4.11 Electrical diagram
T001871-H
2 3
1
K1
X1
X14
X13
X12
X3
X2
X4
X5
X6
X7
X8
X9
X10
X11
HLS
1 2
7 8 9 1 0
X12
3 4
5 6
X6
1 2 3
GN/
YW
WH
BL
GB
1
5
3
X21
X8
1 2 3
PUMP A
BR
BL
GN/
YW
3 1 2
X41
SCU-C
X11
1 2 3 4 5 6
WH
GY
RD
GN
YW
OR
DV
X7
1 2 3
WH
BK
RD
1 3 2
X121
IT
X5
2 3 4 1
E
BK
BL
GN/
YW
GY
1 2
3
X22
PWM
PUMP
12 13
BK
BK
1 2
X116
FTS
RTS
9
RD
1
BK
1
2
2
X115
8
BL
1
2
2
X114
PS
10 11
BK
BK
3 1
X112
FS
2 3
BK
BK
1 3
X113
X10
4 5 7 6
X111
BK
BK
BK
BK
1 2 3 4
PSU
X9
2 3 4 5
X91
BK
BK
BK
BK
1 2 4 5
FAN
1
BK
BK
1
2
X117
P
230V, 50Hz
L N
SCU-C
X2
1
3
2
BL
BR
GN/
YW
X1
1
2
3
BR
BL
GN/YW
X3
4
3 2 1
5
BR
BL
BR
BL
GN/
YW
3 1
4 2
X51
S
DIS
P
Power supply
DV
Inverter valve
FTS
Flow sensor
SCU-C
control panel PCB
PUMP A
Modulating control on the
boiler pump
PS
Pressure sensor
S
On/Off switch
HLS
Safety thermostat
PSU
Parameter storage for PCBs
PCU and SU
IT
Ignition transformer
FAN
Fan
PWM PUMP
Modulation signal from the
boiler pump
E
Ignition power relay
FS
Flowmeter
DIS
Display
GB
Combined venturi and gas valve
unit
RTS
Return sensor
MCA 15 - MCA 25 MCA 25/28 MI
4. Installation
29/04/2010 - 300022146-001-B
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