Re: Manifold/TRV actuators - 24V or 240V?

[Richard Challis <richard@xxxxxxxxxxxxxxxxxx>]

Hello,

Bit of delay in replying to this one - sorry.

I went for 24v AC. I'm using 5 DIN mounted relay modules from Idratek.
The two pumps are controlled in a separate box with two 240v solid
state relays. The central heating boiler is controlled also in this
box via a normal relay. I use different colour tri-rated cable to
indicate voltage and AC or DC.

Blue / Brown - 240v
Orange - volt-free contacts (ie the device controlled supplies the
voltage - ie the boiler)
Purple - 12v DC
Dark Blue - 24v DC
White - 24v AC

I used isolated transformers to supply the voltage to the actuator
coils. I have 7 zones upstairs and 9 downstairs. These are supplied
via separate transformers and relay modules so that a failure in this
area will only affect half the house.

Hope this is useful and not too late :)

Cheers

Richard




On 5 November 2010 08:57, simon_haslam <simon_haslam@xxxxxxx> wrote:
> I'm nearly at the point of finishing off my CH installation and have
to s=
ort out the actuators for the 7 port manifold that will run my radiator
zon=
es.
>
> I will be controlling the zones using a HobbyBoards 1-wire 8 channel
I/O =
board (http://www.hobby-boards.com/catalog/product_info.php?cPath=3D24&prod=
ucts_id=3D1554) which has 8 relays on it, each rated at up to 60W
(0.25A@24=
0V).
>
> I can get both 24V and 240V actuators for my manifold. I was
originally g=
oing to use 24V ones as they would be low voltage within whatever
enclosure=
I find for the relay board. The 24V actuators are AC so I was planning to =
drive them from Maplin power supply (Maplin 1.5A L55BR http://www.maplin.co=
.uk/Module.aspx?ModuleNo=3D96964&OrderCode=3DL55BR).
>
> However I am now thinking I'll need at least one 240V relay (to
control t=
he boiler demand) so maybe I should have all the actuators as 240V too?
Tha=
t would be about =A333 cheaper (actuators + PSU), plus if a future owner
wa=
nted to use some other controls later (1-wire isn't very
plumber-friendly!)=
I suppose 240V is far more common and could be easily rewired. A 24V AC PS=
U would be another thing to go wrong too.
>
> Note: power consumption is about same - 24V supply uses about 4W when
idl=
e & according to spec the 24V actuators is 3VA whereas the 240V is
3.45VA. =
So for 7 valves open that's ~25W for 24V actuators and 24W for 240V ones.
>
> What do people think? Stick to 24V and know everything is low voltage
(an=
d no Part P concerns) or go for the much more common 240V?
>
>
> Simon (procrastinating again!)
> PS. I've posted this on Navitron too and will report back any
response.
>
>
>
> ------------------------------------
>
>
> Yahoo! Groups Links
>
>
>
>


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