Bulletin H-IM-71A
Part No. 4346B001
August 2002
(Replaces H-IM-71, August 1996)
Air Handler Unit
Installation & Operations Manual
TABLE OF CONTENTS
Coil Stacking ........................................................................................ 5
Condensate Drain Traps ....................................................................... 4
Direct Expansion Coils ......................................................................... 3
Filter Quantities.................................................................................... 8
Freezing Temperatures ........................................................................ 6
Inspection ............................................................................................ 2
Installation ........................................................................................... 2
Internal Isolation.................................................................................. 4
Maintenance ........................................................................................ 4
Motors & Drives ................................................................................... 2
Replacement Parts ............................................................................... 8
Section Assembly................................................................................. 5
Shipment of Sections........................................................................... 7
Start-up................................................................................................ 4
Steam Coils........................................................................................... 2, 3
Water Coils ........................................................................................... 3
Weights................................................................................................ 7
When two or more steam coils are furnished in a unit,
provide separate traps for each coil. Size traps with
ample capacity using the maximum heating load and
service factor recommended b y the trap manufacturer.
When the system is started up the damper should remain
closed for approximately ten minutes after the steam
valve is opened.
Properly locate all temperature sensing elements at a
point of true average air mixture temperature.
Select control valves in accordance with the
recommendations of the control manufacturer using
actual heating loads.
Refer to “Typical Steam Coil Piping Diagrams” for
controls positioning and piping configuration.
Install suitable strainer ahead of all automatic valves and
traps to catch dirt and scale. Provide adequate air vents
to expel air and other non-condensable.
When face and bypass dampers are used, it is good
practice to install on the coil a valve which closes as
the face damper closes to prevent over heating due to
damper leakage or heat picked up by the air wiping the
exposed coil face.
Control valves used for Type “J”, “NFS”, “RA” and
“NFD” coils must be gradual acting modulating type with
veeport.
Water Piping
Where a control valve is used for Type “S” or “R” coils
and when the entering air temperature is below 35ºF.,
use a two position valve. Locate control element in the
entering air stream so that valve will remain open with
a minimum of five pounds steam pressure when the
entering air temperature is below 35ºF.
All piping must be supported independent coils.
Swing joints or flexible fittings must be provided to absorb
expansion and contraction strains. Rigid piping may also
reduce effectiveness of vibration isolators.
Typical Steam Coil Piping
The water supply should always be connected to the
bottom inlet of the coil. The coil connections are identified
with stickers.
Low Pressure Open Gravity Return System
Steam Main
Water coils , 3 through 10 rows, are supplied with a vent
and drain connection (1/4” MPT) which extends through
the unit casing.
Gate Valve
Strainer
Open Vent
Control Valve
Union
For protection of coils exposed to freezing temperatures,
refer to page 6.
Vacuum Breaker
1/2”-15” Check Valve
Coils must be adequately vented in order to prevent air
binding.
Gate Valve
12” Minimum
Union
Combination Float
and
Direct Expansion
Union
Strainer
Dirt Pocket
Thermostatic Trap
Both the liquid distributor and the suction line extend
through the casting.
Return Main
High Pressure System
The expansion valve utilized must be of the external
equalizer tube type. The expansion valve bulb must be
located on the suction line between the coil and the 1/4”
external equalizer tube. Never locate the bulb in a trap.
Steam Main
Gate Valve
Strainer
Control Valve
All refrigerant piping practices used should be in
accordance with local codes and latest ANSI Standard
B9 Safety Code. Hard drawn type “L” or “K” copper tubing
should be used. Soft tubing where bending is required
may be used provided it is protected in accordance with
local code restrictions.
Union
Vacuum Breaker
1/2”-15” Check Valve
Gate Valve
Good Practice should be followed as to pulling adequate
vacuum, tubes cleaned of foreign material, etc.
Union
12” Minimum
Float or
Bucket Trap
Union
Strainer
Dirt Pocket
Return Main
3
Start-Up
Condensate Drain Traps
Make sure all bolts and screws are tight.
The condensate drain trap piping must be properly
designed to insure the removal of condensate. Incorrect
trapping can hold water in pan causing overflow. On
blow-thru units, particular, system air can escape down
the drain with incorrect trapping.
Remove tagged shipping tie-down bolts and spacers
from the fan and motor assembly before start-up.
(Internally isolated units only.)
Check the sheaves to see if they are alignment and
make suer the set screws are tight. Make sure that
the dimension across the top is equal on all grooves,
otherwise excessive belt wear will result.
Condensate Drain Trap
(Air Seal)
Check for proper rotation of the blower pulley. Three
phase motor rotation can be reversed by exchanging
two of the three leads at the motor starter. The rotation
of single phase motors can be reversed by exchanging
leads inside the motor junction box. (See motor wiring
diagram.)
1 1/4” Pipe Drain
Check the amperage draw of the motor. This should not
exceed the nameplate amps shown on the motor serial
plate.
(a) On draw-thru units (A) shall be equal to or
greater the coils section’s negative pressure at
operating conditions.
After approximately two weeks of operation, the belts
will have nearly acquired their permanent stretch. After
this interval, the belt tension should be checked again
and proper adjustment made.
(b) On blow-thru units (A) can be as small as 1” but
(B) must equal or exceed the total static pressure
in the coil section.
Maintenance
Internally Isolated Units
The belt tension should be checked at three month
intervals.
Sizes 03-41 which have optional internal spring isolation
have four hold-down shipping braces. Remove the 1/2”
bolt between each shipping brace and the motor base,
then loosen the bolt to the frame and slide the brace to
the end of the slot so that the brace is 5/8” from motor
support base. Re-tighten the bolt so that the shipping
brace acts as a snubber on fan start up.
The fan shaft bearings on Sizes 03, 06, 08, 10, and
12 with low pressure forward curved fans have lifetime
lubricated bearings. All other units have ball bearings
which can be relubricated. These bearings mounted
inside the fan section have extended lubrication lines
which are mounted on the outside of the fan panels.
The suggested greasing intervals indicated in a sticker
attached to the unit.
It is recommended that bearings be lubricated with a
high quality lithium grease at intervals indicated on
sticker attached to the unit.
Instructions are included on the motor nameplate for
lubricating the motor bearings.
The filter should be periodically inspected and replaced
or cleaned when necessary. Dirt filters reduce the sir
flow which reduces the capacity of the system.
Do not operate system without filters.
4
Typical ‘Accessory-to-Coil-Section’
and ‘Accessory-to-Accessory’ Attaching Method
5
have anti-freeze added to it. The most positive way to
assure the mixing of the anti-freeze is to make a run-
around loop with a circulating pump.
Water Coils Exposed
to Freezing Temperature
Water coils exposed to freezing temperatures must be
protected from freeze-up by either adding anti-freeze
solution to coils or proper draining of the coils.
1. Open all connections and drain the coil as
thoroughly as possible.
2. The anti-freeze solution should be added to the
coil and circulated through the coil until the
solution is thoroughly mixed and all air is purged
from the coil. The air vent should be opened
during the filling operation and cracked during the
pumping operation to accomplish this. When
the solution has circulated for 15-20 minutes,
the concentration of the solution should be
checked with suitable hydrometer. If the
concentration is low, add more glycol and
operate the pump again. A typical piping diagram
is shown in Figure 2.
The coils are circuited so that there are no trapped
circuits. However, because of the serpentine nature of
the circuiting, it is almost impossible to adequately drain
the coils by gravity alone. Particularly on longer coils,
even a fraction of a degree deviation from a horizontal
plane can lead to water being trapped within the
serpentine.
Water that failed to drain from a single tube,
or even part of a tube, can cause the tube to
rapture upon freezing.
3. The anti-freeze solution may then be left in
the coils or drained and used to flush another
coil. The concentration must be checked for each
coil flushed.
Draining Coils Using Supplemental
Air Blower
Ideally, a blower capable of delivering 150 CFM of air
at approximately 40-50 inches of water or more should
be used. Some small air compressors, while delivering
higher pressures, probably will not deliver sufficient
volume of air and this is equally as important.
The adding of anti-freeze to a system exposed to
freezing conditions may be necessary if the system
must be operation at a moment’s notice. This affects
the chiller and coil performance and must be taken into
consideration when selection the components.
1. Drain the coils by gravity after opening the
supply, return, vent and drain connection.
Note: Most anti-freeze solution will be furnished with
a chart of concentration at freezing point. It is also
important to be certain that the anti-freeze solution
used is not corrosive to the tubing.
2. Connect the blower to large connection that
is at the greatest elevation. The small vent or
drain connection on the header to which the
blower is connected should be closed.
Refer to Figure 1 for typical hook -up during the
blow-out operation.
It is helpful to tap the coil causing along the
length of the coil during the draining process.
The blower should be operated until no moisture
can be detected leaving the coil. Then, shut the
blower off and permit the coil to stand for a few
minutes. This will permit the moisture that has
adhered to the walls to accumulate. Then the
blowing out operation should be repeated.
Ideally, the coil should be permitted to stand
twenty-four (24) hours and blown out again.
3. Leave all connections open until coil is put into
operation.
Installation of Anti-Freeze Solution
A second way to prevent a coil freeze-up is to add an
anti-freeze to the coil, such as industry inhibited glycol.
The coil should be valved off so that only the coil would
6
Air Handler Component
Section
Unit Size
03 06 08 10 12 14 18 20 26 34 41 50 65 75
Model ID Description Fan
S
S
L
L
V
HD
HD
FO
FO
Short
Short
Long
Long
Vertical
FC
AF
FC
AF
FC
290 430 500 550 650 790 816 836 968 1188 1386
946 1177 1518 1782 2700 3300 4496
318 450 553 600 732 988 1033 1067 1221 1474 1672
1177 1430 1793 2057 2850 3480 4690
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
296 387 482 535 615 860 1004 1111 1254 1628 1881
170 280 312 360 450 510 564 605 693 902 1078
–
–
–
–
–
–
Heating Duty FC
Heating Duty AF
Fan Only
Fan Only
–
162 266 296 342 428 485 536 575 658 857 1024
–
–
–
–
–
–
715 891 1221 1474 2600 3200 3359
FC
AF
–
679 846 1160 1400 2470 3040 3191
–
–
–
–
–
83
–
95
–
99 104 106 108 115 160 185 255 315 384
–
–
Flat -TA & Pleated 2”
Flat -Permanent 2”
Flat -Pleated 4”
60
66
75
73
79
88
89 101 106 114 126 135 165 240 275 390 460 560
98 110 119 124 126 127 130 185 210 298 351 428
High Capacity -TA & Pleated
High Capacity -Permanent
High Efficiency- 21” Section
High Efficiency- 28” Section
High Efficiency- 44” Section
Economizer
Combination Filter & Economizer
Internal Face and Bypass
External Face and Bypass
S Auxiliary Coil Module
L Auxiliary Coil Module
Electric Heater
149 168 187 206 215 224 230 234 244 260 290 360 440 535
155 176 196 216 225 234 240 244 254 365 450 520 650 790
82
95 112 133 133 153 175 180 194 235 248 269 330 359
103 121 143 170 170 196 225 224 246 296 318 345 425 463
127 150 173 201 201 230 264 274 299 358 380 412 516 552
174 195 216 224 236 247 254 260 300 430 550 680 800 975
323 363 403 430 451 471 484 494 544 690 840 1040 1240 1510
52
57
68
75
79 100 115 138 148 155 180 260 350 420 520 634
87 110 128 155 166 175 200 286 385 462 650 793
129 164 204 208 223 306 280 261 310 331 362 515 640 1305
157 184 257 258 305 504 497 492 563 617 648 665 820 1499
223 356 454 550 670 774 954 1104 1434 1760 2118 2481 3143 3599
1
2
3
4
6
8
Row
Row
Row
Row
36
50
56
70
80
94 106 110 112 144 195 239 339 406 538
80 101 120 143 164 169 173 228 318 396 562 673 891
5/8” Tube
(Type 5)
10 FPI
64 106 134 161 195 223 231 236 314 444 557 737 936 1168
78 132 168 202 246 282 292 299 398 569 718 913 1199 1445
Row 109 187 240 290 353 408 422 432 578 830 1052 1278 1677 2017
Row 141 242 311 379 461 534 552 565 760 1092 1385 1638 2154 2589
10 Row 172 297 383 467 569 659 682 699 942 1355 1718 2194 2893 3478
(Coil weight include the weight of water when filled)
To Estimate Weights for Other Coils
TA = Throw away type filters
AF = Airfoil Fan
FC = Forward Curved Fan
For 1/2” Tube (Type A):
For Small Coil:
For 14 FPI:
Multiply Type 5 Coil Weight by-
Multiply Large Coil Weight by-
Multiply 10 FPI Coil weight by-
Multiply 10 FPI Coil weight by-
Multiply 10 FPI Coil weight by-
Multiply 10 FPI Coil weight by-
0.800
0.823
1.121
1.065
0.935
0.915
For 12 FPI:
For 8 FPI:
For 6 FPI:
Air Handler Motor and Drive
Motor Horsepower, 1800 RPM
7.5 10 15 20 25 30 40 50 60 75
55 65 86 105 172 193 253 286 348 400 529 600 720 828
Weight in pounds
Motor Open Single Speed Motor
1
1.5-2
3
5
and
Totally Enclosed Fan Cooled (TEFC)
High Efficiency Open Single Speed
56 71 88 104 178 194 275 336 411 461 624 670
67 74 114 127 209 216 341 384 396 427 621 623
–
–
–
–
–
–
Drive
Weight Open 2 Speed, 2 Winding
71 97 115 160 291 267 368 356 366
–
–
–
T – Frame Size
143 145 182 184 213 215 254 256 284 286 324 326 364 365
Central Station Air Handler, Shipment of Assemblies - Basic Unit
Horizontal Style Units, fan, coil, flat filter section Vertical Style Units, fan, coil, flat filter section
These diagram show
typical shipments.
Some set-ups may
vary with certain units.
Consult the factory if
you require a specific
assembly shipped in a
special way.
We ship high capacity
and high efficiency filter
sections, economizers,
dampers, and electric
heat sections separately.
S, L, FO,
HD Sizes
03 – 18
FS
CS
V Sizes
03 – 18
FS
CS
S, L, FO,
HD Sizes
20 – 75
V Sizes
20 – 41
7
Quantity and Dimensions of Filters for:
Flat Filter Section
Filter
Air Handler Unit Size
03 06 08 10 12 14 18 20 26 34 41 50 65 75
Filter
Dimensions
2” x 16” x 20”
2” x 20” x 20”
2” x 16” x 25”
2” x 20” x 25”
Dimensions
2” x 16” x 20”
2” x 20” x 20”
2” x 16” x 25”
2” x 20” x 25”
1
1
–
–
–
–
–
2
2
–
2
–
–
–
4
–
3
3
–
–
1
1
2
2
2
2
2
2
6
4
–
–
4
8
–
–
–
–
4
8
6
12
–
7
–
14
–
8
20
–
4
10
4
–
–
10
High Capacity Filter Sections
2
2
–
–
–
–
–
4
–
–
6
–
–
–
2
4
–
–
8
–
–
–
4
4
–
–
6
4
–
–
4
6
–
–
2
10
4
20
–
–
–
4
20
–
–
–
30
–
–
12
30
–
–
14
35
2” x 16” x 20”
2” x 20” x 20”
2” x 16” x 25”
2” x 20” x 25”
2” x 16” x 20”
2” x 20” x 20”
2” x 16” x 25”
2” x 20” x 25”
–
High Efficiency Filter Sections
1
1
2
–
2
2
2
3
2
3
3
3
6
–
4
4
5
5
10
–
10
5
15
–
15
3
20
4
24” x 24”
12” x 24”
24” x 24”
12” x 24”
Replacement Parts- Note: Confirm the shaft Diameter, when Ordering Parts.
03-12, Forward Curved
Unit Size, Fan Diameter, Type
Shaft
Diameter
Bearing
Part No.
Bearing
Type
Shaft
Part No.
Blower
Assembly
03 FC
9”
9”
Low Pressure
3/4”
1”
1”
1 3/16”
1”
1 3/16”
1”
1 3/16”
1”
1 3/16”
4215V
4352N
4350N
4353N
4350N
4353N
4350N
4353N
4350N
4353N
Cartridge
Pillow Block
Cartridge
Pillow Block
Cartridge
Pillow Block
Cartridge
Pillow Block
Cartridge
Pillow Block
4317Z
4343N
4318Z
4344N
4319Z
4345N
4320Z
4346N
4320Z
4346N
4317M
4322M
4318M
4323M
4319M
4324M
4320M
4325M
4320M
4325M
03 FC
06 FC
06 FC
08 FC
08 FC
10 FC
10 FC
12 FC
12 FC
Med Pressure
Low Pressure
Med Pressure
Low Pressure
Med Pressure
Low Pressure
Med Pressure
Low Pressure
Med Pressure
12”
12”
15”
15”
18”
18”
18”
18”
Note: For sizes 03-12, it is less expensive to replace the blower assembly than to replace the blower wheel. Blower assembly also includes bearings and shaft
14-41, Forward Curved
Unit size, Fan Diameter, Type
Shaft
Diameter
Pillow Block
Bearing
Shaft
Wheel
Blower
Wheel
Blower
Cut-Off
14 FC
20”
20”
20”
20”
22”
22”
25”
30”
Low Pressure
1 3/16”
1 3/16”
1 3/16”
1 3/16”
1 7/16”
1 7/16”
1 11/16”
1 15/16”
4353N
4353N
4353N
4353N
5562N
5562N
5563N
5564N
4342N
4342N
4342N
4342N
4522R
4522R
4525R
4500S
5154E
5154E
5154E
5154E
5153E
5153E
5179D
5178D
Part of Housing
Part of Housing
Part of Housing
Part of Housing
4418T
14 FC
18 FC
18 FC
20FC
26 FC
34 FC
41 FC
Med Pressure
Low Pressure
Med Pressure
Med Pressure
Med Pressure
Med Pressure
Med Pressure
4418T
4419T
4421T
Note: For sizes 14-41 Forward Curved Fans, it is less expensive to replace the blower wheel than to replace the blower assembly.
26-75, Air Foils
Unit size, Fan Diameter, Type
Shaft
Diameter
Pillow Block
Bearing
Air Foil Note:
20 AF
18 1/4”
18 1/4”
24 1/2”
30”
32 3/8”
39 3/8”
39 3/8”
Med Pressure
1 7/16”
1 7/16”
1 15/16”
2 3/16”
2 7/16”
2 11/16”
2 11/16”
5562N
5562N
5564N
5521T
5597T
5875E
5875E
For sizes 41-75 Air Foils, for parts other than
bearing replacement, Contact the Factory.
Call the parts department, 800-686-7278,
with air handler model number, and discharge
arrangement. Heatcraft Refrigeration Products
can then advise the correct blower assembly
description for you.
26 AF
34 AF
41 AF
50 AF
65 AF
75 AF
Med Pressure
Med Pressure
Med Pressure
Med Pressure
Med Pressure
Med Pressure
Visit our website at www.heatcraftrpd.com for technical literature online.
Since product improvement is a continuing effort, we reserve the right to make changes
in specifications without notice.
Heatcraft Refrigeration Products LLC
2175 West Park Place Blvd. • Stone Mountain, GA 30087
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