User Manual

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Siemens HVAC central apartment unit with consumption data acquisition QAX903 CE1N2741en
Building Technologies 2016-01-30
1 cooling enable contact can be assigned to each room to activate a cooling unit
(e.g. split unit).
Enabling can occur via the local relay contact of the central apartment unit, the
relay contacts on the heating circuit controllers RRV912 / RRV918, the multi-
controller RRV934, or via S-mode.
Int
egration of the ZENNiO Interface (S-mode TP) allows the central apartment unit
to control the operating mode, setpoint and enabling for the air conditioning (e.g.
split unit) per room. Heating and cooling mode for the air conditioning unit are
supported.
Room temperature control is autonomously taken over by the air conditioning unit.
Sp
ecific functions for monitoring and operating function
The window contacts are used for the window ventilation function. As soon as a
window monitored by a window contact is opened, the heating circuits for the re-
spective room stop opening their valves, even if the room temperature drops for
short periods. The room temperature level drops to protection mode after a set
period expires, until the window is closed again. "Normal" control is resumed after
the window is closed.
An open window can also influence operation of a ventilation plant or air condi-
tioner.
This prevents unnecessary heat losses during the airing phase and subsequent
overheating.
Exhaust hood operation can also be influenced by monitoring window contacts.
The c
entral apartment unit receives measured values for outside air pressure and
air pressure from the meteo sensor or via KNX TP.
The current measured values for outside air pressure and outside temperature as
well as the air pressure trend can be displayed in the quiescent picture. The quies-
cent picture displays changes in outside air pressure over the last few hours in the
form of an arrow.
Moreover, the weather trend (sunny, varying, bad) is determined based on a
change in air pressure and absolute pressure, and is displayed in the quiescent
picture.
The curve for outside air temperature and outside air pressure over the last 24 hours
can be queried via 2 info pages.
Whether at home or on the go – the HomeControl app, in combination with the
OZW772 web server, provides intuitive and simple control of your heating, air
conditioning and ventilation system, as well as light and shading, from anywhere.
Air conditioning unit
via ZENNiO module
Window contacts
Weather station
Smart phone app
Cooling enable contact