02/2011 - Art. Nr. 4200 1027 9501B
4
Operation
Safety function
Description of the function
A pre-ventilation time of 24 seconds
begins when first powering up, after a
power cut or a lockout, after the gas
supply has been cut or after a shutdown
for 24 hours.
During the pre-ventilation time
- the air pressure is monitored
- the combustion chamber is monitored
to detect any flame signals.
At the end of the pre-ventilation time
- the ignition is switched on
- the main and safety solenoid valves
are opened.
- burner start-up
Monitoring
The flame is monitored by an ionisation
probe. The probe is fitted with insulation
to the gas head and is routed through
the turbulator into the flame zone. The
probe must not have any electrical
contact with earthed parts. The burner
switches to malfunction if a short circuit
occurs between the probe and the
burner earth. During burner operation,
an ionised zone is produced in the gas
flame through which a rectified current
flows from the probe to the burner tip.
The 2
nd
stage ionisation current must be
at least 7 µA.
Safety functions
- If no flame is produced when the
burner is started (gas release), the
burner is switched off at the end of the
safety time which lasts no more than
3 seconds and the gas valve closes.
- If the flame is lost during operation, the
gas supply is cut within a second. A
new start-up sequence is activated. If
the burner starts, the operating cycle
starts running. Otherwise a lockout
occurs.
- If there is an air failure during pre-
ventilation or operation, a lockout
occurs.
- If there is a gas failure, the burner
either stops or will not start. As soon
as the gas pressure recovers a
sufficient value, burner starts again.
During the regulator shutdown
- The control thermostat interrupts the
heat request.
- The gas valves close
- The flame goes out
- The burner is ready for operation
Compact train
CH note
In accordance with SSIGE instructions,
it is compulsory to install a gas safety
valve (mark
1
) in the pipe
DE Note
In compliance with the reference layout
applicable to boiler rooms, sites with gas
furnaces must be fitted with a thermal
gas shut-off valve (mark
1
).
F4
Gas pressure switch
F6
Air pressure switch
Y12 Safety solenoid valve
Y13 Solenoid valve, 1st stage
Y14 Solenoid valve, 2nd stage
1
Thermal shut-off valve (to be
installed by the installer)
104 Gas pressure regulator
106 Screen
108 Gas cut-out valve (to be installed
by the installer)
119pBrGas pressure measuring point at
the valve outlet
119.1Gas pressure measuring point
upstream of the valves
119.2Air pressure measuring point
Combustion
Control
ltd
