Hastings AEROFLO AFX Series Manual

Installation and Service Manual
AEROFLO
AFX SERIES
HEATERS
GAS FIRING
Notice
Read These Instructions before Installation
ISAFX-1
April 2014
Supersedes March 2012

TABLE OF CONTENTS
Page
Section I. – General Information ………………………………………… 2
A. Purpose ……………………………………………………… 2
B. Shipping ……………………………………………………… 2
C. Storage……………………………………………………….. 2
D. Optional Factory Service …………………………………… 2
E. Equipment Description …………………………………….. 2
Section II. – Installation Procedure ………………………………………. 4
A. Handling the Equipment ……………………………………. 4
B. Positioning the Unit ……………………………………….. 4
C. Location of accessories …………………………………….. 6
D. Electrical connections ………………………………………. 6
E. Piping Connections …………………………………………. 6
F. Exhaust Duct Connection ………………………………….. 9
G. Combustion Air Openings 9
H. Optional Remote Control Panel Instructions……………… 10
Section III. – Pre-Start Inspection ………………………………………… 13
A. Procedure ……………………………………………………. 13
Section IV. – Start-up ………………………………………………………. 13
A. Procedure ……………………………………………………. 13
Section V. – Maintenance Schedule and Lubrication Requirements … 18
A. Maintenance Schedule ……………………………………... 18
B. Lubrication Instructions …………………………………….. 19
Section VI. – Troubleshooting ……………………………………………... 20
A. Troubleshooting Gas-Fired Units ………………………….. 20
B. General Troubleshooting Tips ……………………………... 20
1

SECTION I. – GENERAL INFORMATION
A. PURPOSE
The purpose of this manual is to present a guide for proper installation, maintenance,
and operation of Aeroflo AFX Series heaters, and to supplement, but not to replace,
the services of qualified field service personnel to supervise the initial start-up and
adjustment of the Aeroflo unit. Persons without previous experience with large
commercial and industrial equipment should not attempt the initial adjustment and
checkout procedure which is essential before such installations may be considered as
ready for operation. This manual should be made readily available to operating
personnel as an aid in trouble-shooting and proper maintenance.
B. SHIPPING
All Aeroflo units are shipped in three sections: fan section, heating section, and
discharge section. These sections have been designed to facilitate field installation.
All options and accessories are shipped mounted and wired whenever possible within
the limitations of shipping and handling. Any wired accessories which have been
disassembled for separate shipment require no additional conduit or wire for field
reassembly. All wire leads will be tagged for ease of reconnection in the field.
Shipments are made F.O.B. Hastings, Nebraska, by truck. In either case, the unit is
securely strapped, tied, and blocked to prevent shipping damage. All shipments are
checked by an inspector before they are accepted by the carrier. Parts that are
shipped unmounted are noted on the bill of lading. These parts, where feasible, are
packaged and shipped with the units. Upon receipt of shipment, all units should be
checked against the bill of lading to insure all items have been received. The units
should be checked carefully for physical damage in the presence of the carrier’s
representative. If parts are missing or damage has occurred, a claim should be filed
immediately with the carrier.
All Aeroflo units are given a complete operations test and control circuit checkout
before shipment. A copy of the flame test report, and wiring diagram is included with
each unit shipped. If correspondence with the factory is necessary, please provide the
unit model and serial number.
C. STORAGE
If equipment is not installed at time of receipt, the equipment must be stored in
a dry environment and free of rodents.
D. EQUIPMENT DESCRIPTION
The Aeroflo heater is a rugged floor-mounted industrial grade space heater that
achieves uniform building temperature, moisture control, and maximum heating
efficiency using the principle of low velocity constant air circulation to heat large air
volumes to lower temperatures. Refer to Bulletin AFX-1 for additional details.
1. Cabinet and Frame
Rugged tubular frame and all aluminized steel cabinet surfaces are painted with
heat and corrosion resistant industrial enamel. Unit includes four side return air
screens. An expanded metal, low velocity discharge plenum with either two,
three, or four sides screened is standard.
2

2. Fans
There are two heavy-duty, 10 gauge, turbine-bladed propeller fans each with a
one-piece solid shaft and self-aligning pre-lubricated ball bearings. Fixed drives
are standard on all units. A premium efficiency open dripproof ball bearing
squirrel cage induction T-frame motor is provided as standard for all voltages.
3. Burners
Standard burner is Hi-Lo-Off
Gas (G) – Power type with pilot spark ignition and main burner pilot ignition for
use with natural, manufactured, mixed, liquefied petroleum gas or liquefied
gas/air mixture. Included in the manifold are main gas electric shut-off valve with
linkage to combustion air damper, main and pilot gas pressure regulators for
maximum inlet pressure of 1 PSIG, pilot gas-air mixer and pilot solenoid valve.
Minimum standard entering gas pressure is 4 ounces.
4. Fuel and Electric Controls
Standard components for Aeroflo AFX Series heaters include a Nema 1 control
box with electronic flame safeguard system with ignition transformer, motor
starter, control transformer, high temperature limit switch, air flow switch, and a
gas electrical control system.
5. Control System
The standard control system for Hi-Lo-Off burner operation is obtained with a two-
stage thermostat that closes in sequence on a temperature drop below setpoint.
Fan operation is continuous. A detailed sequence of operation for standard gas-
fired heaters is provided later in this manual. The thermostat is factory furnished
and wired in the inlet plenum.
The optional On-Off control system is obtained with a single pole, single throw
thermostat that closes upon a temperature drop below setpoint. Fan operation is
continuous. Thermostat is factory furnished and wired in the inlet plenum.
The optional modulating control system has an On-Off thermostat as described
above plus a modulating thermostat to control a modulating butterfly fuel valve.
Fan operation is continuous. Thermostats are factory furnished and wired in the
inlet plenum.
6. Remote Control Panel (Optional)
The optional panel is furnished with a heavy duty toggle switch and three 115 volt
signal lights as depicted in Figure 5. The switch controls the blower and the
burner. The signal lights indicate supply blower operation (white light marked
“blower”), burner operation (amber light marked “heating”), and safety lockout (red
light marked “lockout”). Remote control panel lids are 16 gauge.
Wiring box dimensions are 8” x 5” x 3-1/2” deep. All wiring is 16 AWG 16/30
standard 105 thermoplastic or equivalent, color coded per corresponding wiring
diagram.
3

SECTION II. – INSTALLATION PROCEDURE
This equipment shall be installed and wired in accordance with regulations of the National
Board of Fire Underwriters, National Electric Code, and local governing bodies. The
following recommendations are not intended to supplant any requirements of federal,
state, or local codes having jurisdiction. Authorities having jurisdiction should be consulted
before installations are made. Local codes may require additional safety controls and/or
interlocks.
A. HANDLING THE EQUIPMENT
The Aeroflo unit has been designed for rigging and handling through the use of
special lifting lug hooks installed on the top of each section, and to not attempt to use
fork lift(s) to install sections. As explained previously, the unit is designed for shipping
in three sections. The fan section, burner section, and discharge plenum section must
be reassembled in the field.
When unloading and setting the heater section, use the lifting lugs on the corners
provided or move the sections on rollers. Hooks, jacks, or chains must not be used
around the casing, exhaust fan, or main control panel. DO NOT LIFT UNIT USING
COMBUSTION CHAMBER BRACKETS.
For convenience in shipping, the discharge plenum section sits on top of the fan
section. Please note that the lifting lugs on the rear of the fan section are
manufactured so that the burner section will fit on the fan section only one way.
Figure 1 depicts a typical unit assembly.
To be properly set, the Aeroflo unit should be placed on a solid foundation and set
exactly as detailed later.
During transit, unloading, and setting of the unit, bolts and nuts may have become
loosened, particularly in the pillow block ball bearing assemblies on the fan section. It
is recommended that all nuts and set screws be tightened. Turn fan shafts by hand to
make certain that propeller fan does not rub against fan venturi, and that bearing lock
rings are tight.
Open the cover on the electrical control box located near the middle on the side of the
burner section. Box can be opened by turning main disconnect switch to the “off”
position. Inspect all wire terminals and wiring terminations to ensure that all
connections are tight.
B. POSITIONING THE UNIT
Install factory supplied gasket between fan section and heater section prior to stacking
sections on top of each other.
Locate the heater exactly level, making certain the minimum clearance is maintained
between the heater, and any combustible material. The Underwriters Laboratories
Inc., listing of the heater stipulates the following clearances: 48” from main control
panel located at the burner end, 18” at the rear, both sides and top. The exhaust
stack clearance must be 18”. See page 11 for stack details.
For convenient access for maintenance, provide 24” clearance at the right side, as
seen when facing the burner, and 36” at the rear. Position the heater, if practical, with
the left hand side (as seen from burner end) next to any adjacent wall
4

Note: Over-all final dimensions may differ from those
stated in "Dimensions" table.

C. LOCATION OF ACCESSORIES
Where applicable, standard or optional accessories will be placed inside the fan
section of the unit for shipment, and must be removed and installed by the
mechanical or electrical contractor.
D. ELECTRICAL CONNECTIONS
All wiring must comply with all applicable local, state, provincial, and national electric
codes. Since shipment of unit requires disassembly after factory flame test,
reconnection of main fan motor leads will be required in the field. Connect electrical
wires (supplied in factory furnished conduit) to secondary side of main fan motor
starters. All motor leads are tagged to facilitate rewiring in the field. See wiring
diagram provided with equipment. Complete all wiring to any optional accessories as
shown on the electrical wiring diagram as required before applying voltage to the unit.
The total amperage of the main disconnect switch, blower motor, and control circuit
transformer fusing is affected by the addition of 25% to the full load amps as required
by the National Electric Code.
Check the supply voltage before energizing the unit. The maximum voltage variations
should not exceed ± 10%. Phase voltage unbalance must not exceed 2%.
E. PIPING CONNECTIONS
All gas piping connections are not shown in this manual because of the many
manifold arrangements available due to approval code requirements and different
types of modulation. All piping must comply with “Standards of National Board of Fire
Underwriters” and all applicable local codes. Contact factory if exact piping
dimensions are required. Protective pipe caps are furnished on manifolds for
shipment from factory; these caps should be removed for installation.
Run correctly sized piping to unit. Install manual gas hand shut-off valve and gas
pressure regulator if not already installed. Please note that gas line pressure must be
as shown on specification plate when unit is operating at full input.
1. Fuel Piping – Gas models
Figure 2 presents a table of gas piping sizes for varying flow rates. A typical Hi-
Lo-Off gas piping manifold is shown in Figure 3. Gas burner connection will vary
between 1” and 3” depending on the Aeroflo model and type of gas.
On gas systems, vent pressure regulator(s) and vent valve (if included with unit)
to outside of building. With vent pipe outside, install a proper vent cap and/or
screen to prevent entrance of foreign material and plugging.
6

GAS FLOW CAPACITY (CFH)
Iron Pipe Size (IPS) Inches
Length of
Pipe
(Equiv. Ft.) 1/2 3/4 1 1-1/4 1-1/2 2 3 4 6 8
15 76 172 345 750 1220 2480 6500 13880 38700 79000
30 52 120 241 535 850 1780 4700 9700 27370 55850
45 43 99 199 435 700 1470 3900 7900 23350 45600
60 38 86 173 380 610 1290 3450 6800 19330 39500
75 77 155 345 545 1120 3000 6000 17310 35300
90 70 141 310 490 1000 2700 5500 15800 32250
105 65 131 285 450 920 2450 5100 14620 29850
120 120 270 420 860 2300 4800 13680 27920
150 109 242 380 780 2090 4350 12240 25000
180 100 225 350 720 1950 4000 11160 22800
210 92 205 320 660 1780 3700 10330 21100
240 190 300 620 1680 3490 9600 19740
270 178 285 580 1580 3250 9000 18610
300 170 270 545 1490 3000 8500 17660
450 140 226 450 1230 2500 7000 14420
600 119 192 390 1030 2130 6000 12480
A. Pressure: 1/2# or Less
GAS FLOW CAPACITY (CFH)
Iron Pipe Size (IPS) Inches
Length of
Pipe
(Equiv. Ft.) 1 1-1/4 1-1/2 2 3 4 6 8
50 244 537 832 1680 5018 8464 22472 41516
100 173 380 588 1188 3549 5986 15894 29364
150 141 310 480 970 2896 4885 12972 23965
200 122 268 416 840 2509 4232 11238 20760
250 109 240 372 751 2244 3785 10050 18567
300 99 219 339 685 2047 3454 9170 16943
400 86 189 294 594 1774 2992 7945 14679
500 77 169 263 531 1587 2677 7108 13132
1000 54 119 185 375 1121 1891 5022 9279
1500 44 97 151 309 915 1544 4101 7577
2000 38 84 131 265 793 1338 3554 6567
B. Pressure: 1/2# to 1#
Figure 2 – Gas Flow Capacity for Piping of
Different Sizes and Lengths
7

F. EXHAUST DUCT CONNECTION
Installation of exhaust stack must comply with regulations of the National Board of
Fire Underwriters and local governing bodies.
The exhaust stack, exhaust stack connector, exhaust stack support and
miscellaneous items related to the exhaust stack are to be supplied and installed by
others.
Connect the exhaust stack to the heater breeching box and run stack through roof
as shown in Figure 4. Avoid use of long horizontal exhaust pipe runs; the exhauster
fan has ample capacity for venting the heater, but cannot perform satisfactorily
against strong back drafts or excessive stack resistance.
G. COMBUSTION AIR OPENINGS
When the heaters are installed in a separate heater room with fresh air and return
air ducts running direct to the base of the heater, or when the plant is under a high
negative pressure condition, provisions should be made for an outside source of
combustion air. A conservative rule of thumb for estimating the inlet area required
is 90 square inches per 1,000,000 BTU/HR heater output. The following table lists
the recommended free area of vent opening in the outside wall for various heater
sizes.
HEATER SIZE
MBH OUTPUT
AREA OF COMBUSTION AIR
INTAKE OPENING – SQ. INCHES
CONNECTING DUCT
DIAMATER - INCHES
1000 90 11
1250 113 12
1500 135 13
1750 158 14
2000 180 14
2250 202 16
2500 225 18
2750 248 18
3000 270 19
3250 292 20
3500 315 20
4500 405 24
9

H. OPTIONAL REMOTE CONTROL PANEL INSTALLATION
1. Refer to Figure 5 for guidelines.
2. All writing must comply with applicable electric codes.
3. Align box with spirit level.
4. If box is to be surface mounted, three (3) mounting holes in back of box are
recommended, one in each top corner and one at bottom center. If mounting
holes are to be located in side of box as shown, four (4) holes are
recommended, two at top and two at bottom.
5. If wiring box is to be recessed, install so that open edge of box will be flush
with finish wall. Install optional flush mounting wall plate. Examine wiring box
and control panel for clearance before providing conduit hole(s).
6. Control panel is furnished with components wired to coded terminal strip.
Installer to connect numbered terminal blocks on remote control panel to
corresponding terminal block(s) in master control panel on unit.
7. Use proper wire sizing practices when running wires for the remote control
panel.
10

SECTION III. – PRE-START INSPECTION
A pre-start inspection is extremely important and should be completed with greatest attention
given to detail. This will insure against possible unit damage on start-up and will save valuable
analysis time in the event malfunctions occur on start-up and check-out.
A. PROCEDURE
1. Check to see that all factory installed pipe plugs have been removed.
2. Check supply voltage against unit voltage.
3. Check all electrical connections in the main control panel.
4. Check that all fuses are installed and that fuse sizing agrees with the fuse chart
affixed on the inside of the main control panel door.
5. Check to see if all gas connections are tight and that all joints have been properly
sealed.
6. Check positioning of flame rod and spark rod. Make sure the combustion air fan
is fastened securely to motor shaft.
7. Check for cracks in refractory around the blast tube. This inspection requires
close observation with the aid of a good flashlight. Even a tiny crack can cause a
positive pressure within the combustion chamber and result in faulty burner
operation.
8. Check fan supply area to insure freedom of shaft rotation and proper belt tension.
Check to see that fans are tight on shaft and turn freely without rubbing the fan
venturi. The motor and shaft should turn readily by hand pull of the belts.
Properly adjusted belts can be easily depressed about one inch. Make sure the
fan shaft pillow block bearings are tight.
9. Check fan motor to insure that pulleys are secure and drive belts are tight.
10. Check all areas for cleanliness.
SECTION IV. – START-UP
All safety and operating controls have been checked during the factory test period; however, it is
advisable to complete a similar check when first operating the unit. Before attempting any service
work, make sure all electrical switches are open and manual valves are closed.
A. PROCEDURE – Caution: Always wear proper protective gear with face shield
while operating these units.
1. Precheck:
a. The high limit should be set for 200°F. The fan control should be set at 120°F.
on high and 90°F on low. Note that fan operation is continuous and that
control circuit on high side is not required for proper system operation.
b. Recheck all set screws on motor sheave and fan blade. Check alignment of
belts and pulleys. Run fans for a few minutes and adjust motor take-up if
necessary. Motors are mounted on an adjustable base shown on Figure 6.
Do not over-tighten belts since excessive tension will reduce belt life and
13

cause excessive load on bearings. After initial start, allow the belts a few days
running time to become seated in pulley grooves, then readjust as necessary.
Do not roll belts over grooves or sheaves as this will result in permanent belt
damage.
c. Combustion air, exhaust air, and rear main fan air proving switches are factory
set for 0.2” to 0.4” w.c.
2. With the unit main control panel under lock out tag out procedure applied and with
the (first-supply) manual gas valve being closed, remove the plug from the (first)
electrical safety shutoff valve on the inlet side (in some cases a plugged tee is
installed). Open the (first-supply) manual valve to purge air from the gas line.
Caution: Use an electronic combustible gas indicator as air is purged. Do not
depend on sensing the odor of gas to determine if the gas line is purged. Refer to
NFPA-54 (2012 edition or later) on procedures for proper gas purging.
3. Close main disconnect switch.
4. Push reset button on unit programming controller.
5. The On-Off burner switch on the master control panel will operate the burner
exhauster blowers.
6. All three phase motors were properly phased during factory testing. If rotation is
reversed, interrupt main power supply and interchange any two of the incoming
power leads. Reestablish power and recheck fan operation.
7. On three phase units, the starter contacts should pull in and hold quietly without
“clatter”. If they do not operate quietly, check immediately for proper line voltage.
Even temporary low voltage at start-up will cause constant operating trouble and
must be corrected before the Aeroflo heater is placed in service.
8. Open manual hand valves. After manual valves have been opened, burner
should ignite automatically if thermostat is in control circuit.
9. The burner assembly for Aeroflo heaters generally requires readjustment of the
flame test settings for proper operation under actual field conditions. The most
accurate guides to proper burner adjustment are:
a.
WARNING: Never be within the swing radius of the access door when
making flame observations through the peephole.
Proper flame travel within the stainless steel combustion chamber differs from
the pattern usually desired for a refractory lined furnace. Never adjust the
burner to produce a short “bushy” flame concentrated in the front of the
chamber as shown in figure 7A. Such a flame concentrates heat release in
the front end of the chamber and creates a short circuit between the burner
and economizer tube section which results in high stack temperature. Figure
7B illustrates a flame that is much too long and will cause over-heating of the
rear wall. A correct flame should be fairly vigorous, free of smoky haze, and
should barely impinge on the rear wall of the chamber. Figure 7C illustrates
proper flame travel. This long steady flame provides adequate time for
complete combustion and balanced heat release to all surfaces of the
chamber. Typical draft conditions are noted in Figure 8 for firing at full rate
capacity. Adjust to field conditions when necessary.
b. Temperature and CO2, O2, CO and percentage of excess air content of the
flue gasses.
c. Proper flame signal from flame rod sensor (4-10 VDC).
14

AFX MODEL #
FULL RATED
MBH OUTPUT EXHAUSTER RPM
CHAMBER
PRESSURE
(NEG. “ W.C.)
BREECHING
PRESSURE
(NEG. “ W.C.)
248
850
1000
1250
1500
1750
2000
1640
1640
1640
1640
1875
2130
.75
.60
.55
.50
.70
.55
1.10
1.10
1.10
1.10
1.25
1.40
254
100
1250
1750
2000
1800
1800
1800
1800
1.00
.95
.70
.55
1.00
1.05
1.25
1.40
260
1250
1500
1750
2250
2500
1635
1635
1635
1635
1635
1.00
.95
.88
.70
.60
1.50
1.60
1.70
1.90
2.00
272/284
1750
2000
2250
2500
2750
3000
3250
3500
1850
1850
1850
1850
1850
1850
1850
1850
1.08
1.05
1.00
.87
.75
.65
.55
.50
1.20
1.25
1.30
1.45
1.60
1.75
1.90
2.00
360 4500 1850 .40 1.65
Note: Values shown are those obtained when firing at full rated output.
Figure 8 – Typical Draft Conditions for
Aeroflo AFX Series Heaters
17

10. Burner Start-up
Open the air louver on the air inlet to approximately the one-half open position.
Open the manual gas valve slowly, burner will ignite. Open valve until gas
pressure on the gauge is approximately 4 ounces. (See spec plate for factory
differential pressure settings. Use “U” tube manometer.) Observe flame
conditions. If gas flame has yellow or yellow tip appearance, open combustion
air louver wider until flame appears short and hard.
Adjust gas pressure regulator to hold 4 ounces gas pressure on burner while
firing with the manual gas cock in the wide open position. Read gas meter
serving burner, input should be approximately that stated on the burner name
plate. If not, readjust regulator to obtain rated input. NOTE: Check to see if
other appliances are on before reading meter.
When the gas input rate is established, air adjustments may be made. The final
air setting should produce a flue gas analysis of between 8-1/2% and 9-1/2%
CO2, 5-1/2% to 6-1/2% O2 with 0 ppm to 10 ppm of CO and 23% to 30% excess
air. Your local gas utility may aid you in making burner adjustments if you do not
have the proper instruments.
Start and stop burner several times to insure proper operation. Check for proper
functioning of high limit and operating control. Burner is now ready for normal
operation.
11. The typical sequence of operation for two-stage gas-fired units is as follows:
a. Closing fused disconnect switch (FD) will energize 115 volt control circuit
through control transformer (T2).
b. The On-Off burner switch (XB) on the master control panel will operate the
fans. Unit burner operation is controlled by two-stage thermostat (TT).
Blower motors (M1A and M1B) will operate through blower motor starters
(1MA and 1MB) if starter overloads are all operational. The bonnet fan
switch will remain in the electrical circuit after burner shutdown until blower
has cooled heat exchanger to a temperature below the setpoint of the
control.
c. After continuous flame has been established, ignition transformer and pilot
valve drop out of circuit.
d. If safety shutdown should occur upon failure to ignite pilot, failure to light the
main burner flame, or loss of flame while main burner is firing, the internal
lockout switch will trip and lockout the protectorelay.
18

COUNTERFLO / AFX FLAME TEST REPORT
Model No._________________ Configuration No.___________________ Ser. No.___________
Date: _______________ Assembled By _______________ Tested By_____________
Approvals and/or Label No. ____________________________
MOTOR OPERATING DATA
Blower Exhauster Burner
Nameplate As Read Nameplate As read Nameplate As Read
MFG.
MODEL/CAT NO.
HP
RPM
VOLT
AMP
PHASE
FAN OPERATION
Main Fan
Design Speed ____________ RPM Drive Fixed_________ Variable________
As Read____________ RPM
Exhauster
Design Speed ____________ RPM Drive Fixed_________ Variable________
As Read____________ RPM
BURNER OPERATION
MFG. HASTINGS MAXON OTHER _____________
MODEL ____________________ ________________ _______________
FUEL TYPE NG or LP
DESIGN INLET PRESSURE _____________ “ W.C./PSI AS TESTED __________ : W.C./PSI
BURNER (High Fire) OPERATING DIFF. PRESSURE (7” W.C. MAX) AS TESTED _______” W.C.
FLAME SAFETY D.C. Volt Reading (High Fire) _____________ (Low Fire) ______________
STACK TEMPERATURE _________°F COMBUSTION TEST __(Attach Comb Text Printout)_
DRAFT IN COMB CHAMBER (Hot) _______________” W.C. STACK _______________” W.C.
DIELECTRIC TEST
1-30V @ 600V for 1 Sec.
31-120V @ 1500V for 1 Sec.
121-250V @ 1800V for 1 Sec.
215-600V @ 2400V for 1 Sec.
-19-