Technical data

7 Circuit Diagrams Thermo 230 / 231 / 300 / 301 / 350
702
Fig. 701 Automatic Control Circuit with Control Unit 1572 and Switch
33
51
15
62
2
6
1
2
44
4
3
3
2
2
1
1
4
F1
B2
Y1
br gr or gn
ϑ
ϑ
rt/ws
bl
or
br
br
sw
rt
sw
A2
X1 A
X3
D
X2
C
K2
K1
M1
M2
H2H1
B3
B4
S2
S3
S4
S1
A1
B1
E1
U2
U1
SE
-
+
M
M
M1
A2
U1
A1
B1 Y1
F1/B3
E1
B2
br
F3 F2
30
30
31
31
X3
8
7
6
5
4
3
2
1
2
1
X2
X1
1
3
5
2
4
6
D
C
A
6
5
4
3
2
1
1
bl
br
ge
gn
gr
or
rt
sw
vi
ws
Wire colors
blue
brown
yellow
green
gray
orange
red
black
violet
white
Wire gauges
< 7.5 m 7.5 - 15 m
0.75 mm
2
1.0 mm
2
1.5 mm
2
2.5 mm
2
4.0 mm
2
1.5 mm
2
1.5 mm
2
2.5 mm
2
4.0 mm
2
6.0 mm
2
Item Nomenclature Remark
S3 Switch, external trigger
circulation pump
S4 Switch power save operation
U1 Igniter box
U2 Igniter electrodes
A Plug connections, 6-pole
C Plug connections, 1-pole
D Plug connections, 4-pole
X1 Plug connections, 6-pole
X2 Plug connections, 2-pole
X3 Plug connections, 8-pole
Y1 Solenoid valve
1 Diagnostic connector
Item Nomenclature Remark
A1 Heater not grounded
A2 Control unit SG 1572
B1 Flame sensor
B2 Temperature sensor
B3 Temperature limiter
B4 Thermostat open at T > 8 °C
E1 Heating cartridge for nozzle preheating
F2 Fuse 25A flat fuse SAE J 1284
F3 Fuse 25A flat fuse SAE J 1284
H1 Light operation indicator light
K1 Relay (in item A2) for circulation pump
K2 Relay (in item A2) for combustion air fan /
heating cartridge
M1 Motor combustion air fan
M2 Motor circulation pump
S1 Switch on / off
S2 Continuity switch on water cock