3 Description of function
NGW 300 / LGW 300 / GBW 300
302
Fig. 301 Operating cycle
3.4.4 Shutdown of the heater when there is low
voltage
When there is low voltage of < 21.5 V, a fault lock-out and
an after-run occur. The heater is in a holding pattern
(control pause). If the voltage goes up again within 20
seconds to > 22.0 V, the heater starts anew.
3.4.5 Shutdown of the heater when theree is
low voltage (not a fault lock-out)
If there is high voltage of more than 30 V for longer than
6 seconds, the users are shut down and the heater finds
itself in a holding pattern after the after-run.
If the voltage drops again to below 30 V, the heater will
switch itself on again.
3.4.6 Fault lock-out when there is a flame but
the solenoids are deactivated
Upon detection of a flame when the solenoids have been
deactivated by the control unit, the heater is shut down
with an error.
In the error after-run , the fan motor is immediately shut
down, the circulating pump will continue to run until the
end of the error after-run.
–
The operating indicator light blinks.
If there is a short circuit in the solenoids, with UB (terminal
30) the heater becomes locked.
The lock may be removed from the heater, only after the
cause of the fault has been removed. (see 3.5).
Where there are deactivated albeit permeable solenoids,
the heater will not be locked. After the cause of the fault
has been eliminated, the heater can be put into operation
once more by switching it on, off and on again,
Operating indicator
Circulating pump
Ignition spark
generator
Combustion air fan
Solenoid
Vacuum switch
Flame monitor
1
Main switch “ON”
2
Start
3
Formation of flames
4
Upper switching threshold
5
Lower switching threshold
6
Switch off
7
Heater off
A Temperature monitoring
B Supply
C Extraneous light monitoring
D Preliminary ignition
E Flame ignition
F Flame stabilisation
G Firing operation
H After-run (control pause 1/
CONTROL
Control pause 1
