local didtribution boards would be un affected, and only the main EDF breaker would trip?
The three distribution boards will all have disjoncteurs for each circuit. If the power on any of these circuits exceeds that disjoncteur rating then that circuit will trip. The main edf switch takes the full power from the whole premises. If this power exceeds your puissance souscrite, 15 kVA in your case, then the edf switch will trip.
Post by robertarthur on Dec 4, 2021 17:06:08 GMT 1
Hal, for the main EDF breaker to trip you would need a lot of power, even more than your 75 amps max, in real life probably somewhere around 90 amps. Back in time, as explained in the past on several other forums: the old thermal/magneto EDF main breaker is a rather friendly creature, it takes overloads with ease, so in practice you have headroom available up to 130 % of the nominal puissance souscrite. It measures the current consumption downstream of everything that has been switched on.
Checking the earths: the RCDs - interrupteurs différentiel - don't need earth to sense a fault current. They only measure the difference between incoming and outgoing currents. No connection to earth needed, there is a little resistor inside to provoke an unbalance between the two currents to test the mechanism. Checking the resistance of your earth rods is of course always a good idea, lower than 100 Ohms, but in this case it would not be of any help I'm afraid.
The ENEDIS (grid, EDF=production) is responsible for the earthing of their high voltage transformers (less than 1 Ohm), the client for the earthing of his/her installation électrique.
Wiring outside, to the swimming pool: always vulnerable. Something to have a closer look at, or switch off for a few days and see what happens.
That corresponds to one of the plage d'horaires that the tarif switches to HC and the HP/HC relay would change state closing the circuit which should be fed from a 2amp disjoncteur in your tableau.
Knowing how bodgy some of these are wired up it would not surprise me to learn that the cabling was an afterthought and is powered from the main disjoncteur feed, a seperate cable ran with the main supply cable to the house or gite, probably not in a seperate gaine, maybe a join in the cable in a flooded gaine or damaged insulation etc etc. A combination of those would cause a 500ma + earth leakage at precisely 12.30 am.
Reading again I see you are indeed on HP/HC, do you know what time it usually switches? Allow an hours difference for winter time or your security camera app using a different timezone.
I would definitely investigate the HP/HC switching circuit, the contactor is in your EDF compteur CBE outside, to have been wired correctly a pair of cables should have been run from a 2 amp disjoncteur on one of the tableaux, if that has been done then it would never trip the main 500 or 650ma disjoncteur d'abonnée, I suspect it may have been done by someone in the past in an expedient but unsafe manner.
I am now back a full day and not changed anything other than throw back up the EDF switch, and nothing untoward has happened, even in the evening when all the various underfloor heating elements kick in.
I shall still have the earths checked out as you all suggest, and if it stops raining tomorrow, check the swimming pool.
Can it be such a thing as a 'power surge' or the like at the EDF end?
Post by robertarthur on Dec 4, 2021 18:33:50 GMT 1
Hal, what's in a name, power surge? A DB is not a voltage sensing device, switching off when the voltage exceeds a certain limit. It doesn't protect your equipment against voltage spikes, lightning induced or otherwise, it's not a substitute for another guy by the name of parafoudre. A DB has also not been designed to switch off during brown or blackouts. More information about the Disjoncteur de Branchement, also from the depths of the internet memory.
No, nothing changed other than hard-wiring of towel rails, an Australian socket for hair drier, and reduction of MCB ratings for sockets to counter anyone with these new fangled cars that take petrol from a socket The hot water for the gites is exactly as you showed me all those years ago! (But now, they are all opff for the winter...)
BUT, this morning some more info: I happened to be awake at 04:00 when the green led showing the under floor heating was armed and ready, clicked off! Aha! checked the house and everything was off. Now the only things drawing power were, The fridge freezer, computer and printer in sleep mode, Aga. Everything else was definitely off or, like the UFH, armed but not drawing working power. So my mind was set on the Aga.
In the morning I noticed that yes, the main EDF switch had tripped, BUT, also tripped was the 30mA ID that controls the HC contactor, HC power and the three way slide switch for the water. The MCBs for the power and HC contactor did not trip. I have the slide switch set to 'always on' and rely on the thermostat to switch in the immersion when needed. Not much sun around here the past week, so I guess it has kicked in a few times - and maybe kicked in at 12:29 the other day and 04:00 this morning and set it all off. I see why a faulty immersion coil might trip something on my local board, but can it in any way set off the EDF switch...?