Viessmann VITOCAL 300-G Installation And Service Instructions For Contractors page 31

Electrical connection
High limit safety cut-out in conjunction with exter-
nal heat generator
X3.1
A
X3.14
222.3
B
222.4
C
K1
X2.N
Fig. 18
High limit safety cut-out to protect the heat pump
A
(max. 70 °C)
Terminals on expansion PCB
B
Connection on external heat generator to terminals
C
for "External demand"
K1 Relay
■ Sizing according to the external heat generator
■ Observe safety instructions.
Plug
sXD
Terminals Function
223.1 Central fault message
223.2
U
Central fault message
223.1
230V~, 0.5 A
A
223.2
Fig. 19
Terminals on extension PCB
A
(cont.)
L1
N
!
Please note
In the case of incorrect parameter setting, the
high limit safety cut-out might not switch off the
secondary pump immediately after being trig-
gered, but instead with a time delay.
Set "Effect of external blocking on pumps/
compressor 701A" to "16" (select "bit 5").
!
Please note
The function of the high limit safety cut-out can
be disabled by other functions.
■ External hook-up, heating/cooling circuits:
External hook-up for heating/cooling circuits
(e.g. in conjunction with a Smart Home sys-
tem) must not be set: Do not set "Remote
control 2003, 3003, 4003" to "2".
■ Smart Grid:
For Smart Grid, use the EA1 extension
(accessories): Set "Enable Smart Grid 7E80"
to "1".
Explanation
Floating contact:
Closed: Fault
■
Open: No fault
■
Not suitable for safety LV
■
Connection values (contact rating):
Voltage: 230 V~
■
Max. switching current: 4(2) A
■
Installation sequence
31