User Manual

14
Function
description
Description of functions
Synchronization of clock time
The clock time can be set on any of the Synco 700
controllers (RMH, RMU) and is synchronized through-
out the system.
The clock time can also be displayed on the room
thermostats (RDG).
Time switch
Geographical zone
The time switch master – in this case the central
control unit (RMB) – forwards the Comfort, Precomfort
and Economy modes to all room thermostats (RDG)
in its geographical zone. This means that all room
thermostats (RDG) operate according to the time
switch of the time switch master.
With the room thermostats (RDG), there is no time
switch slave zone available. Here, the apartment
address of the geographical zone must be identical
with that of the time switch master. With the room
thermostats (RDG), the subzone address is always 1
and cannot be changed.
Holidays / special days
Geographical zone
With the room thermostats (RDG), it is not possible to
set a holidays / special day zone. This information is
distributed in the geographical zone via the time
program.
Outside temperature
Outside temperature zone
Primary air handling (RMU, basic type P) distributes
the outside temperature in outside temperature zone
1. All devices in outside temperature zone 1 operate
with the same outside temperature.
With the room thermostats (RDG), the outside tem-
perature zone cannot be set; it is always 1. If the
room thermostats (RDG) shall acquire the outside
temperature, it must be distributed in outside tem-
perature zone 1.
VAV control
Geographical zone
The VAV controller (GDB) opens or closes the VAV
damper to such an extent that the volumetric air
volume setpoint is maintained. The volumetric air
volume setpoint is given by the room thermostat
(RDG) via KNX bus according to the heat resp. refrig-
eration demand.
Optimization of energy usage
Heat distribution zone
When primary air handling calls for heat from the air
heating coil, the air handling controller (RMU, basic
type P) forwards a heat request to heat generation
(RMH) via heat distribution zone 1.
Heat generation (RMH) provides heat only when at
least one of the consumers in the system calls for it
(demand-dependent control).
Refrigeration distribution zone
When primary air handling calls for cooling from the
air cooling coil, the air handling controller (RMU, basic
type P) forwards a refrigeration request to refrigera-
tion generation (RMU, basic type C) via refrigeration
distribution zone 1.
Refrigeration generation (RMU, basic type C) provides
chilled water only when at least one of the consumers
in the system calls for it (demand-dependent control).
Air distribution zone
If heating is required, the room thermostat (RDG)
sends a request for warm air to primary air handling
(RMU, basic type P). If cooling is required, the room
thermostat (RDG) sends a request for cold air to
primary air handling (RMU, basic type P).
Based on the request for warm or cold air, primary air
handling (RMU, basic type P) adjusts the supply air
temperature setpoint and controls the air heating or air
cooling coil in a way that the supply air temperature
setpoint is maintained.
Primary air handling (RMU, basic type P) sends the
current supply air temperature in the air distribution
zone to the room thermostats (RDG). These compare
the current room temperature with the supply air
temperature and decide whether the air shall provide
heating or cooling.
The VAV controller (GDB) for the room supply air
resp. room extract air sends its damper position (cur-
rent value) to the primary air handling controller
(RMU). The pressure setpoint of the supply air pres-
sure resp. extract air pressure control are shifted
accordingly. This function guarantees an optimal and
energy efficient plant operation.
Release of reheater
Air distribution zone
Primary air handling (RMU, basic type P) sends the
fan status to the room thermostat (RDG). The room
thermostat (RDG) releases the electric reheater only
when the supply air fan is running and when the VAV
damper has been driven to its minimum position. The
room thermostat (RDG) sends the electric reheater’s
operational information to primary air handling (RMU,
basic type P). When the reheater shuts down, the
supply air fan continues to run for a certain period of
time to cool down the reheater.
Note: The electric reheater must be protected in a way
that fire cannot break out, even if communication fails.
Fire alarm off / smoke extraction
Geographical zone
The central control unit (RMB) forwards the “Fire
alarm off” or “Smoke extraction” signal to the room
thermostats (RD
G). During “Fire alarm off”, the room
thermostats (RDG) drive the air dampers to the fully
closed position and, during “Smoke extraction”, to the
fully open position.
Air distribution zone
During “Fire alarm off” or “Smoke extraction”, the room
thermostats (RDG) forward the signal to primary air
handling (RMU, basic type P). In the event of fire, the
fans are switched off. If smoke extraction is called for,
the supply and/or extract air fans are switched on.
Note: To ensure that primary air handling (RMU, basic
type P) also receives the “Fire alarm off” and “Smoke
extraction” signals when communication fails, the
signals must also be fed to this controller, in addition
to the central control unit (RMB).