EDF Heures Creuses, switching system for hot water heater

[Martin963]

Can anyone advise please - the switching system that turns our hot water heater on at the start of les hueres creuses seems to have stopped working.   Normally there is a resounding "clunk" from the fusebox at 22.27 each night,  and a re-assuring hum then emanates from the control switch for the next eight hours.    However,  arriving a couple of days ago I realised that on our first night this had not happened,   so put the control switch on "over-ride"   (marked as position I,  the other two positions are AUTO and 0) and was able thereby to turn on the heater.   (En passant - and for those familiar with the system - normally the switch will not "latch" in posistion I during the heures creuses,   luckily ours now does under these "fault" conditions).

I haven't as yet delved into the fusebox wiring,   but (from what I remember of the situation from when I did do some phase load rebalancing many years ago) there is a 2A fuse associated with the control switch (which I have checked as is intact) which has to be in circuit for the automatic switching to happen.   The three phases coming out from the automatic switcher then pass down to the cellar where they are separately fused before the heater itself.

Rather like with ADSL problems,   at this stage I don't know whether to ring EDF about the problem,  or contact an electrician,  or simply purchase a new switch and put it in myself (probably against modern regs but I'm afraid that doesn't much bother me).   Le compteur is correctly switching to heures creuses at the designated time so the EDF signalling system is working correctly up to that point.

Can anyone confirm how that signalling is then passed to the automatic switching relay,   and of any other symptoms that would allow me to determine where (and with who!) the fault might lie?

Thanks.

[Cat]

I'm no techie Martin, but if it helps, we had exactly the same problem with our hot water switch, and mentioned it to our electrician as our installation was still fairly new.  He fixed it himself, so whichever path you chose I think you can probably rule out calling in the EDF.

 

[Anton Redman]

Your description corresponds with my understanding of how the system works. I cannot check anything at the moment, as current house does not have hueres creuse.

 

I would also use a continuity tester to check the neutral on 2 Amp fuse as these sometimes breakdown.

 

As the switch will latch in position during the heures cruese I would check that the feed back from the EDF box was live during HC. If the feed to the Contacteur Jour Nuit from the EDF box is live and the neutral from the CJN back to the 2amp fuse is intact then I believe the CJN is at fault. Three phase CJNs are 62,88 from BricoDepot.

 

If there is no feed then it sounds like an EDF fault.

[Chancer]

Martin

Check that the output from the 2amp disjoncteur is live, after that you can either wait until 22.27 to see if you have a live feed returning to the CJN or the best way is to "hot wire" the CJN input terminal direct from the 2 amp feed which should trigger the CJN if it is working correctly.

If that works OK I would suspect the EDF realy or the wiring to and from it, good luck.

P.S.

I am sure that I dont have to add that when I say "hot wire" I dont mean flashing a bare live wire to the terminal[:)] rather switch off the 2amp disjoncteur, make an insulated  link between the two units and switch back on again.

I remember when I was really young I tried testing a solenoid on my friends mum's washing machine by hot wiring it in the same way as I was used to testing my car electrical faults, the result was impressive and unforgettable!

[Maricopa]

When our HC/HP switchover of the boiler stopped working, I discovered that one of the relay contacts (under the cover at the bottom of the meter) was loose.  Two turns of a screwdriver and hey presto,back to working properly again.  It's these contacts that energise the off/auto/on breaker from the 2A supply.

[Martin963]

Thanks folks,   I'll have a probe-round-the-back session (probably tomorrow) and see what transpires.    Good to have confirmation that they system works roughly as I had envisaged.

Now where did I leave those insulating welly boots?

PS  I'm chortling about that dramatic test on a washing machine.   One of our engineers once tested a large audio-use capacitor in a rather odd way,  after which he was left with just an empty can (and I mean really empty) and quite a mess on the ceiling.   Luckily he wasn't bending over it at the time.

[Gyn_Paul]

2A feed goes to the meter.

Switched 2A comes back and powers the relay.

Neutral comes from the other side of the 2A disjoncteur directly to the relay.

So jumpering from the phase side of the 2A disjoncteur to the phase side of the relay connection should cause it to leap into life.

When I had the meter changed to HP/HC in the other house (some 10 years ago: very new to France) the EDF man (those where the days!) spent ages trying to explain to me with my  - then even more - rudimentary French how the meter worked, and it was quite some time before the penny dropped and I understood that there was no internal volts feed involved and that all the meter does is open and close a switch contact at the appropriate time.

I'd start by jumpering the feed to/from the meter to the CJN, then do a continuity test to/from the meter when it's HC time, Martin.

p

[Martin963]

Thanks for the further clarification,  I hadn't realised that the set up was   dist board  --->  meter switch ----> dist board but it makes sense. 

All I need now do is to incorporate that well-travelled energy meter you so kindly provided G_P and I can then worry about the nightly consumption of a relay!!

At least the meter is switching correctly when it comes to charging us money.    We've had two meters "go" here over nine years,   one stuck on HP and the other stuck on HC.    That and our  "neutre arraché" which caused me in the end to change insurance companies (when they fought tooth and nail over a €100 claim for damaged equipment).

But I think that story is in the archives here anyway.....

[Gyn_Paul]

Martin's gone very quiet.... you don't suppose he's blown himself (and his little BBC-avo-in-a-leather case) do you? [;-)]

p

[Martin963]

Non -  je suis toujours en vie.....

The 2A fuse in our case is on the return leg of the trip to le compteur;  this is "floating" at 79V at present (I assume that it's an induced emf) but I'm standing by to measure what is coming back from the meter in about 15 mins time!

[Chancer]

BANG! [6]

[Martin963]

...   and the full 230V wellie has now appeared on the signalling input of the boiler switch,   so I conclude that I need a new one along the lines of the one that Anton recommended from Bricodepot.

There was a very feeble buzz from the relay as the full voltage kicked in,   but not enough to throw the contacts.

I'm now going to ask the dumb question -  is there a technique for removing components off the backing rail in the distribution panel?   I seem to remember loosening a screw on the individual units when I had to replace a circuit breaker in the UK but can't see the equivalent here -  although I haven't examined it really closely yet.   I'm entirely confident about the wiring,   but the demontage.....?

There,  I'm not proud!

Actually the previous post gave me a slight frisson,   all those capitals and red ink!!

[Gyn_Paul]

With the modern, mono-phase items, there's usually a little plastic tab protruding from the bottom of the unit, with a space in it which will fit a mains tester screwdriver. It is spring-loaded and pulling on it (or levering it with the said screwdriver) releases a locking tooth which is holding the unit on the bottom of the rail. The top part is a fixed tooth.

Bonne Chance !

p

[Martin963]

Thanks,   I'll take a proper look with a good light this am.    I think that was how the UK one worked now you mention it - the screw was a fantasy on my part (?!) but I remember that once one had the technique it was very easy.

Our French system is 1990's 3 phase but I imagine it'll be similar.

[Chancer]

Martin

Just double check that all screw terminals are tight, especially the ones to the borne neutre (bus bar) it might just be that as the buzzing indicates continuity, so there is either a high resistance on the neutral return or the relay mechanism is broken or sticky.

For the latter case before laying out on a new one try giving it a measured wallop while it is buzzing[6]

[Martin963]

I'll try both tonight (I gave it a measured tap last night,   and have nothing to lose by upgrading to the "gentle persuader" as my FIL used to call his hammer (he was actually a very fine electronics engineer,  although more at home in the valve era).

And yes,   I can see a copper coloured latch-thingy below the switch with a slot in it.

[CeeJay]

Have read this thread with great interest, and other similar ones over the years and am now starting to worry that the system I have is not what might be deemed to be proper for heures creuse. I do not have a thingy in the fuse box controlling the time but have fitted a digital timer between the chauffe eau and the mains supply to click in at the appropriate times in order to gain benefit from the cheaper periods. Is this a correct way of doing things or am I missing something here?

[cooperlola]

Generally, Ceejay, on a modern panel with circuit breakers (as opposed to the old style fuses) the water heater has a three-way switch (which is what Martin is talking about.)  This has three positions - off and on, plus another which automatically turns the heater off during heures pleines and back on again during the creuses ones - and thus obviates the need for your own timer.  If you have an old-style fuse box, then the switch option is probably not available...  but those who dare to muck about with their own electrics probably know more!

[Martin963]

@ ceejay

There's nothing "wrong" from a practical point of view with what you've done (assuming it's a single phase supply to the chauffe eau) but I would be careful to keep an eye on the state of the timer - a lot of these things are not terribly robustly built and whilst fine for switching lights etc start to get into difficulties if used on something rated say at 3 kW and thus drawing 13A or so.   Even switches designed for this purpose can get burnt out contacts quite quickly.

I really would make sure that what you're using is well away from anything that could propagate a fire in the event of the worst happening - it's very unlikely but I would take no chances unless the switch is specifically designed for the job.

(Having seen a dishwasher after it caught fire in the small hours in our kitchen I've a healthy respect for that sort of thing noww!)

[Gyn_Paul]

[quote user="Martinwatkins"]I'll try both tonight (I gave it a measured tap last night,   and have nothing to lose by upgrading to the "gentle persuader" as my FIL used to call his hammer (he was actually a very fine electronics engineer,  although more at home in the valve era).

And yes,   I can see a copper coloured latch-thingy below the switch with a slot in it.

[/quote]

My first Station Engineer used to call one of those a 'manchester screwdriver' (we were in Liverpool at the time, of course).

Edit : This is my first posting using 'Opera' - what the hell have I done wrong ???

Probably something to do with the forum sofaware not being quite au fait with some browsers... All sorted out now [:)]

[Martin963]

Round here in Perigord resort to a hammer is known as doing something "a la Parisienne" I believe.

[Maricopa]

What's the latest?  Is it all now working correctly?  Was it the breaker in the end or just a case of tightening  the connections? 

Just curious[:D]

[Martin963]

Haven't got that far,   but as all the screws are well done up and the continuity to neutral seems OK I can only assume it's the actual relay in the timeswitch.

So I'll just do it manually until I can get to Bricodepot,   which is 30 miles from us and in these straightened financial circumstances of our debased coinage is something I'll put off until we need other things from the big bad city.

But thanks for asking!    I will let you know whether a replacement does the trick.

Talking of the £/€,   Simon Calder who is the travel editor for one of the big nationals was on the BBC this am and described British tourists to Europe as facing the equivalent of hyper inflation -  and I know what he means with prices up anyway and purchasing power of the £ down 15% since we were last here.

He was another ex BBC colleague and would challenge any new Studio Manager to a breakfast eating competition,   he was known as downing industrial sized breakfasts anyway.   He and I came to an honourable draw in the end after consuming vast quantities of fried items,  including black pudding.    We were both described as comfortable afterwards.

[Martin963]

Update -  new switch has been obtained and fitted,  now waiting for the magic hour of 22.25.    However,   I did retest the old switch by putting mains volts across the A1/A2 terminals and it didn't respond so I think the replacement is justified.

Will report back when the Heures Creuses begin.

[Jacqui Too]

[quote user="Martinwatkins"]
Will report back when the Heures Creuses begin.
[/quote]

And........

Come on Martin I waited up for your post [;-)]