Viessmann Vitocal 300 AWO-M-AC 301.A, Installation And Service Instructions Manual

Page: 86 / 152

86
High limit safety cut-out for heat
pump in conjunction with an external
heat source
222.3
222.4
A
X3.1
X2.N
C
B
K1
D
A
Terminals on extension PCB
B Move jumper from X3.1 to 222.3
C Connection on the external heat
source at terminals for external
demand
D
High limit safety cut-out (max. 70
°C) as heat pump protection
K1 Relay; sizing in accordance with the
external heat source; observe
safety instructions
Plug sXD
Terminals Function Explanation
223.1
223.2
U
Central fault message Zero volt contact:
■ Closed: Fault
■ Open: No fault
■ Unsuitable for safety LV.
Connection values (contact loads):
■ Voltage: 230 V~
■ Max. switching current: 4(2) A
Connect on site.
Note
■ No parameters need to be set.
■ The contact issues a short pulse when
the power supply is switched on.
Observe the pulse when processing
the message via communication tools.
Installation sequence
Electrical connections in the heat pump control…
(cont.)
5692 875 GB