Permissible ambient temperature
– during operation
0 to +40 °C
Installation in living
spaces or boiler rooms
(standard ambient con-
ditions)
– during storage and transportation
−20 to +65 °C
Rated relay output breaking capacity
sÖ
Heating circuit pump
or
Primary pump, cylinder loading sys-
tem
or
Circulation pump, flue gas/water heat
exchanger
or
Switching output
4(2) A, 230 V~
sA
Circulation pump for cylinder heat-
ing
4(2) A, 230 V~
sK
DHW circulation pump
4(2) A, 230 V~
sL
Shunt pump/boiler circuit pump
4(2) A, 230 V~
gÖ
Central fault message facility
4(2) A, 230 V~
gS
Mixer motor, extension kit, mixer
Motor, 3-way mixing valve, cylinder
loading system
0.2 (0.1) A, 230 V~
Total
max. 6 A, 230 V~
fA
Burner
6(3) A, 230 V~
Delivered condition
■ Control with integral programming unit
■ Outside temperature sensor
■ Cylinder temperature sensor
■ Bag with technical documentation
Heating system with DHW cylinder
Order separately:
■ Circulation pump with check valve for regulating the cylinder tem-
perature
or
■ Vitotrans 222 cylinder loading system with mixer assembly
Heating system with heating circuit with mixer
A mixer extension kit (accessories) is required for each heating circuit
with mixer.
Communication
The LON communication module (accessories) is required for com-
munication with other control units.
9.8 Vitotronic 300-K, type MW1B, part no. 7498 906
Specification
Construction
The control unit comprises a standard unit, electronic modules and a
programming unit.
Standard unit:
■ ON/OFF switch
■ Emissions test switch
■ Optolink laptop interface
■ Fuse/MCB
■ Operating and fault display
■ Plug connection chamber:
– Connection of external equipment via system plug
– Connection of three-phase consumers via additional contactors
Programming unit
■ Straight forward operation:
– Plain text display with graphic ability
– Large font and black/white depiction for good contrast
– Context-sensitive help
■ Operating keys:
– Navigation
– Confirmation
– Help and additional information
– Extended menu
■ Settings:
– Boiler sequence
– Set room temperatures
– DHW temperature
– Operating program
– Time programs for central heating, DHW heating and DHW circu-
lation pump
– Economy mode
– Party mode
– Holiday program
– Heating curves
– Codes
– Actuator tests
Control units
(cont.)
66
VIESMANN
Gas condensing boilers
9
5822 449 GB