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5790 733 - 07
Vitocrossal 300 CA3 Series 2.5 to 6.0 Installation/Service
Function Description
Heating Circuit Control
(continued)
Supply temperature control single boiler control unit
Differential temperature:
The differential temperature can be set at coding “9f”
in the “General”group, factory set condition: 15°F (8 K).
The differential temperature is the minimum value by
which the boiler water temperature should be higher
than the highest currently required supply temperature
of the heating circuit with mixing valve.
H
System with only one heating circuit with mixing valve:
The set boiler water temperature will be automatically
regulated to 15°F (8 K) above the set supply temperature.
H
System with heating circuit without mixing valve and
heating circuit with mixing valve:
The set boiler water temperature operates in
accordance with its own heating curve. The differential
temperature of 15°F (8 K) towards the set supply
temperature is set at the factory.
Supply temperature control cascade control unit
Differential temperature:
The differential temperature can be set at coding “9f”
in the “General” group, factory set condition 15°F (8 K).
The differential temperature is the value by which the
common supply temperature should be higher than the
highest currently required supply temperature of the
heating circuit with mixing valve.
H
System with only one heating circuit with mixing valve:
The common set supply temperature is regulated
automatically to 15°F (8 K) above the set supply
temperature of the heating circuit with mixing valve.
H
System with heating circuit without mixing valve and
heating circuits with mixing valve:
The common set supply temperature operates in
accordance with its own heating curve. The differential
temperature of 15°F (8 K) towards the set supply
temperature of the heating circuits with mixing valve
is set at the factory.
Legend
A
Max. boiler water temperature
B
Slope = 1.8 for heating circuit without mixing valve
C
Slope = 1.2 for heating circuit with mixing valve
D
Boiler water temperature [with a differential
temperature = 15°F (8 K)]
E
Lower boiler water temperature, defaulted by the
boiler coding card
Legend
A
Maximum supply temperature limit
(coding “37” in the “Cascade” group)
B
Slope = 1.8 for heating circuit without mixing valve
C
Slope = 1.2 for heating circuit with mixing valve
D
Common supply temperature [at a differential
temperature = 15°F (8 K)]
E
Lower common supply temperature
Supply temperature
