Viessmann Vitocal 300-G Installation And Service Instructions Manual page 86

Installation sequence
Electrical connections
Terminals Function
X3 ■ Power supply terminals
of the control unit "L1"
and auxiliary compo-
nents
■ Switched phase L1:
X3.1, X3.2, X3.3, X3.7,
X3.11, X3.13
X3.1 Phase switched
X3.2 Signal "External blocking"
X3.14 (external blocking of com-
or at exter- pressor and pumps, mixer
nal exten- in control operation or
sion H1 CLOSED)
Note
The system may no longer
be protected against
frost.
X3.3 Flow limiter, well circuit
X3.4
86
(cont.)
Explanation
Terminals for message and safety connec-
tions
Note
Switched phase can be used for on-site
system components. Observe max. load.
Requires floating N/O contact:
■ Closed: Blocking enabled
■ Open: No blocking
■ 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 exter-
nal extension H1.
Installation instructions "External
extension H1"
■ If a swimming pool water heating facility
is connected to external extension H1,
no other external function can be con-
nected to external extension H1.
Floating contact required:
■ Closed: heat pump operational
■ Open: Heat pump shut down
■ Breaking capacity 230 V~, 0.15 A
With a connected flow limiter, no jumpers
should be installed.