Viessmann VITOCAL 300-G Installation And Service Instructions For Contractors page 42

Installation sequence
Power supply
(cont.)
Instantaneous heating water heater power supply 400 V~
!
Please note
Operating the instantaneous heating water
heater without heating water damages the indi-
rect coil.
Only connect the instantaneous heating water
heater to the power supply after the heating sys-
tem has been completely filled and vented.
L1 L2 L3 N
L1 L2 L3 N
3/N/PE 400 V/50 Hz
Fig. 31
Power supply with power-OFF: Without on-site load disconnect
The power-OFF signal is connected directly to the heat
pump control unit. The compressor is "forced" off when
power-OFF is enabled.
Parameter "Output for instant. heating water heater
at power-OFF 790A" determines whether and at what
stage an instantaneous heating water heater remains
operational during the power-OFF period.
Note
Observe the technical connection conditions of the rel-
evant power supply utility.
42
Economy tariff and power-OFF can be used
■
No parameters need to be set when using economy
■
tariff with power-OFF. The compressor is shut down
during the power-OFF time.
Cable Max. cable length
2
5 x 2.5 mm
X3.7
A
X40
X3.6
3
≈
3
kWh
G
3/N
H
F
4
E
Fig. 32 Diagram excluding fuses and RCD
Heat pump control unit
A
Instantaneous heating water heater
B
Compressor
C
Economy tariff meter
D
Feed: TNC system
E
Backup fuse, ripple control receiver
F
Ripple control receiver (contact open: Power-OFF
G
enabled)
Premium tariff meter
H
Fuse rating
25 m 16 A
B
C
5 5
3
kWh
3/N
D
4
4