PVI FIREPOWERâ GAS BURNER
TYPICAL CONSTRUCTION
Figure 9-1
1. Burner housing
2. Air intake
15. Air switch
16. Door assembly *
17. Flame sensing electrode
18. Ignition electrode
19. Ignition transformer
20. On-off switch *
21. 1/4” NPT pressure port plug
22. Motor mounting plate *
23. Motor relay or starter *
24. Pressure plate
25. Primary gas ports
26. Secondary gas ports (gas spider)
29. Orifice location *
30. Electrode retaining bracket
31. Burner cover
32. Burner sight glass
33. Air shutter
34. Union
35. Flame safeguard control
36. Flame cone
37. Manual gas valve
38. Lifting eye bolt
39. Power connector
40. Manifold test port
3. Oil pump opening plug
4. Mounting flange
5. Mounting flange gasket
6. Blast tube screw
7. Blast tube
8. Nozzle assembly
9. Nozzle mount bolt
10. Air inlet cone
11. Air screen
12. Fan wheel
13. Motor, 3450 rpm CWSE rotation
14. Air nipple
27. Gas regulator
28. Gas valve
* On some models
PV500-9 04-2000
(1)
Section 9
POWER GAS BURNER START-UP (Con’t)
flame safeguard reset button. The burner should pre-
clearance). Ensure plate is seated firmly against the
gas spider and tighten the plate retaining screws.
Recheck electrode setting as to gap and position.
purge for not longer than thirty seconds. The TFM
series control will have either an MT30-4, MT30-10
or MT12-5 time card. The “30 indicated a 30-second
purge time and the “4”, “5” or “10” indicated a 4-
second, 5-second, or 10-second trial for ignition
period, commonly called TFI.
15. Replace nozzle assembly; be sure to connect the flame
and spark rod wires before installing nozzle assembly
fully into blast tube. Check to be sure connectors on
the ends of the flame and spark rod wires have a good
contact. Look for properly stripped wire ends. Be sure
connectors are firmly attached to the flame and ignition
rod ends. Insulating boots can give a false feeling of
proper seating. BE CAREFUL NOT TO MOVE
ELECTRODES. Be careful not to bump electrodes
Check fan wheel for free rotation.
When the blower motor starts, the air switch which
proves air flow should close and terminal 6 will be
powered. This starts the pre-purge timing sequence.
After purging is complete, terminal 3 or 4 on the
TFM control are energized. Terminal 3 energizes
the pilot valve and terminal 4 energizes the ignition
transformer. At this time, the pilot is established.
The VDC reading on thermometer should read a
steady 14-17 VDC for a TFM control. Each different
control will have the required flame response signal
stamped on it. This is the minimum for it to properly
operate. If the pilot fails to light during the initial
ignition period, it is probably due to air in the line.
The control will lock out. Wait one minute and push
the flame safeguard reset button to restart burner
and begin the purge cycle again.
16. Reinstall orifices in unions (if required). Reinstall burner
cover.
17. Connect a test meter to the control for reading the
flame response signal.
NOTE: Some controls read the flame signal in micro
amps and some in volts DC. The TFM series control has
two terminals marked for reading volts DC. The S89
control uses a micro amp signal for measuring flame
strength. For this control, a meter must be hooked in
series with the flame rod wire. Disconnect the leadwire
at the S89 sensor terminal. Connect the positive lead of
the meter to the quick-connect sensor terminal on the
S89 and the negative lead to the free end of the sensor
leadwire.
Now, set the pilot pressure (measured downstream
of gas valve) at the pressure shown on the tag
attached to the gas train. Next, open the main gas
valve slowly. Set manifold pressure at the pressure
shown on the tag attached to the gas train. Do not
screw the adjusting nut of the regulator in past the
point where no further increase in manifold pressure
is noted. Check the incoming pressure with the
burner running. This is recorded as inlet flow
pressure.
18. Be sure the tank is filled with water. Once the burner is
reassembled, two devices to read pressure, preferable
U-tube manometers, will be needed to read gas
pressures. Connect one to read the inlet pressure of
the burner. This is the pressure measured before all
components in the gas train. The manometer must stay
connected throughout the testing, as the inlet pressure
must be monitored during the firing of the burner.
Record static pressure. It must not exceed 14” W.C. for
burners with inputs through 3,200,000 Btu/h. For inputs
above 3,200,000 Btu/h, refer to the appliance date
plate for the correct maximum inlet pressure Pressures
above this could cause damage to the diaphragm in the
gas valve or pressure regulator.
Our standard flow pressure requirements are:
a. 5” W.C. with 8” W.C. flow on burners with inputs
through 1,600,000 Btu/h.
b. 8” W.C. with 11” W.C. flow on burners with inputs
from 2,000,000 Btu/h through 3,200,000 But/h.
c. For inputs above 3,200,000 Btu/h, refer to the tag
attached to the gas train for the correct inlet
pressures.
C. If the required manifold cannot be reached, check
the inlet pressure. It should be a minimum of that
shown above with the burner running on full input. It
is important that the incoming pressure does not fall
below these minimums or nuisance control lockouts
could occur.
19. Burners with pilot:
A. Connect the manometer to the manifold test port at
the shutoff valve closest to the burner. Turn the main
gas shutoff valve off. Set the air shutter as shown on
the tag attached to the gas train, (see Figure 9-4 and
9-5). This may not be the exact setting you end with,
but it is a good starting point. Turn the unit on using
the rocker switch on the side of the control enclosure
assembly and the toggle switch on the burner. If the
operating control switches are closed, the burner
should come on and pre-purge begin.
NOTE: Where low gas pressure is a problem, special
arrangements may have been made to fire the burner
with reduced pressure. The appliance data decal will
reflect this information.
B. If nothing happens, check the control to be sure it is
not in the tripped position and reset it by pushing
PV500-9 04-2000
(3)
Section 9
POWER GAS BURNER START-UP (Con’t)
20. Direct Spark Ignition – (DSI) Burners – No pilot:
STACK TEMPERATURES
MAX. GROSS
1. Connect a manometer to the manifold test port. Set
the air shutter as shown on the tag attached to the
gas train. This may not be the exact setting you end
up with, but it is a good starting point. Turn the unit
on using the rocker switch on the side of the control
enclosure assembly. The burner should come on
and ignition occur. If the burner fails to ignite, there
may have been air in the line. To reset the control,
turn the switch off for 60 seconds (S89 controls only)
and it should automatically reset or push the reset
button on the control. Once the burner fires, set the
manifold pressure at the valve shown on the tag
attached to the gas train. There will a tap on the
downstream side of the valve to measure pressure.
The manifold pressure must be taken downstream of
the gas valve. Check the incoming pressure with the
burner running. This is recorded as flow pressure
and must be a minimum of 8” W.C.
*MIN. NET
STACK
SERIES
STACK
PG
(Vertical Tube)
TP
550°F
300°F
TPO
TPGO
375°F
300°F
TABLE 9-1
* Net temperature is the total stack temperature, less room temperature.
22. On burners with pilots, recheck pilot to make sure its
operation has not deteriorated if adjustments are made
to the air shutter. To do this, shut off the main valve,
check the flame response signal by cycling the burner
through several lightoffs.
23. Check each operating and limit control to be sure they
function properly by lowering and raising the
temperature setting on each control, causing the burner
to cycle on and off.
21. Make final settings of the air shutter by checking the
flue gas analyzer.
NOTE: During the initial firing of the burner, smoke that
is not related to the burner will be emitted from the
heater. This is normal during “burn in” and could
possibly continue for several days.
A. The readings need to be taken from a hole in the
vent several inches above the heater vent
connection, but before draft regulator.
B. Insert draft gauge into the 1/4” test opening in the
stack. Draft in stack should read -.02 to -.06 W.C.
Adjust draft regulator, if installed.
24. Record the following information for future use:
C. When water in the tank is above 120°F°, insert CO2
tester in 1/4” test opening and take CO2 reading in
percentage. CO2 reading at this time will probably be
below optimum.
D. Gradually close the air shutter, taking CO2 reading at
each adjustment of air shutter until optimum CO2
percentage (8-10%) is reached. If CO2 percentage
decreases, open air shutter to last reading where the
greatest reading was achieved.
A. Air shutter position__________________________
B. Manifold gas pressure____________________"W.C.
C. Stack draft_____________________________"W.C.
D. CO2 reading______________________% (8%-10%)
E. CO reading__________________% (less than .03%)
F. Stack temperature:
Gross_____________________________°F
Less ambient_______________________°F
Net_______________________________°F
E. Insert CO tester in 1/4” test opening and take CO
reading. CO should not exceed .03%. A reading
greater then .03% indicates lack of air. Open air
shutter slightly and take readings until CO is within
proper range. Optimum reading is no CO.
G. Thermal efficiency_________________________%
F. If air shutter has been changed during CO test, take
a final CO2 reading.
G. Insert stack temperature gauge in 1/4” test opening
and read gross stack temperature. Temperature
should be as shown in Table 9-1. If an excessively
high gross stack temperature is recorded, check the
flue tubes for baffles. All tubes should have at least
one baffle for TURBOPOWERâ modules. Record the
length of the baffles on TURBOPOWERâ models for
future use.
H. Make sure the air shutter is locked securely in place.
PV500-9 04-2000
(4)
Section 9
REMOVAL OF THE NOZZLE ASSEMBLY
(EXCEPT “L” SERIES BURNERS)
Figure 9-2
ELECTRODE POSITIONS
“L,P,Q,R,S,T” SERIES BURNER
Figure 9-3
PV500-9 04-2000
(5)
Section 9
AIR ADJUSTMENT
FIXED AIR BURNERS
Loosen the locking screw and move the arm (B) along
the scale (C) to the position wanted and tighten the
screw. Check the air adjustment by making a flue gas
analysis.
Figure 9-4
AIR ADJUSTMENT
VARIABLE AIR BURNERS
Adjust first air shutter by loosening locking screw
and move arm (B) along scale (C) to give best
flame signal strength and most consistent light-off
with pilot pressures set. Set second shutter linkage
by installing linkage rod into ball joints of
modulating motor and air damper shaft arm. With
damper closed and modulating motor in full down
position, set ball joints secured. Observe
combustion reading through full range of
modulation. Adjust as needed to obtain proper
combustion efficiencies with carbon monoxide-free
combustion. Make all adjustments with linkage in
the low fire position. CAUTION: Do not allow the
modulating motor to push the air damper past
the full open or full closed position while
making adjustments. Damage will occur. Record
damper positions from indicator dials and hold
linkage rod in ball joint with fingers as motor
actuates to eliminate this risk. After correct damper
movement is determined, tighten ball joint screws.
Figure 9-5
BURNER MOTORS
No routine service is necessary on the blower system other than cleaning the blower wheel or oiling the motor when
necessary. Blowers using three-phase motors will run in either direction depending on the connection of the power supply.
On new installations, motor replacement or power supply disturbance, the rotation must be checked. Corrections can be
made by interchanging any 2 wires of the three-phase power supply.
NOMOGRAPH FOR DETERMINING FLUE LOSSES FROM CO2 AND FLUE TEMPERATURE FOR NATURAL GAS
(STEADY STATE EFFICIENCY CAN BE DETERMINED FROM THE FLUE LOSS)
PV500-9 04-2000
(6)
Section 9
Figure 9-6
NOTE: Nomograph is limited for use with Natural Gases with the following characteristics:
Heating Value (gross) Btu/SCF - 970-1100; Specific Gravity - 0.57-0.70; Ultimate CO2 - 11.7-12.2.
PV500-9 04-2000
(7)
Section 9
NOMOGRAPH FOR DETERMINING FLUE LOSSES FROM CO2 AND FLUE TEMPERATURE FOR L.P. GAS
(STEADY STATE EFFICIENCY CAN BE DETERMINED FROM THE FLUE LOSS)
Figure 9-7
NOTE: Nomograph is limited for use with L.P. Gas with the following characteristics:
Heating Value (gross) Btu/SCF – 2466-2542; Specific Gravity – 1.522-1.574; Ultimate CO2 – 13.73-13.82.
PV500-9 04-2000
(8)
Section 9
TROUBLESHOOTING SUGGESTIONS
GAS BURNER
1. BURNERS FAILS TO START
A. Defective On/Off or fuel transfer switch. Replace switch.
B. Control circuit has an open control contact. Check limits, low water cutoff, proof of closure switch and
others as applicable.
C. Bad fuse or switch open on incoming power source. Correct as required.
D. Motor overloads tripped. Reset and correct cause for trip out.
E. Flame safeguard control safety switch tripped out. Reset and determine cause for apparent flame
failure.
F. Loose connections or faulty wiring. Tighten all terminal screws and consult wiring diagram furnished
with the burner.
G. Flame safeguard control starting circuit blocked due to flame relay being energized. Possible defective
scanner or flame rod – replace. Possible defective amplifier – replace. Scanner actually sighting flame
due to leaking fuel valve – correct unwanted flame cause. Defective flame safeguard control – replace.
H. Defective blower motor. Repair or replace.
2. OCCASIONAL LOCKOUTS FOR NO APPARENT REASON
A. Gas pilot ignition failure. Check to see that ignition is instant and that flame signal readings are stable
and above minimum values. Use a manometer or 0 to 10" W.C. gas pressure gauge to make certain that
pressure is as recommended.
B. Loose or broken wires. Check all wire nut connections and tighten all terminal screw connections in
panel and elsewhere as appropriate.
C. With flame safeguard controls that incorporate the air flow switch in the non-recycling circuit, ensure
that when main flame lights, the air flow switch is not so critically set as to allow occasional momentary
opening of the air switch contacts.
D. Occasional low voltage supply. Have local utility correct. Make certain that the burner control circuit
transformer (if supplied) is correct for the voltage and power (VAC) being supplied.
E. Occasional low gas supply pressure. Have local utility correct.
3. BURNER MOTOR RUNS, BUT PILOT DOES NOT LIGHT
A. Gas supply to burner shut off – make sure all manual gas supply valves are open. Automatic high
pressure valve at meter such as "Sentry" type tripped shut due to high gas pressure – reset valve and
correct cause for trip out.
B. Pilot solenoid valve not opening – listen and feel for valve actuation. Solenoid valve not being powered
– check electrical circuitry. Replace coil or entire valve if coil is burned out.
C. Defective gas pilot regulator – replace.
D. Gas pressure too high or too low at pilot orifice (if supplied). Check orifice size in gas pilot assembly.
Replace if incorrect. Readjust pressure as required.
E. Defective ignition transformer – replace. Incorrect ignition electrode settings – readjust as required.
F. Defective flame safeguard control or plug in purge timing card. Replace as required.
G. Air flow switch not making circuit – check out electrically. Defective air flow switch – replace. Air switch
negative pressure sensing tube out of position – reposition if necessary.
4. BURNER MOTOR RUNS & PILOT LIGHTS, BUT MAIN GAS FLAME IS NOT ESTABLISHED
A. Main shut off or test cock closed. Check to make certain fully open.
B. Pilot flame signal reading too low to pull in flame safeguard relay. Readjust as required.
C. Defective automatic main or auxiliary gas shut off valves. Check electrical circuitry to valves. Replace
valves or correct circuitry as required.
D. Main diaphragm shut off valve opening too slowly. Adjust bleed on valve.
E. Defective flame safeguard control or plug in amplifier. Check and replace as required.
F. Butterfly valve set incorrectly on modulating burner. Readjust as required.
G. Main gas pressure regulator atmospheric vent line obstructed. Correct.
H. Defective main gas pressure regulator – replace. Misadjusted main gas pressure regulator – readjust to
meet required operational values.
PV500-9 04-2000
(9)
Section 9
TROUBLESHOOTING SUGGESTIONS
GAS BURNER (Con't)
5. CARBON MONOXIDE READINGS ON GAS FIRING
A. Flame impingement on "cold" heat transfer surfaces caused by excessive firing rate. Reduce firing rate
to correct input volume.
B. Incorrect gas/air ratios. Readjust burner to correct CO2/O2 levels, eliminating all CO formation.
6. GAS HIGH FIRE INPUT CANNOT BE ACHIEVED
A. Gas company pressure regulator or meter operating incorrectly, not allowing required gas pressure at
burner train inlet. Have gas company correct.
B. Gas cock upstream of train inlet not fully open. Check and correct.
C. Gas line obstructed. Check and correct.
D. Gas train main and/or leak test cocks not fully open. Check and correct.
E. Gas supply line between gas company regulator and burner inlet too small. Check supply pressure at
meter, determine pressure drop and increase line size as required, or raise supply pressure to
compensate for small line. Do not raise pressure so high that under static (no flow) condition the
pressure exceeds the maximum allowable pressure to the gas train components on the burner.
F. Burner gas train components sized too small for supply pressure. Increase component size as
appropriate or consult factory.
G. Automatic gas valve not opening fully due to defective operation. Replace gas valve.
H. Orifice (if supplied) too small. Replace with correct size.
I.
On modulating burner, butterfly valve not fully opened. Readjust.
J. Defective main gas pressure regulator. Replace.
K. Incorrect spring in main gas pressure regulator. Replace as required.
L. Main gas pressure regulator vent line obstructed. Check and correct.
M. Normally open vent valve (if supplied) not closing when automatic gas valves open. Check to see if
valve is fully closed when automatic valves are open. Replace vent valve, if not closing fully.
Additional troubleshooting information can be found in the Flame Safeguard Control bulletin supplied with the burner.
PV500-9 04-2000
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Section 9
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