Viessmann VITOCAL 300-G Installation And Service Instructions For Contractors page 35

Electrical connection
Clamps Function
X3.8
X3.9
Pressure switch, primary circuit
P
and/or
Frost stat
or
Jumper
X3.12 "External demand" signal: External
X3.13 starting of compressor and pumps;
or at external mixer in control mode or OPEN,
EA1 extension changeover of the operating status of
several system components
X40 Heat pump control unit power supply:
Phase L or L1
X40.
?
X40.N Neutral conductor terminal
Controller and sensor PCB (extra low voltage (ELV) connections)
Set the required parameters during commissioning:
See page 51 onwards.
(cont.)
Earth conductor terminal
Explanation
Note
No parameters need to be set
■
No jumper should be installed if a power-OFF contact
■
is connected.
The compressor is "forced" off as soon as the contact
■
opens.
The power-OFF signal switches off the supply voltage
■
of the respective component (subject to the power
supply utility).
For the instantaneous heating water heater, the
■
stages to be switched off can be selected (parameter
"Output for instant. heating water heater at pow-
er-OFF 790A").
The power supply for the heat pump control unit
■
2
(3 x 1.5 mm ) and the cable for the power-OFF signal
can be combined in a single 5-core cable.
In connection with Smart Grid:
The power-OFF signal must not be connected.
Jumper must be installed.
Requires floating contact:
Closed: Safety chain has continuity
■
Open: Safety chain interrupted; heat pump shut down
■
Breaking capacity 230 V~, 0.15 A
■
Connection:
Connected in series if 2 safety components are instal-
■
led
Insert jumper if no safety components are instal-
■
led.
Requires floating contact:
Closed: Demand
■
Open: No demand
■
Breaking capacity 230 V~, 2 mA
■
Note
These and further external functions (e.g. provision of
external set values) can alternatively be connected via
the external EA1 extension.
See "EA1 extension" installation instructions
Power supply 230 V~: See chapter "Power supply".
Installation sequence
35