Viessmann Vitocal 300-G BW, Installation And Service Instructions Manual

Page: 86 / 216

86
Danger
Incorrectly executed electrical
installations can lead to injury
through the transmission of dan-
gerous body currents and result
in equipment damage.
Carry out the power supply con-
nection and all earthing meas-
ures (i.e fault current circuit) in
accordance with IEC 364, the
requirements of your local power
supply utility, VDE or local and
national regulations.
Main isolator requirements (if necessary)
If a main isolator is set, it must isolate the
power circuit with at least 3 mm contact
separation. If no main isolator is set, all non-earthed
cables must be isolated by the upstream
MCB with at least 3 mm contact separa-
tion.
General information regarding the power supply
The power supply is separated into 3
areas:
■ Control unit power supply (electronics)
■ Heat pump compressor power supply
(main power circuit)
■ Instantaneous heating water heater
power supply (accessory, main power
circuit)
Note
■ Protect the power cable to the control
unit with a fuse of max. 16 A.
■ The mains fuses for the compressor
must have Z characteristics, if a full
wave soft starter is installed (see type
plate or specification from page 203).
■ We recommend making the power
connection for accessories and exter-
nal components to the same fuse, with
at least the same phase as the control
unit.
■ Connection to the same fuse provides
additional safety when the power is
switched off. However, observe the
power consumption of the connected
consumers for this (control unit fuse
protection max. 16 A).
■ If the compressor and/or the instanta-
neous heating water heater are oper-
ated at a lower tariff (power-OFF), pro-
vide an additional cable for the switch-
ing contact "power-OFF" (e.g. NYM
3x1.5 mm
2 ) from the distribution board
(meter box) to the heat pump.
Installation sequence
Power supply
5368 522 UAE