baltur TBG 120 P Installation, Use And Maintenance Instruction Manual page 54

ENGLISH
• If necessary, correct the combustion air supply adjusting the
screw(s) -11 as described previously.
• Check the combustion parameters in the 1st stage with appropriate
instruments (CO2 MAX=10% O2 MIN= 3% CO MAX=0.1%)
• The air pressure switch prevents the opening of the gas valves
if the air pressure is not the foreseen one. The pressure switch
must therefore be adjusted to intervene closing the contact when
the air pressure in the burner reaches a sufficient value. If the
air pressure switch does not detect a pressure greater than that
calibrated, the equipment runs through its cycle but does not
switch on the ignition transformer and the gas valves do not open,
consequently the burner "locks-out". To ensure correct operation of
the air pressure switch you must, with burner lit and in first stage,
increase its regulation value until the burner triggers after which
it must immediately "lock out". Release the burner by pushing
the appropriate button -9 and readjust the pressure switch to a
sufficient value to detect the existing air pressure during the pre-
ventilation phase of the first stage.
• The control pressure switches for the gas (minimum) are to prevent
the working of the burner when the pressure of the gas is not as
provided for. The minimum pressure switch must use the contact
that is closed when the pressure switch detects a pressure higher
than the value it is set to. The minimum pressure switch regulation
must be done upon burner start-up according to the pressure
detected each time. The triggering (opening of the circuit) of any
of the pressure switches when the burner is running (flame on)
causes the burner to stop immediately. Upon first ignition of the
burner, it is essential to check that it works properly.
• Check for the triggering of the ionisation electrode by disconnecting
the jumper between terminals 30 and 31 on the printed circuit
board and start the burner. The equipment must run through its
cycle completely and, three seconds after the ignition flame has
formed, "lock-out". This check should also be carried out with the
burner already lit. The apparatus should lock out immediately when
the jumper between terminals 30 and 31 is disconnected.
• Check for the efficiency of the thermostats or boiler pressure
switches (they should shut down the burner when triggered). Check
that the ignition takes place properly. In the event that the mixer is
too far forward, it may happen that the speed of the delivery air is
so high that ignition is difficult. If this happens, the mixer must be
gradually shifted back until it reaches a position in which ignition
occurs regularly, and this position can be regarded as the final
position. For the first stage, it is preferable to limit the quantity of air
to that which is strictly necessary for safe ignition, even in the most
difficult circumstances.
DANGER / CAUTION
Once the adjusting operations are completed, visually check
that the thin plate on which the bearing acts has a progressive
profile. Also check trough the dedicated tools that during the
passage between first and second stage the combustion
parameters do not excessively vary from the optimal values.
POWER AT START-UP
The standard EN 676 prescribes that for burners with maximum
output above 120 kW the ignition must occur at a lower power Pstart
than the maximum power of operation Pmax at which the burner is
calibrated.
Pstart it depends on the safety time of the burner equipment; in
particular:
ts = 2s → Pstart ≤ 0,5
ts = 3s → Pstart ≤ 0.333
Example if the maximum burner output regulation Pmax is 900 kW,
it should be:
Pstart ≤ 450 kW with ts = 2s
Pstart ≤ 300 kW with ts = 3s
Check the output at ignition
• Disconnect the flame sensor cable (in this case the burner lights
up and locks out after the safety time ts).
• Switch on 10 times with consequent lock-outs.
Measure at the meter the amount of gas burned Qstart [m³] and
•
check that Qstart ≤ Pmax /360 (Pmax in m³/h)
Example
Pmax = 90 m³/h (approx. 900 kW with natural gas)
After switching on 10 times with consequent lock-outs, the gas
consumed measured by the meter should be:
Qstart ≤ 90/360 = 0.25 [m³]
If this does not occur, reduce the flow of gas to the ignition through
the brake of the valve.
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x Pmax.
x Pmax.