Operating Description - Schwank infraSchwank D Series Technical Manual

8 Operating
description
Start-up
If heat demand exists, the fan will start up
automatically. A differential pressure arises in the
burner box, which is reported to the ignition unit via
the differential pressure switch.
After a pre-purge period of about 25 seconds the
automatic ignition starts [max. ignition time 5 sec.].
The twin solenoid valve with pressure regulator
opens the gas supply to the burner in 2 steps. The
burner flame is controlled by an ionisation
electrode. The ignition is switched off, if the
ionisation electrode reports a flame to the burner
control unit IC 4000/1 within the safety time.
If the ignition process fails, the burner control IC
4000/1 repeats the start-up for one more time.
Operation
A very long laminar flame is created in the first
tube by the special burner construction. The hot
flue heats the tube surface while being fed
through the tubes by the fan. The hot tubes emit
long-waved infrared radiation which is directed to
the room by the reflector construction.
The radiant tube infraSchwank D / calorSchwank D
work with a closed combustion system. The
combustion air is taken from the room or from the
outside. The flue is evacuated indirectly into the
room or directly by the exhaust pipe or by a
special air/exhaust pipe system.
For optimal adaption of heaters´ performance to
the heat demand of the building heaters are
offered in modulating operation.
Start and ignition of the heater has always to be in
full load. After a time of minimal 1 minute the
heater can be switched to small step.
infraSchwank D / calorSchwank D shape U
Fault
If no flame is reported during the pre-purge period
[including 1 repetition of ignition process], the
burner control unit IC 4000/1 will switch off the
radiant tube, error will give, fan runs in post-purge
time for 30 seconds and then heater will lock it.
Investigation and repair must be carried out by
authorized personnel only. After clearance of the
fault, the lock can be reset.
The cause of the fault / error code is displayed on
the central control unit SchwankControl Touch or
can read out via corresponding service software.
See chapter 12 for error codes.
Lock release can carry out by activate the reset
command via the central control unit
SchwankControl Touch or an interruption of the
electric power supply for 3 sec. A new start-up
begins. If no flame signal is reported to the burner
control unit IC 4000/1 during operation, the gas
valve shuts and stops the gas supply immediately.
A new start-up process is repeated.

Error codes and troubleshooting on
pages 51 - 52
Monitoring of the combustion air supply
The combustion air supply is permanently
controlled by the differential pressure switch during
the operation.
If the differential pressure switch is not in rest
position during the start-up the operation will not
start. If the operating contact is not closed during
the pre-purge the system will set in interference
release.
If combustion air supply fails during operation [lack
of air], the differential pressure switch will close the
gas combination valve and stop the gas supply. A
new start-up process is to be repeated.
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