*
See note on Page 25.
(7 - 9% CO
2
,
little or no* CO). Mark the linkage at the new
settings.
25. Increase the firing rate to the midway point. Set the fuel/air
ratios to achieve good combustion values (7-9% CO
2
, little
or no* CO). Mark the linkage as a reference point for this
new mid fire position.
26. Increase the rate to high fire position and repeat the test
done for the mid point adjustment. Results should range in
the area of 8
1
/
2
to 10% CO
2
, with little or no* CO. The me-
tering device setting and air damper openings should be
marked and noted to obtain high fire reference points.
Note that an additional point of the fire adjustment may be
obtained by modifying the regulated gas pressure deliver-
ed to the burner metering device. The burner pressure
regulator is used to obtain this adjustment and can be
used within available pressure limits to obtain optimum
firing conditions.
27. Operate the modulating lever arm on the modulating
motor through the three previously referenced points.
Minor setting modifications may be required to ensure
that the reference points are acquired.
28. Tighten (finger tight) the hex bolt to the linkage rod at
the swivel on the modulating motor driver arms and run
the motor through its full travel to ensure that the linkage
is free and that limits on the metering device and air
dampers are not exceeded.
29. Determine that the required gas input rate is being
achieved by clocking the gas flow at the gas meter.The
gas utility should be consulted to determine if any
correction factors have to be applied to the indicated
meter flow rates. Refer to page 41 for additional
combustion analysis information and to page 6 for
additional firing rate information.
30. Intermittently operate the burner until the water is warm
in the boiler, or follow specific initial firing recommen-
dations provided by the heat exchanger manufacturer.
31. Tighten all linkages and permanently mark settings.
32. Limit control check should be made as follows:
A) Permit the burner to run until the limit control settings
have been reached.
B) The burner should turn off when the set temperature
or pressure has been reached. If the burner is Low/
High/Low or Modulating, set the controls so that the
burner will go to the low fire position before the
operating limit control turns the burner off.
C) After a differential pressure or temperature drop, the
burner should restart automatically.
D) With the unit running normally, open the blow down
valve and remove water to the point below the Low
Water Cut Off Setting. The burner should turn off and
restart automatically when the proper water level is
re-established. (If a manual reset type Low Water
Cut Off is used, it will have to be reset.)
33. Set and check operation of:
A) Low and high gas pressure switches. See gas
pressure switch manufacturer’s instructions for
detailed procedures. Units with mercury switching
device must be properly leveled.
(1) For initial start up:
Once the burner’s normal operational gas
pressure has been set, adjust the low and high
gas pressure switches as follows:
(a) Low gas pressure switch. With the burner
running, slowly close the main gas train
manual shutoff cock and adjust the switch
to open its circuit when the pressure falls
below its normal value. The burner will shut
down. Open the manual gas shutoff cock to
the full open position and manually reset
the Low Gas Pressure Switch. The burner
will restart.
(b) High gas pressure switch. With the burner
running, adjust the switch to a point where
the switch opens its circuit. The burner will
shut down. Manually reset the switch and
readjust the cutout point to be made at the
normal operating pressure, but to open if
the pressure goes slightly above normal.
B) All burner and heat exchanger controls and operating
devices.
C) Blower Combustion Air Flow Switch
(1) Shut burner power off.
(2) Disconnect both wires at the air flow switch and
temporarily clip them together. Make sure that
they cannot ground against anything, since they
will be powered with 110 volts during the test.
(3) Put a continuity meter across the common and
normally open terminals on the air switch.
(4) Close the gas train checking cock.
(5) Start the blower motor. The meter should read
electrical continuity as soon as the blower starts.
(6) Disconnect the blower motor lead wire or the
wire which energizes coil of motor relay (starter),
or open the main power disconnect switch to
the burner. Within 4 to 5 seconds after the
blower motor is de-energized, the meter
should indicate an open air flow switch circuit
(no continuity).
(7) If the switch does not open in 4 to 5 seconds,
readjust accordingly. Turn the air flow switch
adjustment screw clockwise to shorten cut-off
response time, and counter-clock-wise to
lengthen cut-off response time.
(8) Turn the burner power off. Remove the shorting
clip from the two disconnected wires and let
them hang loose. (They will be powered with
110 volts, so don’t let them ground out.)
(9) Open the gas train checking cock. Turn the
burner on. With the wires disconnected, the
burner should go into a purge cycle, although
neither the ignition nor the main fuel valve
circuits will be energized. If they do energize,
there is a wiring problem. Correct as required.
(10) Turn power off. Reconnect the air flow switch
wires to the air flow switch terminals. Place
burner back into normal operation.
34. The Owner’s Operating Instructions, page 51 of this
manual, should be posted in a clearly visible location
close to the burner.
35. If the burner operation is abnormal, refer to Section 7,
Trouble Shooting Suggestions, as well as trouble
shooting information included in the flame safeguard
manufacturer’s bulletin shipped with the burner. It is
also strongly suggested that all test procedures
outlined in the flame safeguard control manufacturer’s
bulletin be conducted.
36. Complete the Burner Start Up Information and Test Data
sheets on pages 46 and 47.
C27
Rev.304
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