Viessmann VITOCAL 151-A Installation And Service Instructions Manual page 51

Electrical connection
Functions
143.2
External blocking X
Heating/cooling X
circuits tempera-
ture limiter 1
HPMU electronics module: Accessory 230 V~ and BUS connection
40 156 156
L N N ? L N
? ? ?
F1 T6.3 A
Fig. 41
F1 Fuse 6.3 A H (slow)
Make all connections with flexible cables.
230 V~ connections
Terminals Component
156.N Switched mains output for mains connec-
156. tion, accessories, e.g. mixer extension kit
156.L
(cont.)
Switching contacts
143.3 143.4 143.5
— — —
— — —
P1 P2 96
X4
L N? L N ? L N ? L 1
Explanation
External blocking of refrigerant circuit and instantane-
ous heating water heater
Temperature limiter to restrict the maximum tempera-
ture of underfloor heating circuits
143.1 143.2
A
Temperature limiter heating/cooling circuit 1
A
91
74 5 1
X5 L GND H
Explanation
Output: 230 W
■
Voltage: 230 V~
■
Max. switching current: 1 A
■
Recommended flexible connecting cable:
2
3 x 1.5 mm
■
Max. cable length: 50 m
■
Installation sequence
91
L GND H
51