Viessmann VITOCAL 151-A Installation And Service Instructions Manual page 136

Outdoor unit maintenance
Overview of electrical components
Fig. 84
Terminal strip, 400 V~ power supply
A
Terminal strip, 230 V~ power supply
B
Checklist for maintenance work
Note
Work on the refrigerant circuit must only be carried out
by Viessmann Technical Services employees.
136
Chokes
C
D Fuses for PCB and fans
6.3 A H (slow), 250 V~
VCMU refrigerant circuit controller
E
Coil, 4-way diverter valve
F
Inverter
G
A
Danger
B
Contact with live components can lead to seri-
ous injury from electric current. Some compo-
nents on PCBs remain live even after the power
C
supply has been switched off.
D
■ Never touch electrical terminal areas.
■ When working on the indoor or outdoor unit,
E
isolate the system from the power supply, e.g.
at a separate MCB/fuse or a mains isolator.
Check that it is no longer live. Safeguard
against unauthorised reconnection.
■ Prior to working on the appliance, wait at
F
least 4 min until the voltage has completely
dropped out.
Danger
The absence of system component earthing can
lead to serious injury from electrical current and
component damage in the event of an electrical
G
fault.
All earth conductor connections must be recon-
nected.
The appliance and pipework must be connected
to the equipotential bonding of the building.