57
Plug
sXS
Terminals
Function
Explanation
222.3
222.4
Switching external heat
sources with two high limit
safety cut-outs (max. 70 °C)
for the heat pump and to
shut down the secondary
pump
Floating contact
Note
■ The switching contact is a zero volt
N/O contact that is closed when a heat
demand is issued.
■ Never route low voltage via this con-
tact; that requires an on-site relay.
■ The boiler water temperature sensor in
the external heat source (plug F20)
must capture the average temperature
of the external heat source.
Connection values (contact loads):
■ Voltage: 230 V~
■ Max. switching current: 4(2) A
Connect the high limit safety cut-out on
site:
■ In series with the secondary pump (ter-
minal 211.2 on main PCB), see sepa-
rate "connection and wiring diagram"
sheet 20
■ In series for switching external heat
sources, see separate "connection
and wiring diagram" sheet 170,
sheet 171, sheet 172
Installation sequence
Overview of electrical connections
(cont.)
5772 458 GB
Installation
