Switching on and off
4
15
We reserve the right to make any changes due to technical modifications.
Installation and service instructions RC20 room controller • Issue 08/2006
4.3
Operating tips
Devices on the EMS bus
Only one device can be the master on the EMS bus. If a
programming unit (e.g. RC30/RC35) is installed in a heating
system, this assumes the master function. The RC20 room
controller must be installed as a remote control unit with the
relevant heating circuit address (see section 5.4 "Address
1)
",
page 19).
Frost protection
–
If the RC20 room controller is installed as a remote control unit,
the frost protection function can be set on the programming unit
(e.g. RC30/RC35).
–
When the RC20 is the sole programming unit
1)
, the heating
system operates with the room temperatures specified for day
and night mode. Switch-off is not possible in night mode
(temperature reduction only).
Important: If the room temperatures have been set below
10 °C, there is no absolute frost protection because, for
example, pipes routed through external walls could freeze up,
even though the temperature in the reference room is
substantially higher than 5 °C due to external heat sources.
Pump kick
2)
In all operating modes all pumps are switched on and then off again
for 10 seconds every Wednesday at 12 noon to prevent pump
damage. The mixers are then switched for 10 seconds to "OPEN"
and then to "CLOSED". All pumps and mixers then return to normal
operation.
The pump kick is not carried out if the room controller has been
installed as a remote control unit for a RC30/RC35 programming
unit.
CAUTION!
SYSTEM DAMAGE
caused by frost if the RC20 is the sole programming unit.
z
Set the room temperatures higher than 10 °C.
1)
This always applies to operation using boilers with UBA 1.5.x.
2)
Not possible for boilers with UBA 1.5.
