Hi,

I have a relatively complex setup and was wondering if anyone had any
views on the best way to wire it all up... Also, any advice on whether
a wiring centre is a good idea as they seem to be very expensive given
what they appear to be....

Setup is....
-----------------
3 x radiator heating zones timed centrally and operated by 2 port
motorised valves
1 x towel rail heating zone timed centrally and operated by 2 port
motorised valves
1 x hot water tank heating timed centrally and operated by 2 port
motorised valves
1 x secondary hot water loop timed centrally.
2 x underfloor heating zones with 2 wire actuators, pump, manifold,
controlled by a prog room stat
zone 1 has 1 actuator
zone 2 has 5 actuators

All ideas appreciated.

thanks

Lee.

On Mon, 10 Aug 2009 04:01:11 -0700 (PDT), Lee Nowell wrote:

Also, any advice on whether a wiring centre is a good idea as they seem
to be very expensive given what they appear to be....

A normal wiring center won't cope with that number of zones.

For the system here (just four zones 2 x HW, 2 x CH, with shared
circulators for the two HW zones and two CH zones). I bought a small
(three row) DIN rail enclosure and lots of terminals. All the wires
from the valves, thermostats, timers, etc come back to that box so
and config changes are just jumper changes in the box not house
rewire jobs.

The logic for the pump, boiler and pump over run control is done with
half a dozen DIN rail mount minature relays. If I was doing it again
I'd find a large enough PLC, even easier to adjust the logic. I'd
retain the normal programmers as they have nice simple buttons and
displays that ordinary people can understand.

--
Cheers
Dave.

On Aug 10, 12:27*pm, "Dave Liquorice"
wrote:
On Mon, 10 Aug 2009 04:01:11 -0700 (PDT), Lee Nowell wrote:
Also, any advice on whether a wiring centre is a good idea as they seem
to be very expensive given what they appear to be....

A normal wiring center won't cope with that number of zones.

For the system here (just four zones 2 x HW, 2 x CH, with shared
circulators for the two HW zones and two CH zones). I bought a small
(three row) DIN rail enclosure and lots of terminals. All the wires
from the valves, thermostats, timers, etc come back to that box so
and config changes are just jumper changes in the box not house
rewire jobs.

The logic for the pump, boiler and pump over run control is done with
half a dozen DIN rail mount minature relays. If I was doing it again
I'd find a large enough PLC, even easier to adjust the logic. I'd
retain the normal programmers as they have nice simple buttons and
displays that ordinary people can understand.

--
Cheers
Dave.

Hi Dave,

Thanks for your reply. I don't suppose you have a wiring diagram do
you or a link to a suitable PLC?

The guy I bought the timers etc. from recommended this...

http://randall.danfoss.com/Product/0...U17433646.html

But I couldn't see how it would support what I have.

thanks

Lee.

In article
, Lee
Nowell writes
Hi,

I have a relatively complex setup and was wondering if anyone had any
views on the best way to wire it all up... Also, any advice on whether
a wiring centre is a good idea as they seem to be very expensive given
what they appear to be....

Setup is....
-----------------
3 x radiator heating zones timed centrally and operated by 2 port
motorised valves
1 x towel rail heating zone timed centrally and operated by 2 port
motorised valves
1 x hot water tank heating timed centrally and operated by 2 port
motorised valves
1 x secondary hot water loop timed centrally.
2 x underfloor heating zones with 2 wire actuators, pump, manifold,
controlled by a prog room stat
zone 1 has 1 actuator
zone 2 has 5 actuators

All ideas appreciated.

When I set up my system I did it with 9 zones (1 per room) but was
frustrated with the lack of multizone controls available at a reasonable
(or unreasonable) price.

In the end I have grouped rooms into 3 zones and used Honeywell
programmable stats to control the zones with TRVs in rooms not currently
directly stat controlled. The system is not without its problems however
as the demand from the stats is not synchronized[1], meaning that one
zone can call for heat and be satisfied just in time for another zone to
call for heat. The staggering of the zones can cause repeated light load
firings of the boiler which are inefficient and wasteful[2].

Your life will be made a lot easier if you have some kind of thermal
store on the heating side of the system, that way if one of your small
zones kicks in it doesn't need to fire the boiler to get heat. The last
thing you want is your boiler (which I assume is large) to be short
cycling repeatedly to satisfy the demand of a towel radiator. If you do
this, you don't need to synchronise your controls meaning you could
break the system down into smaller and more manageable blocks. You could
use a PLC to control those sub-blocks but I don't know of a controller
that will do the job as a whole.

If you don't have the hot water linked to your store then you can still
have the heating side flow at a temperature that suits best efficiency
for a condensing boiler.

I think your system is too complex for a single wiring centre to handle,
I would wire all your controls back to a single point and grow your own
wiring centre using a large shallow electrical installation panel filled
with DIN rails and rail mounted terminals, leaving plenty of space for
other DIN rail goodies to be added at a later date. Document the system
very well.

[1] Up to 4 Honeywell wireless programmable stats can be synchronised in
one of their moderate systems but there was I reason I didn't like it. I
think it was an insistence that you use RF controlled radiator valves to
control the heat.
[2] Made worse by Honeywell's (compulsory) proportional control system
which forces the boiler to be cycle at least 3 times an hour when the
temperature is in the proportional zone.
--
fred
BBC3, ITV2/3/4, channels going to the DOGs

Thanks very much for the reply.

The trouble I have is that I am not confident enough to grow one from
scratch. Whilst I think I understand the basics and logic, the wiring
bit (e.g. use of PLC/ relays) is a bit beyond my comfort zone...

Also, from what I can see, I have an additional problem to yours in
that I need to run the UFH with seperate pump and actuators in
addition to all the zones.

Maybe I could split the problem into 2
- UFH
- Non-UFH

and wire the demand from each in parallel to the boiler? Not sure
whether that resolves the relay problem though - I'm not sure why I
need them at all to be honest...

thanks
Lee.

In article
, Lee
Nowell writes
Thanks very much for the reply.

The trouble I have is that I am not confident enough to grow one from
scratch. Whilst I think I understand the basics and logic, the wiring
bit (e.g. use of PLC/ relays) is a bit beyond my comfort zone...

Also, from what I can see, I have an additional problem to yours in
that I need to run the UFH with seperate pump and actuators in
addition to all the zones.

Maybe I could split the problem into 2
- UFH
- Non-UFH

and wire the demand from each in parallel to the boiler? Not sure
whether that resolves the relay problem though - I'm not sure why I
need them at all to be honest...

You'd might be surprised at how simple the wiring can be.

Yes, you can separate that UF and conventional heating, that would be a
sensible place for a break but unless you use a truly synchronised
controller for the 3 conventional zones you are likely to run into short
cycling problems which may not be obvious but will stress the boiler
unnecessarily.

As I said, you could make this a lot easier with a bit of thermal
storage in the heating loop but it sounds like you have it already built
and aren't keen for that kind of change.

Relays can be a handy way to combine demands that need to be otherwise
isolated eg. in your case, where you have a pump for UFH and one for
conventional, using relays would let you combine those 2 demands to call
for heat at the boiler without switching on the pump on the other
circuit at the same time. Shout if you want a circuit.

Have you had a look at the uk.d-i-y heating wiki?
http://wiki.diyfaq.org.uk/index.php?...tegory:Heating
--
fred
BBC3, ITV2/3/4, channels going to the DOGs

On 12 Aug, 17:13, fred wrote:
In article
, Lee
Nowell writes



Thanks very much for the reply.

The trouble I have is that I am not confident enough to grow one from
scratch. *Whilst I think I understand the basics and logic, the wiring
bit (e.g. use of PLC/ relays) is a bit beyond my comfort zone...

Also, from what I can see, I have an additional problem to yours in
that I need to run the UFH with seperate pump and actuators in
addition to all the zones.

Maybe I could split the problem into 2
- UFH
- Non-UFH

and wire the demand from each in parallel to the boiler? *Not sure
whether that resolves the relay problem though - I'm not sure why I
need them at all to be honest...

You'd might be surprised at how simple the wiring can be.

Yes, you can separate that UF and conventional heating, that would be a
sensible place for a break but unless you use a truly synchronised
controller for the 3 conventional zones you are likely to run into short
cycling problems which may not be obvious but will stress the boiler
unnecessarily.

As I said, you could make this a lot easier with a bit of thermal
storage in the heating loop but it sounds like you have it already built
and aren't keen for that kind of change.

Relays can be a handy way to combine demands that need to be otherwise
isolated eg. in your case, where you have a pump for UFH and one for
conventional, using relays would let you combine those 2 demands to call
for heat at the boiler without switching on the pump on the other
circuit at the same time. Shout if you want a circuit.

Have you had a look at the uk.d-i-y heating wiki?http://wiki.diyfaq.org.uk/index.php?...tegory:Heating
--
fred
BBC3, ITV2/3/4, channels going to the DOGs- Hide quoted text -

- Show quoted text -

Thanks for the reply. A circuit diagram would be very useful -
thanks.

I had a further thought and was wondering if this would work????

Zone 1 – Under floor heating with 1 actuator – controlled by prog room
stat
-----------------------------------------------------------------------------------------------------------
Connect room stat demand to actuator, UFH motorised valve and UFH pump
in parallel

Zone 2 – Under floor heating with 5 actuators – controlled by prog
room stat
-------------------------------------------------------------------------------------------------------------
As for Zone 1 but wiring all 5 actuators in parallel with connection
to UFH pump in parallel with Zone 1


Timed secondary return pump
---------------------------------------------
Wired to the on/ off terminals on the timer

Remaining 5 zones – controlled by timers
------------------------------------------------------------
Connect the on/ off terminals for the zone to motorised valve


Connect the micro switches from all motorised valves together in
parallel and to the demand on the boilers

Finally, we have 2 boilers. Can they be wired together in parallel or
do we need any relay etc.?

Thanks again for all your help.

Lee.

In article
, Lee
Nowell writes

Connect the micro switches from all motorised valves together in
parallel and to the demand on the boilers

Finally, we have 2 boilers. Can they be wired together in parallel or
do we need any relay etc.?

Thanks again for all your help.

Lee.

You can wire demands in parallel in a simple system but where you have
separate pipe circuits with eg separate pumps then you have to find a
way of combining the demands (to feed the boiler 'call for heat') while
keeping the pumps separate (or you will turn on the pump for a circuit
that is meant to be off). This can be done with relays.

I've uploaded a couple of sketches which give the basics of how this is
done: http://i26.tinypic.com/2yzejko.jpg (first sketch).

Secondly, it wouldn't be that clever to run 2 boilers to service a
demand from a single small zone. To overcome this problem you can use
relays to create a demand to the second boiler only when a number of
conditions become active ie when condition (or demand) 1 AND condition
(or demand) 2 are met. I've shown a basic example of this in the second
sketch. Another option would be to only fire the second boiler when
there is a certain level of demand AND the temperature outside is lower
than a certain level, ie. when full power is really needed.

A clever 2 boiler design would also have provision for swapping the
control of the boilers round so that they aged at the same rate and an
option to remove a faulty boiler from the circuit.

Some manufacturers have helpful notes on the design of 2 boiler sytems,
here's a link to info from Keston which is for their pre-fabricated rigs
but the information should read across to other designs too:
http://www.keston.co.uk/multi-rig.html
http://www.keston.co.uk/downloads/manuals/rigcntrl.pdf

Or google for "dual boiler" +heating +system +design ( -coffee -espresso
)
--
fred
BBC3, ITV2/3/4, channels going to the DOGs