Viessmann VITOCAL 300-G PRO Installation And Service Instructions Manual page 65

Overview of electrical connections
Signal and safety connections
Terminals Function
PE/X1. Earth conductor
LP1.X2.N Neutral conductor
LP1.X3.16 Phase L1
LP1 X3.2 Signal "External blocking"
LP1 X3.14 (external blocking of com-
or at H1 ex- pressor and pumps, mixer
ternal ex- in control operation or
tension CLOSE)
Note
The system may no longer
be protected against
frost.
LP1 X3.3 Flow switch, well circuit
LP1 X3.4
LP1 X3.6 Power-OFF
LP1 X3.7
G
(cont.)
Explanation
Terminals for earth conductor of all asso-
ciated system components
Terminals for the neutral conductor of the
heat pump control unit.
Wired at the factory.
Control unit power supply.
Wired at the factory.
Requires floating N/O contact:
■ Closed: Power-OFF enabled
■ Open: No power-OFF
■ Breaking capacity 230 V~, 2 mA
Note
■ These and further external functions,
such as swimming pool water heating,
cascade or external set value default
can alternatively be connected via H1
external extension (see installation in-
structions "H1 external extension").
■ If a swimming pool heating facility is con-
nected to H1 external extension, no oth-
er external function can be connected to
H1 external extension.
Requires floating contact:
■ Closed: Heat pump operational
■ Open: Heat pump shut down
■ Breaking capacity 230 V~, 0.15 A
There should be no jumper if a flow switch
is connected.
Requires floating N/C contact:
■ Closed: No power-OFF (safety chain
has continuity)
■ Open: Power-OFF enabled
■ Breaking capacity 230 V~, 0.15 A
No jumper should be installed if a power-
OFF contact is connected.
Installation sequence
65