Viessmann VITODENS 200-W Technical Manual page 41

Control units
(cont.)
DHW heating in a multi-boiler system
A Vitotronic 300-K
Control characteristics
■ PI characteristics with three-point output
■ Setting range for heating curves:
– Slope: 0.2 to 3.5
– Level: –13 to 40 K
– Max. limit: 1 to 127 °C
– Min. limit: 1 to 127 °C
– Differential temperature for a heating circuit with mixer: 0 to 40 K
■ Set DHW temperature range:
10 to 60 °C, adjustable to 10 to 95 °C (available temperature limited
by the max. boiler flow temperature).
Time switch
Digital time switch
■ Day and week program, annual calendar
■ Automatic summer/winter time changeover
■ Automatic function for DHW heating and DHW circulation pump
■ Time, day and standard switching times for central heating, DHW
heating and the DHW circulation pump are factory-set
■ Switching times are individually programmable, i.e. up to four switch-
ing periods per day
Shortest switching interval: 10 minutes
Power backup: 5 years
Setting heating programs
The heating system frost protection (see frost protection function)
applies to all heating programs.
You can select the following operating programs with the program
keys:
■ Heating and DHW
■ Only DHW
■ Standby mode
Optional external changeover of heating program for all heating cir-
cuits together or for selected heating circuits only.
Frost protection function
■ The frost protection function will be started when the outside tem-
perature drops below approx. +1 °C.
With frost protection, the heating circuit pump is switched ON and
the boiler water is maintained at a lower temperature of approx.
20 °C.
The DHW cylinder will be heated to approx. 20°C.
■ The frost protection function will be stopped when the outside tem-
perature rises above approx. +3 °C.
Summer mode
("DHW only")
One or several burner(s) start(s), when the DHW cylinder needs to be
heated up (controlled by the cylinder temperature control unit).
VITODENS 200-W
A
M M
Adjusting the heating curves (slope and level)
Subject to heating system:
■ The Vitotronic controls the flow temperature of up to 2 heating cir-
cuits with mixer in weather-compensated mode
■ The Vitotronic controls the system/flow temperature automatically 0
to 40 K (delivered condition 8 K) higher than the current maximum
set flow temperature
The flow temperature required to reach a specific room temperature
depends on the heating system and the thermal insulation of the build-
ing to be heated.
Adjusting the heating curves matches the system flow temperature
and the heating circuit flow temperature to these conditions.
The upper flow temperature is limited by temperature controller "R"
and the electronically set maximum temperature of the Vitotronic 100
boiler control units, type HC1A.
Outside temperature sensor
Installation location:
■ North or north-western wall of the building
■ 2 to 2.5 m above the ground, for multi-storey buildings in the upper
half of the second floor
Connection:
■ 2-core lead, length up to 35 m with a cross-section of 1.5 mm
per).
■ Never route this lead immediately next to 230/400 V cables
Heating curve slope
90
80
70
60
50
40
30
20
20 15 10 5 0 -5 -10 -15 -20
Outside temperature in °C
1.4 5
1.2
1.0
0.8
0.6
0.4
0.2
-25 -30
2 (cop-
VIESMANN
41