Viessmann Vitocal 300-G Installation And Service Instructions Manual page 87

Electrical connections
Terminals Function
X3.6 Power-OFF
X3.7
G
X3.8 Primary circuit pressure
X3.9 switch and/or frost stat
or
Jumper
P
(cont.)
Explanation
Requires floating N/C contact:
■ Closed: No blocking (safety chain has
continuity)
■ Open: Blocking enabled
■ Breaking capacity 230 V~, 0.15 A
With a connected power-OFF contact, no
jumpers should be installed.
Note
■ No parameters need to be set.
■ The compressor is shut down "hard" as
soon as the contact opens.
■ The supply voltage to the relevant com-
ponents (subject to power supply utility)
is switched off by the power-OFF contact
signal.
■ For the instantaneous heating water
heater, the stages to be switched off can
be selected (parameter "Output for
instant. heating water heater at
power-OFF").
■ The power supply to the heat pump con-
trol unit (3 x 1.5 mm
the power-OFF signal can be combined
in a 5-core cable.
■ For further information regarding power-
OFF, see chapter "Power supply".
Floating contact required:
■ Closed: Safety chain has continuity
■ Open: Safety chain interrupted; heat
pump shut down
■ Breaking capacity 230 V~, 0.15 A
On-site connection:
■ Connected in series if both safety com-
ponents are installed
■ Insert jumper if no safety compo-
nents are installed
Installation sequence
2 ) and the cable for
87