Viessmann VITOCAL 300-G Installation And Service Instructions For Contractors page 34

Installation sequence
Electrical connection
Clamps Function
X3.2 In systems without heating water
■
X3.14 buffer cylinder: Temperature limiter
to restrict the maximum tempera-
ture of underfloor heating circuit (if
installed)
or
High limit safety cut-out in conjunc-
■
tion with external heat generator
or
"External blocking" signal: External
■
blocking of compressor and pumps,
mixer in control mode or CLOSED:
Can also be connected at EA1 ex-
tension.
Note
In systems with heating water buffer
cylinder, the temperature limiter is
connected in series to the relevant
heating circuit pump: See chapter
"Temperature limiter to restrict the
maximum temperature of underfloor
heating circuit".
X3.3 Flow switch, well circuit
X3.4
X3.6 Power-OFF
X3.7
G
34
(cont.)
Explanation
Floating contact (N/O contact) required:
Closed: Blocking active
■
Open: No blocking
■
Breaking capacity 230 V~, 2 mA
■
Note
The system may no longer be protected against frost
■
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
Requires floating contact:
Closed: Heat pump operational
■
Open: Heat pump shut down
■
Breaking capacity 230 V, 0.15 A
■
Note
No jumper should be installed if a flow switch is con-
nected.
Requires floating contact:
Closed: Heat pump operational
■
Open: Heat pump shut down
■
Breaking capacity 230 V, 0.15 A
■