On Mon, 20 Sep 2004 05:43:55 -0700, JE wrote:
So basically just to get things clear in my mind
1) The Cable A Earth (green and yellow) isnt being used as earth, but
as a live cable to supply terminal 3 (from god knows where)?
Yes. Better put as terminal 3 supplies the HW demand signal to the G&Y core
of cable A (which goes TO god knows where).
2) The join between Cable A Neutral (blue) -Cable C Live (brown)
needs to maintained and permanently connected with connector strip
within the new C27 ?
Yes.
Best practice is not to use the C27 back plate as a mini
wiring centre. A wiring centre can be purpose bought or
easily made using a single or double patress with a choc strip inside.
I suspect there may also be a wiring centre or junction box elsewhere.
You actually only need 4 wires + Earth to wire the time switch, L & N
and one core from 3 for HW demand and one from 4 for CH demand.
3) Cable D must be the mains supply, (as it's the only cable with all
three wires going to the corresponding EP2000 Earth, Line and Neutral
terminals. Any idea on what the other 3 cables could be used for by
looking at the picture? (note there is also a fused single switch for
the controller to the right of the EP2000, but I assume this is just
in series and supplies the power to the controller and therefore
doesnt supply any other cables in the controller)
I'm sure the switch (containing 13A fuse should be 3A) runs one of
cable B or D.
You cant say if Cable B or D is the supply since both their cores are
effectivly connected to LN&E. The other cable of B&D likely goes
to the boiler to provide a permanent power supply.
If 1 is correct, then Id never had thought that people would use spare
wires without at least putting the correct colured insulating tape
over them.
You have a lot to learn about the depth, breadth and creativity
of corner cutting...
Good idea on the 6 core - if u do this thing regularly.
Thanks for the FAQ link too - I now know what the 10/16 EP2000 switch
is for.
Yes the 10/16 is very arcane. 8-)
A wild guess based on what I see form the photos plus experience:
The system is operated in '10' or gravity mode there is just a hint that
the photo shows the EP2000 in 10 mode. You can't have HW off
when the CH on. There is a zone valve for the CH.
The boiler is a modern unit requiring a permanent supply. The earth wire
was probably reassigned when the boiler was replaced. It might even go all
the way to the boiler as is. Somewhere along cable A between the timer and
the boiler the wall thermostat joins brown to blue.
Cable B&D are mains, one is supply likely D, and the other goes to the
boiler as a permanent supply.
Cable A takes CH and HW demand out on brown and G&Y. The blue cable is
likely the return from a wall thermostat. The G&Y operates the boiler
demand terminal. Either the boiler works the pump or the G&Y also does
that.
Cable C likely goes to the CH zone valve to put the radiators on. The
micro switch in the zone valve (cable cores orange and grey) is not used.
Boiler is a Potterton Suprima or Baxi Solo? The EP2000 is an older bit of
kit which predates the boiler?
--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at
www.diyfaq.org.uk
Gas fitting FAQ
http://www.makewrite.demon.co.uk/GasFitting.html
Sealed CH FAQ
http://www.makewrite.demon.co.uk/SealedCH.html