electrical Regs on connection before consumer unit....

[guydewdney]

Well - thats the problem - The meter tail to the consumer unit goes via an 'eton' block (bakelite thing) Unless each and every wire has a fuse / protection on it - then it is unfused - and thus dodgy. The wire from meter to eton and so on is all big fat (25mm? 16mm?) double insulated stuff. I need to tap into this wire for the RPR to power up the heater(s)

meter----RPRs------eton block----consumer unit
              I              I
        500w loads     wheel

The wheel genny / inverter etc has a full (mini) three phase consumer unit - RCD, 16A (C rated)fuse etc etc.

[northern installer]

Guy,when you say 'tap in' do you mean a series connection of the main tails through the sensing relay?

[guydewdney]

A close up of that bit

meter===T=====CT clamp===blah (wheel / etc)
              I          I
            relay....Rev power detection
              I
           Heater

key:-
=     double insulated 16mm or 25mmm meter tail
T     Tapping (eton block?)
I      cable - undetermined
...    thinner cable - ?low voltage? just to power relay

[tony.]

sorry but i need a circuit diagram.

ok the power relay is just like a normal relay according to the pdf.

so  its coil will need protection from a 2 amp mcb or something small.
the eaton blocks are called henley blocks and are used to join double insulated tails together.

ideally, we would like some kind of large consumer unit, to act as a housing with a double pole main switch fed from your wheel consumer unit, so it will already be rcd 30ma protected,  a 2amp breaker for feeding the coils of the relays and a 6 amp breaker for protection for the loads( not sure about discrimination ) and  2.5mm twin and earth out to each of the loads from the power relays

the diagram would help

tony

[northern installer]

Still not enough info for me Guy;are the relays measuring VOLTAGE in which case a parallel connected thin wire with appropriate current protection will do,or CURRENT in which case a series connection carries all the load,or by current transformer,slipped over the cable,output in milliamps?
If,as I suspect, its voltage,wire a new small consumer unit from the eaton block and use a small mcb with 1.5 twin/earth cable to the sensor............

[guydewdney]

The relays measure voltage AND current (via a CT) - and compare the two, with a bit of magic - they work out the current direction.

So - I need three+ consumer units - don't I...?

[tony.]

guy,

http://www.tlc-direct.co.uk/Products/MK5621.html

is a 21 way board, the power relays look like they may be 4 modules wide, so thats 12.

add the coil mcb, 3 for the other mcb for load circuits and 2 for the main switch and thats 18 ways plus some spares!!

EDIT forgot it was a 3 phase board, so add a nother 2 for the 3phase main switch that 3phases and neutral, so that leaves 1 spare.
i dont see anything wrong in using a single phase enclosure for a 3 phase bit of kit, especially as the loads are so small( current wise, not cost/savings wise).
i would use tri rated cable to link all the equipment together, ie make your own panel wiring


TONY

[daftlad]

guy,

http://www.tlc-direct.co.uk/Products/MK5621.html

is a 21 way board, the power relays look like they may be 4 modules wide, so thats 12.

add the coil mcb, 3 for the other mcb for load circuits and 2 for the main switch and thats 18 ways plus some spares!!

EDIT forgot it was a 3 phase board, so add a nother 2 for the 3phase main switch that 3phases and neutral, so that leaves 1 spare.
i dont see anything wrong in using a single phase enclosure for a 3 phase bit of kit, especially as the loads are so small( current wise, not cost/savings wise).
i would use tri rated cable to link all the equipment together, ie make your own panel wiring


TONY

Or to give yourself more space you could put a bit of din rail in an adaptable box and put all of your relays etc on that, remember you will need access to any RCD's or MCB's so they would have to go into something else. Or get box with space for breakers and space for relays. (I know I havn't described this well, basically like what Tony suggests but more space in the box would be easier.)
I will try and post information on the French thing soon.
ta ta

[tony.]

a consumer unit would be better as it has the aperture for fitting mcb size accessories,
it also has a clear lid that you can see leds etc and alter pots.
after all its only going to have 2.5mm2 wiring coming from it so it doesnt need a lot of room to dress cables etc.
they have handy knockouts for entry points,  you could get 2 and bush 2 of them together if you want.
it will be cheaper than buying a bit of din rail and a decent enclosure, i doubt you will get a decent enclosure for £17
tony

[northern installer]

The french thing? pah! I dont think johnny foreigner has invented anything we dont already have! over the years I have designed and built several panels to control mains loading,or,more accurately to shed mains loading before it rises to a troublesome level;one such animal was interlocked to several machines,delaying a point in their automatic  cycle if the overall factory load was running into the penalty sector,shedding load as necessary ;a simpler system was made for an industrial customer who was overloading the incoming main,load shedding the heating during motor run up periods got around that problem;its all as simple (current sensors and contactors) or as complex (plc and multiple sensing)as you want it to be!   Guy,you want this system in reverse ?

[daftlad]

The french thing? pah! I dont think johnny foreigner has invented anything we dont already have! over the years I have designed and built several panels to control mains loading,or,more accurately to shed mains loading before it rises to a troublesome level;one such animal was interlocked to several machines,delaying a point in their automatic  cycle if the overall factory load was running into the penalty sector,shedding load as necessary ;a simpler system was made for an industrial customer who was overloading the incoming main,load shedding the heating during motor run up periods got around that problem;its all as simple (current sensors and contactors) or as complex (plc and multiple sensing)as you want it to be!   Guy,you want this system in reverse ?

As you say I dont think johnny foreigner has invented anything we dont already have! You are right, the difference is that the French use it in domestic installations because they have smaller supplies to the houses, it allows them to load shed heating etc.
Here is a picture out of a french electrical installation book.
ta ta

[crispy]

Here's some more information on these 'delesteurs'

http://www.iufmrese.cict.fr/catalogue/2003/delestage/Documents_ressources.pdf

It seems that they can manage up to 3 loads via separate contactors.

Shame I can't figure out under which conditions they actually control the loads though... Back to french school for me...

[guydewdney]

Yes - NI - I do - but with simple CT clamps wired to a contactor (as in the 'french Thing') - it doesnt know the current direction - essential in my case!

It is perfectly possible that we can have the oven (3 or 4kw) on, microwave (1.5kw) and all four rings of the induction hob on (7kw) - plus toaster, pooters etc and be pulling a hell of a current. Before Martin has a heart attack - we are feeding anything up to 12 hard working adults.... At this time - there is a huge incoming current - and at 3am - theres 3 off kw going out... so you need to determine which way its going (I did think of using the 'export' LED on the main meter)....

I must go and play with some software a nice member sent me for a PLC system.

[daftlad]

Guy
I think you may be along the right lines with the reverse power relay, I now know what you are trying to do (I think).
I am guessing it uses some kind of shunt to detect current? do you have any idea what sort?
Or you could use the french thing, but you would need some sort of disconnect based on the export LED which would stop the power being shed to the heaters. I will have a bit of a think about the french thing, I will try to figure out if it can be made to work, I am thinking 2 current clamps in series, one on the generator and one on the house, the currents could be made to cancel each other out, and the difference could be measured and if high enough dumped into a heater?
Or I may be talking rubbish. 
But like I said, I recon the reverse power relay could work, can you try and find some more information on them, including the current sensing.
ta ta

[guydewdney]

Daftlad - in a way - that is what I had been thinking.

does a CT clamp have a 'way round'?

would two CT clamps wired in series, but with one the opposite way to the next on the senseD wire, cancel each other out - or not? I have looked - but cant find an answer.

If they do - then that make life easy - two CT clamps - one on gen - one on Cons Unit - wired anti-phase - and the resultant being fed to a low trigger type relay (which funnily enough - I have...) would be a cheap and easy way of doing this.... And would get round a lot of problematic connections.