safeguard control information supplied with the burner to
determine the specific firing sequence relating to limit
and interlock circuits.
11. Set the air damper approximately
1
/
4
" open and start
the burner. The ignition circuit will be energized after
the blower prepurge period (if supplied) has been
completed and all limit and other interlock circuits have
been closed. If the unit has a gas pilot, allow it to come
on and adjust it for proper ignition and flame signal.
For flame safeguard controls having a timer Stop/Run
test switch, place the switch in the Stop position, causing
the ignition timing sequence to stop while air and gas
pressure adjustments are being made. See page 39
for details on gas pilot ignition adjustments.
Cycle the burner several times to make certain the pilot
is operating reliably. Shut the pilot gas cock and cycle
the burner through prepurge. With the gas shut off,
the pilot valve and ignition transformer will energize,
but there will be no pilot and the unit will shut down
on safety lockout.
There should be no evidence of a flame signal reading,
nor should the main oil solenoid valve attempt to open.
12. When a Gas Pilot is used to ignite the main oil, there
will be a period of time when only the pilot will be on.
The flame scanner must first detect the pilot and then,
in a given number of seconds, the main oil solenoid
valve will be energized. For direct spark ignited oil
units, the ignition spark and main oil solenoid valve
will be energized at the same time. As soon as the
oil flame is detected by the flame scanner, the ignition
spark will be de-energized (interrupted ignition), unless
the burner is equipped with intermittent spark operation,
which keeps the spark on during the burning cycle.
13. For burners equipped with gas pilots, perform an initial
Spark Pickup Test. With the pilot gas cock closed, the
burner will go through a blower prepurge period, after
which the gas pilot ignition transformer will be energized,
although no pilot will be established. (At no time should
there be any flame signal reading, nor should the main
gas valve attempt to open.) At the end of the pilot trial
for ignition and blower purge period, the flame safeguard
control should shut the system down in a safety lockout
mode, requiring manual reset of the flame safeguard
control to restart burner. If a flame signal is detected,
verify the flame retention tab and ignition electrode are
properly positioned, per Figures 33-37.
14. If the burner is direct spark ignited, either remove the
flame scanner from its sight pipe or electrically dis-
connect the main oil solenoid valve and start the burner.
In either of the above tests, the flame safeguard control
will not detect any flame and should go into a safety
lockout mode requiring manual reset of the flame
safeguard safety lockout switch.
15. There must be no indication of oil pressure at the nozzle
until the main oil valve is programmed to open. Should
a pressure reading be obtained prior to that time, it is
an indication that the main oil valve has been mis-wired
or is leaking.
16. Restart the burner and allow normal sequencing to bring
on gas pilot ignition or the direct spark ignition. Once the
main solenoid oil valve is energized, the oil flame should
be established immediately. If not, shut the system down
and make corrections as required. Do not repeatedly
recycle the burner, such as to allow any accumulation
of unburned fuel in the combustion chamber.
17. For small On/Off burners with a simplex nozzle, adjust-
ments consist primarily of attaining correct fuel/air ratios.
Adjustments should be set to obtain11-12
1
/
2
% CO
2
and
no more than a #2 smoke (Bachrach). The burner can
usually be set to burn at a 0 smoke reading. Oil pump
pressures will be set anywhere from 200 to 300 psig.
See page 34, Table 9 for additional information.
18. Fixed Air Low Fire Start burners with simplex nozzles
require correct fuel/air ratios for high fire and should
be set with no more than a #2 smoke at high fire with
11 - 12
1
/2% CO
2
. 0 smoke should be attainable. Low
fire nozzle pressures are set to achieve smooth light
off with the air dampers fixed in the operating (high
fire) position. See page 34, Table 9 for additional
information. High fire nozzle pressures will be from
200 to 300 psig.
19. Gas On/Off System with Oil Reduced Air, Low Fire
Start RALFS
See page 18.
20. Low/High/Off or Low/High/Low modes of operation
(both having automatic air dampers) should have initial
adjustments made at the light off position. See Section
3 for mechanical operation of the specific system. After
the light off fuel/air adjustments are made (which on a
Low/High/Low oil burner is the same as the Low Fire
position), run the burner to the high fire position and
make adjustments as required for good operation.
Adjustments should provide 11 - 12
1
/
2
% CO
2
with no
more than a #2 smoke (0 smoke is usually attainable)
at high fire and 8 - 10% CO
2
with no more than a #2
smoke on low fire (0 smoke is usually attainable) for
Low/High/Low systems. For systems with two-step
pumps using simplex nozzles or internal bypass
nozzles, the oil pressures at the nozzle supply pump
gauge port will generally be from 100 to 125 psig at low
fire and 200 to 300 psig at high fire. For systems with
pumps that do not have the two-step operation and
employ the internal bypass nozzle, the nozzle supply
pump gauge port will generally be from 270 to 300 psig
at both low and high fires. The nozzle bypass line
pressure at low fire will generally be from 60 to 125 psig
and 180 to 225 psig at high fire. Tighten all linkages and
permanently mark all settings. See page 31, Table 8
and page 34, Table 9 for additional information.
21. 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.
22. See items 34 through 36 in this section for
recommended limit control and other control devices
operational checkout.
Burners designed for Full Modulation operation. After
completing procedures as appropriate in items 1-15 above
proceed with modulating adjustments as follows:
23. The modulating motor is connected by linkage to the
air inlet dampers and a fuel metering valve located in
the oil nozzle return line controls a modulated fuel input
from low to high fire. Each control point has its own multi
position arm, so that proper air/fuel ratios can be
achieved throughout the entire firing range. Initial
adjustments should be made at the low fire position (low
fuel/air flow). All Power Flame burners are factory tested
and adjusted. However, to determine that the metering
valve is, in fact, in the low fire position, observe the
pointer on the metering valve shaft. The pointer must
be pointing toward the #6 or #7 position on the dial for
North American valves, or 4
1
/2 to 9 on Hauck valves. As
the burner runs from low to high fire, it will proceed from
the low fire setting towards the 0 position on the dial
(i.e., the valve will be fully closed at high fire). Refer to
page 22, Figure 27 for linkage adjustment information
and page 22, Figure 28 for adjustment information on
the Varicam
TM
characterized fuel metering system.
C29
Rev.304
To Next Page
Loading...
