Viessmann VITOCAL 242-S Installation And Service Instructions Manual page 48

Installation sequence
Electrical connection
Terminals Function
X3.8 Frost stat and/or contact
X3.9 humidistat, cooling
or
Jumper
X3.18 Heat pump control unit
X2.1 power supply 230 V~
X1.1
Internal unit: Controller and sensor PCB (sensors)
Set the required parameters during com-
missioning: See from page 77.
Plug Sensor
F0.1/F0.2 Outside temperature sensor
F0.2/F0.3 Radio clock receiver (accessories)
F4 Buffer temperature sensor
F11 Contact humidistat 24 V–
Note
If a 230 V~ contact humidistat (connection to
X3.8/X3.9) is used for cooling, set a jumper, oth-
erwise the heat pump will not start (message "CA
Protectn device primry").
F13 System flow temperature sensor (downstream of
heating water buffer cylinder)
F14 Cooling circuit flow temperature sensor (heating
circuit without mixer A1/HC1 or separate cooling
circuit SKK)
F16 Room temperature sensor, cooling circuit
■ Required for separate cooling circuit SKK
■ Recommended for heating/cooling circuit with-
48
(cont.)
out mixer A1/HC1
Explanation
Requires zero volt N/C contact:
■ Closed: Continuous safety chain
■ Open: Safety chain interrupted; heat
pump shut down
■ Breaking capacity 230 V~, 0.15 A
Connection:
■ Connected in series if both safety com-
ponents are installed
■ Insert jumper if no safety components
are installed.
See chapter "Power supply".
Type
NTC 10 kΩ
DCF
NTC 10 kΩ
―
NTC 10 kΩ
NTC 10 kΩ
NTC 10 kΩ