Viessmann VITOCAL 151-A Installation And Service Instructions Manual page 43

Electrical connection
Overview of electrical terminal areas
A
B
C
D
Fig. 33
Upper PCB
A
■ Upper luster terminal:
BUS connections
Bottom luster terminal:
■
Sensors
Bottom PCB
B
■ Upper luster terminal:
230 V~ components and digital inputs
■ Bottom luster terminal:
Mains terminals for control unit and instantane-
ous heating water heater
Opening electrical terminal areas
!
Please note
Electronic assemblies can be damaged by elec-
trostatic discharge.
Before beginning work, touch earthed objects,
e.g. heating or water pipes, to discharge any
static.
(cont.)
E
HPMU electronics module
C
HMI programming unit
D
EHCU electronics module
E
Installation sequence
43