COMMISSIONING
Reference should be made to the
Burner Gas Controls and Adjustment
section of this manual for identification
and location of the following
adjustments.
None of these adjustments should
be made in isolation. One
adjustment will have an effect on
another. It is therefore essential that
the combustion quality and gas
throughput are monitored during the
commissioning procedure
PILOT BYPASS ADJUSTMENT
(B07 VALVE ONLY)
The bypass valve opens at the same
time as the first valve. Ignition gas
flow is set by using bypass restrictor.
Turn anticlockwise to increase and
clockwise to decrease rate.
If the governor pressure is set too low
there will be insufficient pressure for
the pilot bypass to operate.
MAIN GAS GOVERNOR
With a screwdriver turn the adjusting
screw to its minimum position then
turn back four complete revolutions.
This will give a reduced gas flow rate
to enable further adjustments to
commence.
Note: Should the burner lockout
when establishing start and main
flames then the probable cause is
air or inert gas in the gas line. This
can be removed by purging the line
through the pressure test points
located on the gas MultiBloc.
Alternatively, there may be
insufficient pressure on the gas
governor.
SETTING MAIN FLAME GAS RATE
Switch the burner on and allow it to
establish main flame.
Check the gas throughput with a gas
meter or with other approved
measuring instrument.
With a screwdriver slowly adjust the
gas governor to increase the gas
volume through the burner to the rate
required for the appliance.
Ensure that other appliances served
by the same meter are isolated when
gas throughputs are being adjusted.
With the gas flow rate for main flame
set and the burner running with stable
flame, the flue gases can now be
checked for CO
2
and O
2
with suitable
combustion testing instruments.
Figures of 9-10% CO
2
and 3-5% O
2
are acceptable. For reasons of safety
the CO (carbon monoxide) should be
checked and should not exceed 100
ppm.
To achieve good combustion
efficiency or if the CO content is
exceeded, adjustments to the air and
gas settings can now be made while
the burner is running on main flame.
ADJUSTING THE MAIN VALVE
FAST INITIAL LIFT.
B01 VALVE
- The adjuster acts as a
damper to the main valve, controlling
the rate of opening after initial lift. This
adjustment is used to reduce the
volume of gas that the valve passes
during the ignition safety phase.
Switch off and restart the burner.
Note the quality of the light up during
the ignition stage. If the light up is
weak, then increase the amount of
fast initial lift by turning the adjuster
anticlockwise. Turn the adjuster
clockwise if a heavy light up is
encountered. Repeat until a
satisfactory setting is achieved.
B07 VALVE -
The adjuster acts to
control the rate of change between
high and low position. Turn the valve
clockwise to slow down the rate and
anticlockwise to increase the rate of
change.
SETTING LOW FLAME RATE
HIGH/LOW BURNER
(MB-ZRDLE VALVES ONLY)
Low flame gas rate is achieved by
adjusting the low gas setting of the
two position solenoid valve on the gas
MultiBloc.
Turn the low gas rate adjusting ring
on the gas MultiBloc to achieve low
flame throughput (refer to Gas
Controls and Adjustments). Care
must be taken so as not to exceed
the turndown ratio for the burner
model being commissioned.
AIR PRESSURE SWITCH
Located on the right side of the
burner casing viewed from the rear,
it is required to prove adequate air
flow throughout the burner operating
cycle. Flow failure at any stage fol-
lowing the first few seconds of pre-
purge will lockout the burner
To set the Air Pressure Switch :-
Switch off the electrical supply to the
burner.
Remove the air pressure switch
cover. Fit a manometer to the pres-
sure switch to check the actual air
pressure against the pressure switch
dial setting.
Switch on the electrical supply and
allow two stage burners to establish
low flame and single stage burners
to establish main flame.
Slowly turn the adjusting dial clock-
wise until the flame is extinguished.
The burner will go to lockout.
Turn the dial one division
anticlockwise and reset burner
lockout. The burner will then continue
through its cycle until either the start
rate flame is established or the burner
goes to its lockout position.
If the burner goes to lockout repeat
the procedure once per burner cycle
until the start rate flame is
established.
Allow the burner to cycle to low flame
(two stage) and main flame (single
stage) and then turn the adjusting dial
a further two divisions anticlockwise.
Switch off the electrical supply to the
burner, replace the air pressure
switch cover and remove the
manometer.
CHECK FLAME SIGNAL
With the burner isolated, connect in
series with the ionisation probe and
the gas burner control a DC
Ammeter. Switch on the burner.
Once the flame is established, the
microammeter will record the signal
strength. (Check high and low flame
if applicable). A minimum reading of
1.5µA will give reliable operating
conditions.
Readings below this figure may arise
from poor burner adjustment. Check
and reset if found to be necessary or
refer to the section in
Fault Finding
.
Switch off the power to the burner,
remove the microammeter, and
reconnect the ionisation probe.
Check that all covers to components
and locking devices are properly
secured.
Check that the appliance control
instruments are set to safe limits.
Commissioning is now complete.
SG10100501
