Safety Chain (Explanations) - Viessmann Vitocal 300-G BW Installation And Service Instructions Manual

PCB 3: Sensors and KM BUS
Sensor / KM BUS
Sensor, external heat source
KM BUS

Safety chain (explanations)

The following diagrams showing the
safety chain contain the individual safety
elements.
The test points are identified with figures
1 and 4 to qP and refer to the termi-
nals marked accordingly on the 10-pole
terminal block behind the contact shield
(see figure on page 59).
For further details regarding the PCBs
and terminal markings, see from
page 61.
Symbols and abbreviation key
L' Switched phase
N' Switched neutral conduc-
tor
Connection and wiring diagrams
(cont.)
Type ID
Pt 500 F20
— KM
BUS
Power-OFF Power supply utility block
DSW Three phase monitor
Brine P Brine pressure switch
Frost protection monitor
Çϑ
ϑ brine 1
Thermal circuit breaker for
the brine pump
SHD1 Safety high pressure
switch
ND1 Low pressure switch
RHD1 Control high pressure
switch
VSA1 Full wave soft starter
MSS1 Protective motor switch
K1 Relay, compressor control
EEV Electronic expansion valve
Connection
3X1.4 / 3X2.4
3X1.25 / 3X2.25
179