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Vitocrossal 300 CA3 Series 2.5 to 6.0 Installation/Service
Burner Control Unit Connection Diagram
For CA3 2.5 and 3.0 boilers
Legend
A
Boiler temperature sensor 1
§
A
B
Boiler temperature sensor 2
§
B
C
Secondary boiler water temperature sensor 1
aG
A
D
Secondary boiler water temperature sensor 2
aG
B
E
Overfire pressure switch
acA
A
(APS2)
F
Fan motor with PWM control and feedback
a=Ö
A
G
Inlet gas pressure switch
ayA
GDW1
H
Inlet fan pressure switch
acA
(APS1)
K
Gas pressure switch (outlet pressure at first valve
seat)
kJ
GDW2
L
Burner display and programming unit
M
Flame
sensor
aA
N
Solenoid
valve
O
Burner damper
P
Ignition unit
gF
Q
Gas valve V1
dG
R
Gas valve V2
dH
S
Vitotronic control unit
T
AC-EMI suppression filter device
U
Message: Air damper open
F1/F2 Fuse
CAUTION
Provide disconnect means and overload protection as
required.
WARNING
Disconnect power inside the boiler junction box, before
servicing boiler.
Connection and Wiring Diagrams