Manifold/TRV actuators - 24V or 240V?

["simon_haslam" <simon_haslam@xxxxxxxxxxx>]

I'm nearly at the point of finishing off my CH installation and have
to sor=
t out the actuators for the 7 port manifold that will run my radiator
zones=
.

I will be controlling the zones using a HobbyBoards 1-wire 8 channel I/O
bo=
ard (http://www.hobby-boards.com/catalog/product_info.php?cPath=3D24&produc=
ts_id=3D1554) which has 8 relays on it, each rated at up to 60W
(0.25A@240V=
).

I can get both 24V and 240V actuators for my manifold. I was originally
goi=
ng 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 dr=
ive them from Maplin power supply (Maplin 1.5A L55BR http://www.maplin.co.u=
k/Module.aspx?ModuleNo=3D96964&OrderCode=3DL55BR).

However I am now thinking I'll need at least one 240V relay (to control
the=
boiler demand) so maybe I should have all the actuators as 240V too? That =
would be about =A333 cheaper (actuators + PSU), plus if a future owner
want=
ed 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 PSU =
would be another thing to go wrong too.

Note: power consumption is about same - 24V supply uses about 4W when idle
=
& 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 (and
=
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.



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