Viessmann VITOPLEX 200 Type SX2A Technical Manual page 59

Control units
(cont.)
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
■ The frost protection function is switched on if the temperature drops
approx. +1 °C below the outside temperature, i.e. the heating circuit
pump is switched on and the boiler water is maintained at a lower
temperature (see chapter "Operating conditions with Vitotronic boiler
control units").
■ "Standby mode":
The frost protection function is switched off if the outside temperature
is exceeded by approx.+3 °C, i.e. the heating circuit pump and
burner are switched off.
■ "Heating and DHW"
The frost protection function is switched off if the outside temperature
is exceeded by approx. +3 °C, i.e. the heating circuit pump is
switched off and the low-end boiler water temperature required for
the relevant boiler is maintained as necessary (see chapter "Oper-
ating conditions with Vitotronic boiler control units").
Summer mode
("DHW only")
The burner starts only when the DHW cylinder needs reheating (con-
trolled by the cylinder thermostat).
The respective low-end boiler water temperature of each boiler is
maintained if necessary.
Adjusting the heating curves (slope and level)
The Vitotronic 300 controls the boiler water temperature (=system flow
temperature) and the flow temperature of the heating circuits with
mixer in weather-compensated mode. The boiler water temperature is
automatically boosted by between 0 and 40 K above the currently
required set flow temperature (delivered condition 8 K).
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 both heating curves matches the boiler water temperature
(= system flow temperature) and the flow temperature to these oper-
ating conditions.
The upper boiler water temperature is limited by the thermostat and
the electronic maximum temperature limiter.
OIL/GAS BOILERS
Slope
110
100
90
80
70
60
50
40
30
20 15 10 5 0 -5 -10 -15 -20
Outside temperature in °C
Specification
Rated voltage
Rated frequency
Rated current
Power consumption
Protection class
IP rating
Function
Permissible ambient temperature
– during operation
– during storage and transport
Rated capacity of the relay outputs
sÖ Heating circuit pumps
or
Primary pump, primary store system
or
Circulation pump - flue gas/water
heat exchanger, if installed
or
Switching output
sA Circulation pump for cylinder heat-
ing
sK DHW circulation pump
sL Shunt pump
gÖ Central fault message
gS Mixer motor
or
Mixer motor constant return temper-
ature control
or
Motor, 3-way mixing valve, primary
store system
Total sÖ, sA, sK, sL, gÖ, gS
fA
Burner
lÖ
Burner, two-stage, if installed
lÖ Burner, modulating, if installed
1,8
1,6
1,4
1,2
1,0
0,8
0,6
0,4
0,2
-25 -30
230 V~
50 Hz
2 x 6 A
10 W
11
I
IP 20 D to EN 60529;
ensure through appro-
priate design/installa-
tion
Type 1B to
EN 60 730-1
0 to +40 °C
Installation in living
spaces or boiler rooms
(standard ambient con-
ditions)
-20 to +65 °C
4(2) A, 230 V~
4(2) A, 230 V~
4(2) A, 230 V~
4(2) A, 230 V~
4(2) A, 230 V~
0.2(0.1) A, 230 V~
max. 6 A, 230 V~
4(2) A, 230 V~
1(0.5) A, 230 V~
0.2(0.1) A, 230 V~
VIESMANN
59