Viessmann VITOCAL 300-A Installation And Service Instructions Manual page 87

Electrical connections in the control unit
Required parameters:
Parameter (ID) Ó Setting
"Electric heating"
"Inst.htg.water heat" (7900) Ó "Yes"
&
Power-OFF
The supply voltage to the relevant components (subject to power supply utility)
is switched off by the power-OFF contact signal.
A Terminals on PCB 1
B Zero volt N/C contact
Breaking capacity 230 V~, 0.5A,
remove jumper when making this
connection
Contact open: Power-OFF en-
abled
Installation sequence
(cont.)
Contact closed: Power-OFF dis-
abled
Note
& No parameters need to be set.
& The compressor is switched off as
soon as the contact opens.
& For the instantaneous heating water
heater, the stages to be switched off
can be selected. See parameter
"Stage at power-OFF" (790A) on
page 153.
For further information, see page 97
and 98.
87