Info 140
11/4/03
ECLIPSE AIR HEAT BURNERS
Series “AH”, “DAH”, “TAH” & “CAH”
U.S. Reissue Pat. No. 26,244 Canadian Pat. No. 743,782
AH, Front View
Data 140-1
AH, Back View
Data 140-1
TAH
Data 140-3
CAH
Data 140-4
DAH, Blower Down
Data 140-2
WARNING
The burners covered in this Guide are designed to
mix fuel with air and burn the resulting mixture. All
fuel burning devices are capable of producing explo-
sions and fires when improperly applied, installed,
adjusted, controlled, or maintained. This Guide will
provide information for using these burners for their
limited design purpose. Do not deviate from any in-
structions or application limits in this Guide without
written advice from the Eclipse Combustion Division
in Rockford, Illinois. Read this entire Guide before at-
tempting to light burners. If you do not understand
any part of the information in this Guide, contact your
local Eclipse representative or Eclipse Combustion
before proceeding further.
Specifications
Input:
1,000,000 Btu/hr. per lineal foot (962 kW/m).
Fuels:
Natural gas or 100% propane vapor. Call Eclipse for information on using other fu-
els.
Gas Turndown:
Pilot Input:
40:1
Approximately 25,000 Btu/hr. (7.3 kW)
Gas Inlet Pressure:
800,000 Btu/hr/ft. (769 kW/m):
Nat. Gas: 2.2" w.c.
Propane: 0.9" w.c.
5.5 mbar
2.2 mbar
1,000,000 Btu/hr/ft. (962 kW/m):
Nat. Gas: 3.5" w.c.
Propane: 1.3" w.c.
8.7 mbar
3.2 mbar
Gas pressure shown is a differential measured between the gas inlet and a tap on
the duct wall 10" to 20" (254 to 508 mm) downstream of the burner.
Ambient Temp. Limits*:
–40°to +104° F
–40° to +40° C
815° C
Downstream Temp. Limits: 1500° F
Flame Length**:
800,000 Btu/hr. (769 kW/m):
1,000,000 Btu/hr. (962 kW/m):
28"
46"
0.71 m
1.17 m
Piloting:
Integral spark-ignited pilot; ignition plug included.
Flame Monitoring:
Flame rod supplied. UV scanner adaptors are available. For UV scanners, Eclipse
recommends a flame monitoring system that terminates the ignition spark and
proves the pilot flame without spark prior to opening the main gas valves.
CGA requires two flame rods on burners over 36" long (914 mm). Use a flame
monitoring endplate (see Data 140-6) to mount a second flame rod on the end op-
posite the gas inlet.
Motor:
Standard: 230/460/3/60 TEFC. Other motors can be supplied.
Materials:
Emissions:
All portions of the burner exposed to flame are cast iron or #321 stainless steel.
Emissions performance depends not only on the burner,
but also other factors such as chamber temperature, chamber design, and heat load-
ing. For estimates of emissions performance in your application, call Eclipse.
Packaging Options:
Models:
Available with complete valve trains and control systems. AH burners and systems
can be supplied mounted on duct sections as specified by the customer. Call Eclipse
for information on custom packaged systems.
Model Description
Data Sheet
AH
DAH
TAH
CAH
Line-shape, blower mounted on rear
Data 140-1
Data 140-2
Data 140-3
Data 140-4
Line-shape, blower mounted on bottom
“I”-shape, blower mounted on rear
Cross-shape, blower mounted on rear
Related Information:
Blower and motor specifications
Data 140-5
* Based on blower motor limitations.
** Based on parallel air flow. If mounted in a cross flow, then flame will be shorter.
CAUTION: It is dangerous to use any fuel burning equipment unless it is equipped with suitable flame sensing de-
vices and automatic fuel shut-off valves. Eclipse can supply such equipment or information on alternate sources.
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Eclipse AirHeat v1.0 - Installation Guide No. 140, 11/4/03
2.0 Control System Requirements
Turndown Method
Input is normally controlled by a motorized butterfly valve in the gas line to the
burner.
Regulator Loading Lines
Connect the top diaphragm chambers of the main gas and pilot gas regulators to the
duct approximately 10" downstream of the burner. This will allow the regulators to
maintain a constant supply pressure to the burner regardless of varying pressures in
the duct.
Piloting
Pilot gas flow is adjusted as shown in Figure 6.
Ignition voltage should be 6000 VAC.
Ignition
Check Valve
See Figure 3. At high fire, the gas pressure at the burner inlet is higher than the air pressure, and
the check valve is closed. At low fire, gas pressure falls below the air pressure, and the check
valve opens, permitting a small amount of air to mix with the gas. This premix at low fire stabilizes
the flame and helps distribute the flame evenly down the length of the burner.
w
Do not install any valve or controlling device in the gas line between the
burner and the check valve tee, Figure 3. Because this section of the gas
line carries a partial pemix at low fire, it is possible under unusual condi-
tions for the flame to travel back through the pipe to the tee. Devices in-
stalled in this section may be damaged and may melt, releasing gas to the
atmosphere and causing fires or explosions.
Warning
Pressure Switch Connection See Figure 4 for typical connection of combustion air and circulating fan limit
switches.
Limit Controls &Safety Equipment Limit controls and safety equipment should comply with current NFPA Stan-
dards* 86 and 86C, and all applicable local codes and/or standards.
*Available from:
National Fire Protection Association
Batterymarch Park
American National Standard Inst.
1430 Broadway
Quincy, MA 02269
New York, New York 10018
Figure 3–Check Valve Operation
Figure 4—Pressure Switch Location
Blower
Pressure Switch
WARNING!
Do Not Install Any Valves Here!
See Section 2.0
P
Tube at
Blower Inlet
Burner Air Tap
See Figure 7
Lo
Hi
Tee
Process Air
Gas Inlet
Manifold
P
Check Valve Opens When
Gas Inlet Pressure Is at Low Fire
Tube Points
Downstream
Tube Points
Upstream
Hi
Lo
Circulating Air
Pressure Switch
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Eclipse AirHeat v1.0 - Installation Guide No. 140, 11/4/03
Figure 5–Mounting & Duct Lengths
Sealed
In-Duct
Slot-Fired
Duct Press: +0.2" to –0.5" w.c.
+0.5 to –1.2 mbar
Duct Press: 0" to –0.5" w.c.
0 to –1.2 mbar
Min./Max. Velocity: 500 to 6000 fpm
2.54 to 30.48 m/s
Optimum Velocity:1000 to 4000 fpm
5.08 to 20.32 m/s
Min./Max. Velocity: 500 to 1200 fpm
Min./Max. Velocity: 500 to 1200 fpm
2.54 to 6.10 m/s
2.54 to 6.10 m/s
• Provide at least 3" (76 mm) clear-
ance between burner and top, bot-
tom and sides of the duct.
• Profile plates are not required for
good burner operation, but uni-
form velocity must be maintained
for full length of burner. If velocity
is not uniform, profile plates can
be used to correct this condition.
Min./Max. Velocity: 500 to 1200 fpm
Min./Max. Velocity: 500 to 1200 fpm
2.54 to 6.10 m/s
2.54 to 6.10 m/s
Guidelines for All Mounting Arrangements
• Center the burner in the duct.
• Allow a minimum of 46" (1168 mm) from burner to nearest point
of possible flame impingement at an input of 1,000,000 Btu/hr.
(962 kW/m).
Min./Max. Velocity: 500 to 6000 fpm
2.54 to 30.48 m/s
• On burners longer than 36" (914 mm), use a hanger or a pedes-
tal to support the blower and motor.
Optimum Velocity:1000 to 4000 fpm
5.08 to 20.32 m/s
Duct Lengths
Minimum Distance Before Transition
Rectangular Ducts: One Height or Width, Whichever is Greater
Round Ducts: One Diameter
7.5°
Maximum
Air Flow
AH
Burner
Minimum Distance Before
Possible Flame Impingement = 46"
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Eclipse AirHeat v1.0 - Installation Guide No. 140, 11/4/03
3.0 Duct Design and Burner Mounting
Duct Design
See Figure 5 for typical mounting arrangements and duct designs.
Support
The mounting flange or brackets supplied with an AH burner are capable of sup-
porting the weight of the burner and blower. The AH burner case itself is de-
signed to support the weight of the blower, so the blower does not require inde-
pendent support.
Valve Train Support
Gas Piping
Support valve trains independently of the burner.
Use flexible nipples to allow for thermal expansion of the burner.
Gas flow through the check valve must be horizontal. See Figure 3.
Check Valve Piping
Gas Piping Standards
Gas piping must comply with American National Standard entitled “National Fuel
Gas Code”* (NFPA No. 54 or ANSI Z223.1), or must be acceptable to the author-
ity having jurisdiction.
Wiring Standards
Electrical wiring must comply with the National Electric Code*, (NFPA Std. 70 or
ANSI-CI 1981), or must be acceptable to the authority having jurisdiction.
*Available from:
National Fire Protection Association
Batterymarch Park
American National Standard Inst.
1430 Broadway
Quincy, MA 02269
New York, New York 10018
4.0 Start-Up And Adjustment
Initial Settings
Adjust the linkage of the gas control valve so that when heat is called for, the
valve is 10° from fully open, and when cooling is required, the valve is approxi-
mately 5° from fully closed.
Close all manual gas cocks.
With the pilot cock handle in the closed position, remove the top screw and turn
the adjusting screw five turns out from fully closed. See Figure 6.
Start Blower
Start the combustion air blower on the burner. Check the rotation to make sure it
is correct. If not, have a qualified electrician rewire the blower for proper rotation.
Start Circulating Fan
Start the duct circulating fan.
Figure 6–Pilot Cock
Figure 7–Pressure Measurement
Handle
(Shown in
Open Position)
Top Screw
Air Pressure
Taps (2)
Gas
Pressure
Tap
Duct Tap
10" to 20"
Downstream of Burner
Adjusting Screw
(Clockwise for less pilot gas,
Counterclockwise for more pilot gas)
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Eclipse AirHeat v1.0 - Installation Guide No. 140, 11/4/03
4.0 Start-Up And Adjustment (cont’d.)
Set Air Pressure Drop
Measure the air pressure drop across the burner as shown in Figure 7.
Turn the disc on the blower air inlet until the air pressure drop is between 0.4"
w.c. minimum and 1.0" w.c. maximum. For a given input, lower air pressure
drops will produce a longer flame, and higher drops will produce a shorter flame.
Large Burners Only: Some models, such as the 640, 680, and 720 TAH burn-
ers, contain a butterfly valve in the check valve line as shown in Figure 8. On
these models, after setting the air flow as described in the previous paragraph,
measure the air pressure drop between the gas pressure tap and duct as shown
in Figure 7. Gas flow must be off. Adjust the butterfly valve to produce an air
pressure drop of 0.2" w.c.
Figure 8–Butterfly
in Check Valve Line
Start Spark
Energize the ignition spark. Do not touch
the ignition rod, ignition wire, or trans-
former while the spark is energized, or
you will get a shock.
Butterfly Valve On
640, 680 & 720
TAH Burners
Check
Valve
Set Pilot Flow
Open all pilot gas valves, including the
handle of the pilot cock, Figure 6. The pilot
should light.
Turn the pilot adjusting screw to produce a
bushy blue flame that provides a flame
monitoring signal strong enough to reliably
open the gas shut-off valves.
Set Gas Flow
Measure the gas differential pressure as
shown in Figure 7.
With the gas control valve at low fire, open
all main gas valves. The burner should
light with a stable, blue low fire flame that extends evenly down the burner
length.
Drive the control valve to high fire and adjust the gas adjusting valve to produce
a pressure drop that corresponds to the desired high fire rate, as shown in Fig. 1.
When setting high fire, be sure the flame does not impinge on anything down-
stream of the burner. To shorten the flame length for a given gas input, increase
the air pressure drop as described above.
Check All Settings
Return the burner to low fire and check to be sure that the burner remains lit with
a stable flame that extends down the burner length. Cycle the burner between
low and high fire several times, checking pressure drops and flame lengths.
5.0 Routine Maintenance
Motor Lubrication
Oil the blower motor according to the manufacturer’s instructions as printed on
the motor label.
Ignition Plug/Flame Rod
Ignition plugs and flame rods wear out over long periods of normal burner opera-
tion. Eclipse recommends that the user keep at least one of each in stock at all
times to prevent nuisance shutdowns.
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Eclipse AirHeat v1.0 - Installation Guide No. 140, 11/4/03
6.0 Trouble-Shooting
Symptom
Cause
Check
Remedy
1. Burner does not
start initially.
a) Air pressure switches
not making.
a) Check pressures in
duct at location of
switch connections.
b) Check electrical
portion of switch.
a) Change pressure
connections where
a more positive
b) Faulty pressure
switches.
pressure is present.
2. Burner kicks out
shortly after start-up.
a) Low gas pressure
switch set too high.
a) Check low pressure
switch setting.
a) Reset
3. Pilot will not ignite on
initial light-off.
a) Raw gas fed into pilot
causing carbon hair on
spark plug.
a) Check spark plug for
carbon hair; also check
gap on plug (should be
3/64" - 3/32".
a) Adjust pilot gas cock by
first screwing needle
closed, then with trans-
former powered, open
needle slowly 1/4 turn
at a time.
4. Flame failure when
burner goes to high fire.
a) Gas pressure to pilot
regulator too high.
a) Check pilot gas pressure
to regulator (should be
1 PSIG maximum).
a) Relocate pilot gas line or
use second pilot
regulator.
b) Bolts which fasten pilot
casting to burner are not
tight enough.
c) Pilot regulator not react-
ing fast enough to duct
pressure changes.
b) Check tightness of bolts.
b) Tighten bolts.
c) Clean impulse line of any
dirt particles and relocate
duct connection to trans-
mit maximum duct
pressure.
c) Check impulse line for
possible dirt clogging;
also check impulse line
duct connection to
d) Check valve stuck open.
determine if an effective
pressure is being trans-
mitted to regulator.
d) Clean check valve.
e) Too much pilot gas.
e) Reduce pilot gas flow.
a) See Remedy 4a.
5. Flame failure when main
burner returns from high
to low fire.
a) Gas pressure to pilot
regulator.
a) See Check 4a.
b) Under-gassing pilot.
b) Check pilot regulator
inlet and outlet gas
pressures; also check
pilot flame.
b) Open needle on pilot
adjusting cock slowly
1/4 turn at a time.
c) See Check 4c.
c) See Remedy 4c.
6. Main flame too large at
high fire.
a) Gas pressure too high
at burner inlet.
a) Check gas pressures.
a) Screw out on main gas
pressure regulator.
Adjust linkage on gas
control valve to hold
valve less than full open
when at high fire.
b) Combustion air pressure
too low.
b) Check air pressure
differential.
c) Check valve stuck open.
b) Open air shutter on
makeup air blower.
c) Clean check valve.
7. Main flame not
a) Air pressure
differential too high.
b) Burner not firing rated
input.
a) Check air pressure
differential between
combustion air manifold
and main duct.
b) Check gas pressure
differential.
a) Close air shutter on
makeup air blower.
b) Screw in on main gas
pressure regulator to
provide more gas.
c) Clean gas holes with #42
MTD drill. Clean air
holes with #27 MTD
drill.
extending beyond face
of burner at high fire.
c) Burner gas holes
plugged.
c) Check gas holes for dirt
or lint.
8. Main flame long and
yellow.
a) Velocity past burner
lower than 500 FPM.
b) Check valve stuck open.
a) Check velocities and
rotation of main
a) Open shutter on
makeup air blower.
b) Clean check valve.
circulating fan.
Info 140 11/4/03
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