Re: Urgent help required: Star vs Daisy chain wiring for aircon control

["christopher purves" <CHRIS_PURVES@xxxxxxx>]

I wish I could find out - I am digging in their docs.


Chris


>From: "Frank Mc Alinden" <frankmc@xxxxxxx>
>Reply-To: ukha_d@xxxxxxx
>To: <ukha_d@xxxxxxx>
>Subject: Re: [ukha_d] Urgent help required: Star vs Daisy chain wiring
for
>aircon control am I screwed
>Date: Wed, 28 Sep 2005 22:12:52 +1000
>
>Hi Chris
>             Can you confirm  that the communication is rs 485
???....If so
>then it  should be ok to star or daisy chain ,although rs485 specs
state
>daisy chaining......
>
>Frank
>----- Original Message -----
>From: "christopher purves" <CHRIS_PURVES@xxxxxxx>
>To: <ukha_d@xxxxxxx>
>Sent: Wednesday, September 28, 2005 10:07 PM
>Subject: [ukha_d] Urgent help required: Star vs Daisy chain wiring for
>aircon control am I screwed
>
>
> > OK the story so far:
> >
> > We have had a whole house Daikin air conditioning system
installed(hot
>and
> > cold). 8 indoor units connected to 2 external units (4 internals
to each
> > external). We opted for a touchscreen to control this setup as it
could
> > provide timing to turn units on and off along with themostats and
so
>forth
> > so it behaved much like a convetional heating system.
> >
> > Each unit in the chain (including external units and the
touchscreen)
>has
> > an
> > f1 and f2 signal connection.
> >
> > Originally Daikin told our installer to wire as a 'star' back to
the
> > touchscreen location which required a single 2 core cable to each
indoor
> > and
> > outdoor unit back to the touchscreen which of course they did. In
effect
> > join all f1's together and all f2's together and attach to f1 and
f2 on
> > the
> > trouchscreen.
> >
> > However when speaking to Daikin today, Daikin are claiming the
internal
> > units must be wired in a daisy chain (one to the next). 4 units
daisy
> > chained into 1 external unit (so 2 setups like that) and then
both
> > external
> > units back to the touchscreen (again f1's to f1's, f2's to f2's).
>Clearly
> > the existing wiring does not support this method as there are not
enough
> > cores but, I cannot for the life of me understand why a star and
a daisy
> > chain should be any differrent ? Electrically it seems the
connections
>are
> > the same.
> >
> > I would also point out that each unit has an address settable by
a four
> > input dip switch.
> >
> > Can we just ignore their comments and wire it a as a star ?
> >
> > Certainly CBUS can be wired as either.
> >
> > Anyone ?
> >
> > Help greatly appreciated. The installer and I are tempted just to
try it
> > but
> > given the cost of the equipment we are a little nervous. On the
>otherhand
> > given that all the decoration is now finished it will cost us
thousands
>to
> > rewire.
> >
> > Ta
> > Chris
> >
> >
> >
> >
> >
> >
> > Yahoo! Groups Links
> >
> >
> >
> >
> >
> >
>
>
>
>
>
>Yahoo! Groups Links
>
>
>
>
>
>