Viessmann Vitocal 252-A Series - Page 73

73
The following functions are available via the 4 digital inputs:
Functions Switching contacts Explanation
143.2 143.3 143.4 143.5
Power-OFF
G
— — X — Requires floating N/C contact:
■
Closed: Heat pump operational
■
Open: Heat pump shut down
■
For the instantaneous heating water heater, the
stages to be switched off can be selected.
■
The power supply for the heat pump control unit
(3 x 1.5 mm
2
) and the cable for the power-OFF signal
can be combined in a single 5-core cable.
■
For further information regarding power-OFF: See
chapter "Power supply".
In connection with Smart Grid:
Do not connect the power-OFF signal.
143.4
A
143.1
A
Floating contact (on site)
Smart Grid — — X X The power-OFF function is integral to Smart Grid. The
power-OFF signal must therefore not be connected.
143.4 143.5
A
B
143.1
A
Floating contact (on site)
B
Floating contact (on site)
DHW circulation
pump demand
X — — — External demand, DHW circulation pump
143.2
A
143.1
A
Floating contact (on site)
Electrical connections
Electrical connection of the indoor unit (cont.)
6222080
Installation