Webasto Air Top 2000 ST B Installation Instructions Manual page 33

Legend for circuit diagrams:
Item Description
A1 Heater
A2 Control module
B1 Flame sensor
B2 Temperature sensor
B3 Overheating sensor
B4 Temperature sensor
E Glow plug
F1 Fuse 24 V 15A/12V 20A
F2 Fuse 20 A
F3 Fuse max. 15A
H1 LED, green (in item S1)
H3 LED red (in item P)
H4 Heating symbol in the display
(in item P)
H5 Light (in item P)
H6 Light (at least 1.2 W)
K Relay
with free-wheeling diode
M1 Motor
M3 Motor
P Combination timer (1531)
Resistor 620 Ω
R1
S1 Control element
S2 1 or 2-pin disconnecting
switch
S3 Switch
68
Comment
Air Top 2000 ST
for petrol heater only
internal
Overheating guard
External
Flat fuse SAE J 1284
Flat fuse SAE J 1284
Flat fuse SAE J 1284
Indicator
Light in immediate heat button,
ready indicator,
Switch-on indicator
Indicator
Display and button lights
Switch-on indicator pumping
device
for vehicle fan
Combustion and hot air fan
Vehicle fan
Timer and setpoint generator
With internal temperature
sensor only
Setpoint generator switch
Emergency Stop switch
On and for pumping device
Item Description
S4 Switch
S5 Switch
S6 Switch
S7 Momentary-contact switch
S8 Battery isolation switch
V1 Diode
V2 Diode
X1 Plug connector, 2-pin
X2 Plug connector, 2-pin
X3 Plug connector, 2-pin
X4 Plug connector, 2-pin
X5 Plug connector, 2-pin
X6 Plug connector, 2-pin
X7 12-pin plug connection
X8 Plug connector, 2-pin
X9 Plug connector, 4-pin
X10 Plug connector, 2-pin
X11 Plug connector, 2-pin
X12 12-pin plug connection
Y1 Metering pump
Y2 Solenoid valve
Air Top 2000 ST
Comment
Ventilation
Flashover sensor
CO setting
2
Immediate heat button remote
control
to item A2 (ST B)
to item A2 (ST V)
to item A2 (ST U)
to item A2 (ST Z)
to item A2 (ST Y)
to item A2 (ST X)
to item A2 (ST1)
to item S1
to item Y1
to item P
for pumping device