Viessmann BW 301.C090, Installation And Service Instructions For Contractors

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36
Plug sXS
Clamps Function Explanation
222.3
222.4 Control of external heat generators
with 2 high limit safety cut-outs (max.
70 °C) for the heat pump and for
switching off the secondary pump Floating contact
Note
■
The switching contact is a floating N/O contact that
is closed when a heat demand is issued.
■
Never route low voltage via this contact. For that, a
relay must be fitted on site.
■
The boiler water temperature sensor in the external
heat generator (plug F20) must capture the average
temperature of the external heat generator.
Connection values (contact rating):
■
Voltage: 230 V~
■
Max. control current: 4(2) A
Connect the high limit safety cut-out on site:
■
In series with the secondary pump (terminal 211.2
on main PCB), see separate "Connection and wiring
diagram".
■
In series for switching external heat generators, see
separate "Connection and wiring diagram".
Plug
sXD
Clamps Function Explanation
223.1
223.2
U
Central fault message Floating contact:
■
Closed: fault
■
Open: no fault
■
Not suitable for safety LV
Connection values (contact rating):
■
Voltage: 230 V~
■
Max. control current: 4(2) A
Connection, see separate "Connection and wiring dia-
gram".
Note
■
No parameters need to be set
■
The contact issues a short pulse when the power
supply is switched on. Observe the pulse when pro-
cessing the message via communication tools.
Installation sequence
Electrical connections
(cont.)
5787 232 GB
Installation