Unitary products group LA120 User manual

INSTALLATION
MANUAL
CAUTION: READ ALL SAFETY GUIDES BEFORE YOU
BEGIN TO INSTALL YOUR UNIT.
SAVE THIS MANUAL
MODEL: LA120
(AIR COOLED)
SPLIT-SYSTEM
AIR CONDITIONER
035-18525-001-B-0203
CONTENTS
NOMENCLATURE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
GENERAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
SAFETY CONSIDERATIONS . . . . . . . . . . . . . . . . . . . . . 4
AGENCY APPROVALS . . . . . . . . . . . . . . . . . . . . . . . . . 4
INSPECTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
MAINTENANCE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
NOTES, CAUTIONS AND WARNINGS
Installer should pay particular attention to the words:
NOTE, CAUTION, and WARNING. Notes are intended to
clarify or make the installation easier. Cautions are given
to prevent equipment damage. Warnings are given to
alert installer that personal injury and/or equipment dam-
age may result if installation procedure is not handled
properly.

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TABLE OF CONTENTS
NOMENCLATURE . . . . . . . . . . . . . . . . . . . . . . . . . . .3
GENERAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
SAFETY CONSIDERATIONS . . . . . . . . . . . . . . . . . .4
RENEWAL PARTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
AGENCY APPROVALS . . . . . . . . . . . . . . . . . . . . . . .4
INSPECTION 4
INSTALLATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
LIMITATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
LOCATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
RIGGING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
CLEARANCES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
VERTICAL / HORIZONTAL INSTALLATION . . . . . . . . . . 8
DUCT CONNECTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
DRAIN CONNECTION . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
REFRIGERANT MAINS . . . . . . . . . . . . . . . . . . . . . . . . . . 9
POWER AND CONTROL WIRING . . . . . . . . . . . . . . . . . 10
SUPPLY AIR BLOWER ADJUSTMENT . . . . . . . . . . . . . 11
ACCESSORIES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
MAINTENANCE . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
EVAPORATOR COIL . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
FILTERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
DRAIN PAN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
LUBRICATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
BELTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
LIST OF FIGURES
Fig. # Pg. #
1. UNIT SUSPENSION MOUNTING LA120 (HORIZONTAL
APPLICATIONS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2. VERTICAL AND HORIZONTAL APPLICATION . . . . . . 8
3. VERTICAL AND HORIZONTAL APPLICATION . . . . . . 8
4. SUPPLY AIR PLENUM ACCESSORY . . . . . . . . . . . . . 9
5. BASE ACCESSORY (VERTICAL ONLY) . . . . . . . . . . . 9
6. RECOMMENDED DRAIN PIPING . . . . . . . . . . . . . . . 10
7. RETURN AIR GRILLE ACCESSORY (VERTICAL) . . 10
Fig. # Pg. #
8. FIELD WIRING DIAGRAMS FOR POWER SUPPLY . 12
9. FIELD WIRING DIAGRAM COOLING
(COOLING ONLY) . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
10. TYPICAL MOTOR MOUNTING ASSEMBLY . . . . . . . 13
11. HOLE LOCATIONS FOR PRESSURE DROP
READINGS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
12. PRESSURE DROP ACROSS A DRY
EVAPORATOR COIL VS. SUPPLY AIR CFM . . . . . . 14
13. BLOWER PERFORMANCE CURVE . . . . . . . . . . . . . 15
14. UNIT DIMENSIONS AND CLEARANCES . . . . . . . . . 16
LIST OF TABLES
Tbl. # Pg. #
1. PHYSICAL DATA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2. APPLICATION LIMITATIONS . . . . . . . . . . . . . . . . . . . 5
3. LA120 UNIT SUSPENSION WEIGHTS (LBS) . . . . . . . 7
4. ELECTRIC HEATER DIMENSIONS FA120 . . . . . . . . . 9
5. ELECTRICAL DATA . . . . . . . . . . . . . . . . . . . . . . . . . 11
6. SUPPLY AIR BLOWER MOTOR PULLY
ADJUSTMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
7. BLOWER MOTOR AND DRIVE DATA . . . . . . . . . . . 14
8. SUPPLY AIR BLOWER PERFORMANCE 1, 2 . . . . . 15
9. ACCESSORY STATIC RESISTANCE (IWG)
(TO BE INCLUDED WITH DUCT SYSTEM
STATIC RESISTANCE) . . . . . . . . . . . . . . . . . . . . . . 16

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NOMENCLATURE
YORK SPLIT INDOOR PRODUCT NOMENCLATURE
L A 120 C 0 0 A 2 A A A 1 A
Model # Model Number Description Options
L Product Category L = Air Handling Unit-Cooling F = Air Handlng Unit-Heat Pump
A Product Identifier A = R-22 Standard Efficiency 2-Pipe
B = R-22 Standard Efficiency 4-Pipe
120
Nominal Cooling
Capacity
MBH
090 = 7-1/2 Ton
120 =10 Ton
150 = 12-1/2 Ton
180 = 15 Ton
240 = 20 Ton
C Heat Type C = Cooling Only
00 Nominal Heating
Capacity 00 = No Heat Installed
A Airflow Options A = None
2Voltage 6 = 208/230-460-3-60
A Factory Options A = None
B = Disconnect
AA Special Options AA = None
AC = Technicoat Coil
1 Generation 1 = 1st Generation 2 = 2ndGeneration
AStyle A = Style A B = Style B
*NOT AVAILABLE IN HEAT PUMP

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4Unitary Products Group
GENERAL
This completely assembled unit includes a well-insu-
lated cabinet, a DX cooling coil with copper tubes and
aluminum fins, 1 expansion valve, 1 distributor, throw-
away filters, a centrifugal blower, a blower motor con-
tactor and a small holding charge of Refrigerant-22. A
blower motor with adjustable drive is factory mounted
on every unit.
Supplemental resistance heaters, a supply air plenum,
a return air grille and a base are available as accesso-
ries for field installation.
The unit is shipped in the vertical position with a verti-
cal air discharge. The blower section can be reposi-
tioned as shown in Figure 2 for horizontal applications.
SAFETY CONSIDERATIONS
Installer should pay particular attention to the words:
NOTE, CAUTION, and WARNING. Notes are intended
to clarify or make the installation easier. Cautions are
given to prevent equipment damage. Warnings are
given to alert installer that personal injury and/or equip-
ment damage may result if installation procedure is not
handled properly.
RENEWAL PARTS
Refer to parts Manual for complete listing of replace-
ment parts on this equipment. The forms referenced in
this instruction may be ordered from:
Standard Register
2101 West Tecumseh Road
Norman, Oklahoma 73069
Toll Free TEL: [phone]
Toll Free FAX: [phone]
This instruction covers the installation and operation of
evaporator blower units. For information on the opera-
tion of the matching condensing unit, refer to Form
035-18506-001.
AGENCY APPROVALS
Design certified by UL as follows:
1. For use as a cooling coil/air handler only.
2. For indoor installation only.
INSPECTION
As soon as a unit is received, it should be inspected for
possible damage during transit. If damage is evident,
the extent of damage should be noted on the carrier's
freight bill. A separate request for inspection by the
carrier's agent should be made in writing.
Improper installation may create a condition
where the operation of the product could cause
personal injury or property damage.
Improper installation, adjustment, alteration,
service or maintenance can cause injury or
property damage. refer to this manual for
assistance or additional information, consult a
qualified installer, service agency.
This product must be installed in strict compli-
ance with the enclosed installation instructions
and any applicable local, state, and national
codes including but not limited to, building,
electrical and mechanical codes.

035-18525-001-B-0203
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TABLE 1: PHYSICAL DATA
DESCRIPTION UNIT MODEL
LA120
Evaporator
Coil
Rows Deep 3
Rows High 32
Finned Length (in.) 54.5
Fins / Inch 13
Tube O. D. (in.) 3/8
Face Area (Sq. Ft.) 12.1
Centrifugal1
Blower
1. Refer to data in Table 8 for complete motor specifications.
Wheel Dia. X Width (in.) 18 X 18
Filters2
2. Filters are throwaway type 2” filters may be used, if required by removing the 1” filter retaining angles provided in the filter rack.
Qty. & Size (in.) (6) 20 X 20 X 1
Face Area (Sq. Ft.) 16.7
Operating Charge (Refrigerant-22) Lbs. - Oz. 5-8
Weight (Lbs.) Shipping 439
Operating 399
Accessory
Weights (Lbs.)
Electric
Heaters
10 KW 66
16 KW 70
26 KW 74
36 KW 77
Supply Air Plenum 144
Base 65
Return Air Grille 19
Horizontal Suspension 68
Steam Coil 149
Hot Water Coil 135
TABLE 2: APPLICATION LIMITATIONS
Power
Supply
Voltage
Variation1
1. Utilization Range”A” in accordance with ARI Standard 110.
Supply Air Range
CFM
Entering Air Temperatures, ºF
Cooling-db/wb Heating-db
Min. Max. Min. Max. Min. Max. Min. Max.
208/230-3-60 187 252 2800 6800 65/67 96/72 - 77
460-3-60 432 504

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INSTALLATION
LIMITATIONS
This unit must be installed in accordance with all
national and local safety codes. If no local codes
apply, installation must conform to the appropriate
national code. The unit is designed to meet National
Safety code Standards. If components are to be added
to a unit to meet local codes, they are to be installed at
the dealer's and/or the customer's expense. See
Table 2 for application limitations.
LOCATION
The LA 120 is not designed for outdoor installation. It
must be located within the building structure, either
inside or outside the conditioned space.
The unit should be located as close to the condensing
unit as practical and positioned to minimize bends in
the refrigerant piping.
Units being installed vertically or horizontally can be set
directly on a floor or platform, or metal or wooden
beams can support them.
Units being installed horizontally can be suspended
from above as shown in Figure 1. Refer to Form 035-
16622-001 for more information on the installation of
the suspension accessory and for the individual load
on each hanger rod.
A field added secondary drain pan may be required in
locations where possible condensate overflow could
cause damage.
RIGGING AND HANDLING
Be careful when moving the unit. Do not remove any
packaging until the unit is near its final location.
The packaging consists of a bottom wooden skid that
can be lifted with a fork truck from any direction, a card-
board container that covers the entire unit, and strap-
ping that secures the cardboard container to the
bottom skid.
These units can be rigged with slings under the bottom
skid.
Before rigging any unit, determine its weight from
Table 1 . Before rigging a unit for horizontal installa-
tion, make sure that its weight will be distributed
equally.
Be careful when attaching the hanger rods.
Use a washer with a back-up nut on each rod
and tighten down against the cabinet so they
will not be allowed to turn or slip.
Spreader bars should be used to prevent
slings from crushing the unit panels and frame.

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CLEARANCES
The clearances listed on the unit dimension drawing
(Figure 10) are required for the proper service and
operation of the unit.
VERTICAL / HORIZONTAL INSTALLATION
The LA120 unit is shipped for vertical installation with a
vertical air discharge as shown in Figure 2, but may be
converted to other arrangements per the following
instructions:
1. Remove the panels from the blower section.
2. Remove the four Phillips machine bolts that hold
the coil and blower sections together. A bolt is
located near each corner.
3. Move the blower section to the proper location.
4. Attach the blower section to the coil section with
the machine bolts removed in Step 2.
5. Before replacing the panel, see Duct Connection
and Drain Connection.
Replace the panels.
FIGURE 1: UNIT SUSPENSION MOUNTING LA120 (HORIZONTAL APPLICATIONS)
TABLE 3: LA120 UNIT SUSPENSION WEIGHTS (LBS)
SUSP'N. POINT W/ 2 HP MOTOR W/ HEATER ACCESS W/ PLENUM ACCESS W/ HEATER & PLENUM
ACCESS
A95 95 85 85
B120 120 100 100
C95 115 165 185
D115 140 185 205
TOTAL WT.425 470 535 575
FIGURE 2: VERTICAL AND HORIZONTAL APPLICATION

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DUCT CONNECTIONS
All ducts should be designed and installed in accor-
dance with all national and/or local codes.
NOTE: Certain blower positions are not recommended
because the blower motor should not be mounted
upside down.
Ducts should be sized no smaller than the duct flanges
on the unit or the electric heater (if used). Refer to the
unit dimensions (Figure 10) and the heater detail (Fig-
ure 3) for these sizes. Refer to Form 035-16602-001
for installation instructions on the electric heater.
A supply air plenum (Figure 3), a base (Figure 4) and
a return air grille (Figure 5) are available as field-
installed accessories and one of the following respec-
tive instructions will be packed with each.
Form 035-16650-001 Supply Air Plenum
Form 035-16621-001 Return Air Grille
Form 035-16632-001 Base
The supply air plenum and the return air grille should
be used in lieu of ductwork only when a free blow/free
return application is practical.
FIGURE 1 : ELECTRIC HEAT ACCESSORY
HEATER
ELEMENT
CHAMBER
3/4
A
C
1DLE
F
M
G
H
K
B
ACCESS OPENING FOR POWER SUPPLY WIRING
1/2
W
IRING HARNESS LOCATION
T
his opening in the bottom of the heater
control box is used for the wiring harness
t
hat connects the heater accessory to the
basic unit. It is provided with a squeeze
connector for securing the wiring harness,
and its location corresponds to the loca-
t
ion of the 1-23/32 inch knockout in the top
panel of the basic unit.
CONTROL BOX
ACCESS PANEL
10KW THRU 30KW - Add a 1-1/4 inch conduit fitting
to the 1-23/32 inch hole for wire sizes up through
#1 AWG. Remove the knockout ring and add a
1-1/2 inch conduit fitting to the 1-31/32 inch hole
for wire sizes up through #0 AWG.
TABLE 4: ELECTRIC HEATER DIMENSIONS FA120
HEATER
MODEL
NOM.
kW
Heater Dimensions (inches)
ABCDEFGHKLM
2HS04501025, 46 10
28-1/2 25-1/4 14-1/4 1 4 1/2 5-1/2 1-1/2 1-1/2 22-1/4 19-1/4
2HS04501625, 46 16
2HS04502625, 46 26
2HS04503625, 48 36
FIGURE 3: SUPPLY AIR PLENUM ACCESSORY
A L T E R N A T E
A I R D I S C H A R G E
T O P P A N E L S
B L O W E R
U N I T
S U P P L Y
A I R
G R I L L E
FIGURE 4: BASE ACCESSORY (VERTICAL ONLY)
B L O W E R
U N I T
B L O W E R U N I T
B A S E P A N E L W h e n o u t d o o r a i r i s r e q u i r e d a h o l e c a n b e
c u t i n b a c k p a n e l f o r c o n n e c t i n g d u c t w o r k .

035-18525-001-B-0203
Unitary Products Group 9
DRAIN CONNECTION
The drain line MUST be trapped because the coil is
located on the negative side of the supply air blower. It
must also be protected from freezing temperatures.
A 7/8" OD stub connection is provided within the cabi-
net on both ends of the condensate drain pan for either
left hand or right hand piping connections. Refer to
Figure 6 for recommended drain piping.
The drain line is usually located on the same end of the
coil section as the refrigerant connections. The line
should be insulated where moisture drippage will be
objectionable or cause damage to the area. Seal the
unused drain connection with suitable mastic.
The 5" dimension must equal or exceed the negative
static pressure developed by the supply air blower. If it
does not, the condensate will not drain properly and
may overflow the drain pan. The trap must be at least
2" deep to maintain a water seal under all operating
conditions, especially during blower start up.
REFRIGERANT MAINS
Many service problems can be avoided by taking ade-
quate precautions to provide an internally clean and
dry system and by using procedures and materials that
conform with established standards.
Hard drawn copper tubing should be used where no
appreciable amount to bending around pipes or other
obstructions is necessary. Use long radius ells wher-
ever possible. If soft copper is used, care should be
taken to avoid sharp bends, which may cause a restric-
tion.
Fiber glass insulation and a sealing material such as
permagum should be packed around refrigerant lines
where they penetrate a wall to reduce vibration and to
retain some flexibility.
Support all refrigerant lines at minimum intervals with
suitable hangers, brackets or clamps.
Braze all copper to copper joints with Sil-Fos 5 or
equivalent brazing material. DO NOT use soft solder.
Never braze or solder the liquid and suction lines
together.
The complete suction line should be insulated with no
less than 1/2" ARMAFLEX or equivalent.
If it is desirable to tape or wire the liquid and suction
lines together for support purposes, they must be com-
pletely insulated from each other.
INSTALLING REFRIGERANT MAINS
The units are evacuated and dehydrated at the factory
and shipped with a holding charge of Refrigerant-22.
The suction and liquid connections are sealed with
copper discs.
Before starting installation of the mains, be sure the
unit has not developed a leak in transit by drilling a
small hole in the sealing discs. If pressure still exists,
the circuit may be considered leak free. If pressure
does not exist, the coil should be leak tested and the
necessary repairs should be made.
NOTE: To minimize the possibility of system failure due
to dirt and moisture, a filter-drier must be
installed in each liquid line as close to the
evaporator as possible. Filter-dryers are not
supplied with the evaporator blowers. They
are supplied with the matching YORK con-
densing sections.
FIGURE 5: RETURN AIR GRILLE ACCESSORY
(VERTICAL)
FIGURE 6: RECOMMENDED DRAIN PIPING
5 "
2 "
P L A S T I C
E L L *
STEEL
S T U B
C O N N E C T I O N
H O S E C L A M P S
E V A P O R A T O R
C O I L
D R A I N P A N
* F A C T O R Y S U P P L I E D

035-18525-001-B-0203
10 Unitary Products Group
The temperature required to make or break a brazed
joint is sufficiently high to cause oxidation of the copper
unless an inert atmosphere is provided.
The liquid, suction and drain connections inside the
unit must be piped to the outside. Refer to Unit Dimen-
sions for locations of the access openings in the unit
panel.
The factories for field placement into these access
openings supplies protective grommets.
The blower units are shipped with the coil section side
panels suitable for right hand piping connections when
viewed from the return air side of the unit.
In left hand piping is required, the two panels on the
right side of the coil section can be interchanged with
the single panel on the left side of the coil section.
When left-hand piping connections are installed, the
suction line must be insulated to prevent moisture from
condensing and being carried into the blower section.
EXPANSION VALVE BULB
The expansion valve bulb must be fastened in the 10 or
2 o’clock position to the suction line outside the cabinet
after the piping connections have been made. Use the
clamps supplied with the valve. Bulb must be
insulated with Armaflex or Mystic to assure proper
operation.
POWER AND CONTROL WIRING
Install electrical wiring in accordance with the latest
National Electrical Code (NFPA standard No. 70) and/
or local regulations. The unit should be grounded in
accordance with these codes.
Route the power wires into the unit through one of the
7/8" knockouts in the panel with the supply air opening,
and connect them to the terminals on blower motor
contactor 10M. Route the control wires into the unit
through the other 7/8" knockout, and connect them to
terminals on block TB1.CONTROL WIRE SIZING.
To determine the total circuit length, add the follow-
ing distances:
1 - Outdoor Unit to Indoor Unit _____________
2 - Indoor Unit to Thermostat _____________
3 - Thermostat to Indoor Unit _____________
4 - Indoor Unit to Outdoor Unit _____________
5 - Outdoor Unit to Elec. Heater _____________
Total Circuit Length _____________
If the unit includes an electric heat accessory, route the
power wires into heater control box in lieu of the unit.
Refer to the unit drawing in Figure 13 for locations of
these knockouts.
If the unit includes an electric heat accessory, route the
power wires into heater control box in lieu of the unit.
Refer to electric heat instruction Form 035-16602-001
for additional installation information.
NOTE: Three-phase motor rotation may be incorrect
when unit is first started up. Reverse phase
(leads L1 and L2) at contactor to obtain the
correct rotation.
Dry nitrogen should flow through the system at
all times when heat is being applied and until
the joint has cooled.
Wire Size
Maximum Total
Circuit Length
(Feet)
#19 Solid
#18 Solid
#18 Stranded
#16 Stranded
#14 Stranded
#12 Stranded
130
170
180
270
455
730
TABLE 5: ELECTRICAL DATA
Blower Motor HP Power Supply FLA LRA Maximum Fuse Size Amps Maximum Wire Length Ft.
2
208-3-60 7.5 49.0 15 103
230-3-60 6.8 55.0 15 126
460-3060 3.4 27.0 15 505

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SUPPLY AIR BLOWER ADJUSTMENT
The RPM of the supply air blower will depend on the
required CFM, the unit accessories and the static resis-
tances of both the supply and the return air duct sys-
tems. With this information, the RPM for the supply air
blower can be determined from the blower perfor-
mance in Table 8 .
Knowing the required blower RPM and the blower
motor HP, the setting (turns open) for the supply air
motor pulley can be determined form Table 5 .
Each motor pulley has:
1. A threaded barrel with two (2) flats (or notched
recesses) 180 degrees apart.
2. A movable flange with one setscrew.
After the movable flange has been rotated to the
proper number of “turns open”, the set screw
should be tightened against the flat on the barrel to
lock the movable flange in against the flat on the
barrel to lock the movable flange in place. If the
pulley includes a locking collar, the locking collar
must be loosed to adjust the setting of the movable
flange.
3. The tension on the belt should be adjusted for a
deflection of 3/16 of an inch per foot of belt span
with an applied force of 2 to 3 pounds. This adjust-
ment is made by moving the blower motor mount-
ing plate. Refer to Figure 7. Turning the
adjustment bolt (B) moves the motor mounting
plate up or down. Note - Never loosen the tow nuts
(C). Two hex nuts (A) have to be loosened to
move the mounting plate and retighten after the
mounting plate has been moved to the proper posi-
tion.
FIGURE 7: FIELD WIRING DIAGRAMS FOR POWER SUPPLY
COOLING ONLY UNITS AND UNITS WITH
STEAM OR HOT WATER COIL ACCESSORY
T
ERMINALS ON
SUPPLY AIR
BLOWER MOTOR
CONTACTOR 10M
GROUND
SCREW
POWER WIRING,
DESCONNECT SWITCH
AND FUSING TO BE
SUPPLIED BY FIELD
LINE VOLTAGE
POWER SUPPLY
*Not require on 060 (1-Phase
only) All other units are 3-Phase.
TERMINALS
ON FUSE HOLDER
IN ELECTRIC HEAR
CONTROL BOX
GROUND LUG
IN ELECTRIC HEAT
CONTROL BOX
POWER WIRING,
DESCONNECT
SWITCH
AND FUSING
(OR CIRCUIT
BREAKER)
TO BE SUPPLIED
BY FIELD
3-PHASE
LINE VOLTAGE
POWER SUPPLY
NOTE: USE COPPER
CONDUCTORS ONLY
WIRE IN ACCORDANCE WITH LOCAL
AND NATIONAL ELECTRICAL CODES
UNITS WITH ELECTRIC HEAT ACCESSORY
FIGURE 8: FIELD WIRING DIAGRAM COOLING
(COOLING ONLY)
YY
G
TERMINAL
BLOCK TB1
ON BLOWER
UNIT
*
RR
G
B
COOLING
TO
COND.
UNIT
24-VOLT
CONTROL
WIRING
TYPICAL TERMINALS
ON THERMOSTAT
Y
NOTE: See PN 036-13335-002
for applicable thermostats.
TABLE 6: SUPPLY AIR BLOWER MOTOR PULLY
ADJUSTMENT
TURNS
OPEN
BLOWER DRIVE RANGE (RPM)
549-716
5549
4582
3625
2655
1685
0716

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12 Unitary Products Group
4. All pulleys are factory aligned.
5. All supply air motor pulleys are factory set at 2
“turns open”.
After the supply air blower motor is operating,
adjust the resistances in both the supply and the
return duct system to balance the air distribution
throughout the conditioned space. The job specifi-
cations may require that this balancing be done by
someone other than the equipment installer.
To check the supply air CFM after the initial balancing
has been completed:
1. Drill two (2) 5/16-inch holes in the side panel as
shown in Figure 8.
2. Insert at least 8" of 1/4 inch tubing into each of
these holes for sufficient penetration into the air-
flow on both sides of the evaporator coil.
3. Using an inclined manometer, determine the pres-
sure drop across a dry evaporator coil. Since the
moisture on an evaporator coil may vary greatly,
measuring the pressure drop across a wet coil
under field conditions would be inaccurate. To
assure a dry coil, the refrigerant system should be
de-activated while the test is being run.
4. Knowing the pressure drop across a dry coil, the
actual CFM through the unit can be determined
from the curve in Figure 9.
If the CFM is above or below the specified valve, the
supply air motor pulley may have to be readjusted.
After on hour of operation, check the belt and pulleys
for tightness and alignment.
After readings have been obtained, remove the tubes
and seal up the drilled holes in the side panel. 5/16"
dot plugs (P/N 029-12880) are available through nor-
mal York parts ordering procedures.
FIGURE 9: TYPICAL MOTOR MOUNTING
ASSEMBLY
B
A
(DO NOT LOOSEN)
MOTOR
MOTOR MOUNT
C
FIGURE 10: HOLE LOCATIONS FOR PRESSURE
DROP READINGS
Failure to properly adjust the total system air
quantity can result in extensive blower dam-
age.
5 / 1 6 "
H O L E
5 / 1 6 "
H O L E
18"
7 "
22"
10"
E V A P O R A T O R
C O I L
F I L T E R S
C O I L S E C T I O N

035-18525-001-B-0203
Unitary Products Group 13
NOTE: Shut down the refrigerant system before taking
any test measurements to assure a dry evapo-
rator coil.
.
TABLE 7: BLOWER MOTOR AND DRIVE DATA
Unit
Model
Motor
Blower HP*
Blower
RPM
Adjustable Motor Pulley Fixed Blower Pulley Belt
Pitch Dia.
(Inches)
Bore
(Inches)
Pitch Dia.
(Inches)
Bore
(Inches) Designation Pitch Lg. (Inches)
LA120 2 549-716 3.1-4.1 7/8 9.5 1 A55 56.3
Motor Specifications
• 1750 RPM
• 208/230/460-3-60
•SolidBase
• 56 Frame
• Inherently Protected
• Permanently lubricated ball
bearings
FIGURE 11: PRESSURE DROP ACROSS A DRY EVAPORATOR COIL VS. SUPPLY AIR CFM

035-18525-001-B-0203
14 Unitary Products Group
FIGURE 12: BLOWER PERFORMANCE CURVE
TABLE 8: SUPPLY AIR BLOWER PERFORMANCE 1, 2
NOTE: Refer to Form 550.13-AD1 for blower performance curves.
RPM range for the standard, factory-mounted drive components.
1Available static pressure in IWG to overcome the resistance of the duct system and any accessories added to the unit. Refer to the respective tables for the
resistance of these accessories and for additional motor and drive data.
2 Motors can be selected to operate into their service factor because they are located in the moving air stream, upstream of any heating device. Units with steam or
hot water coils are the only exception.
LA120
3000
3500
4000
4500
5000
5500
6000
6500
7000
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 1.1
External Static
CFM
0 Turns
1 Tu r n
2 Turns
3 Turns
4 Turns
5 Turns
10 TON BLOWER PERFORMANCE
ESP CFM RPM Watts CFM RPM Watts CFM RPM Watts CFM RPM Watts CFM RPM Watts CFM RPM Watts
0.2 - - - 5775 680 2168 5402 650 1851 4990 616 1516 4571 582 1281 4250 548 1097
0.4 5521 713 2283 5409 684 1954 4810 653 1633 4326 618 1307 3785 582 1069 3484 550 903
0.6 4864 718 2006 4736 688 1695 4098 657 1353 3411 622 1052 2635 586 826 - - -
0.8 4221 722 1695 3780 693 1393 2860 661 1019 - - - - - - - - -
1 3223 728 1376 2625 697 1097 - - - - - - - - - - - -
0turns 1turn 2turns 3turns 4turns 5turns
Exceeds Amperage rating of motor.

035-18525-001-B-0203
Unitary Products Group 15
ACCESSORIES
• ELECTRIC HEATER
Add 15” to unit height when using 10, 16, 26, or 36
KW heater
• SUPPLY AIR PLENUM
Add 27” to unit height when used.
• BASE
TABLE 9: ACCESSORY STATIC RESISTANCE (IWG)(TO BE INCLUDED WITH DUCT SYSTEM STATIC
RESISTANCE)
120
3200 3600 4000 4400 4800
Electric Heaters
10 KW 0.02 0.02 0.03 0.03 0.04
16 KW 0.03 0.04 0.05 0.06 0.07
26 KW 0.06 0.07 0.09 0.11 0.13
36 KW 0.09 0.11 0.14 0.17 0.20
Supply Air Plenum 0.05 0.06 0.07 0.08 0.10
Return Air Grille 0.05 0.06 0.07 0.08 0.10
Hot Water Coil 0.19 0.24 0.30 0.35 0.40
FIGURE 13: UNIT DIMENSIONS AND CLEARANCES
2 7 - 5 / 8
2 - 3 / 8
2 - 3 / 1 6
5 6 - 3 / 8
1
2 - 3 / 1 6
3 1 - 5 / 8
3 - 1 / 8
6 2 - 5 / 8
1 - 1 / 4 " K N O C K O U T
F O R 7 / 8 " O D D R A I N
C O N N E C T I O N *
M u s t b e t r a p p e d )
F I L T E R A C C E S S P A N E L
F i l t e r s c a n b e r e m o v e d
t h r o u g h e i t h e r s i d e o f
t h e u n i t .
1 - 1 / 4 " K N O C K O U T F O R
5 / 8 " O D L I Q U I D C O N N E C T I O N *
C O I L
S E C T .
6 - 1 / 4 3 - 1 / 8
3 - 1 / 8 1 9
1 0
2 - 1 / 8
2 - 5 / 8 "
K N O C K -
O U T F O R
1 - 5 / 8 " O D
S U C T I O N
C O N N . *
3 2 - 3 / 8
1 8 - 7 / 8
6
5 - 1 / 2
5 - 7 / 8
B L O W E R
S E C T I O N
7 - 1 / 4 1 6 - 1 / 2
7 / 8
1 9 - 3 / 8 2 1 - 7 / 8
6 0 - 3 / 4
B L O W E R M O T O R A N D D R I V E A C C E S S P A N E L
A l w a y s o n t h e w i r i n g c o n n e c t i o n s i d e o f u n i t )
L o c a t e d o n o p p o s i t e s i d e O N L Y w h e n t h e b l o w e r
s e c t i o n h a s b e e n r o t a t e d 1 8 0 f r o m p o s i t i o n s h o w n .
1 - 2 3 / 3 2 " K N O C K O U T
R e m o v e o n l y w h e n E l e c t r i c
H e a t A c c e s s o r y i s u s e d .
7 / 8 " K N O C K O U T F O R P O W E R W I R I N G
D o n o t r e m o v e t h i s k n o c k o u t w h e n t h e u n i t i s e q u i p p e d w i t h a n E l e c t r i
c
H e a t A c c e s s o r y . R e f e r t o d e t a i l o f t h e H e a t e r A c c e s s o r y f o r p o w e r
w i r i n g a c c e s s o p e n i n g
7 / 8 " K N O C K O U T F O R
C O N T R O L W I R I N G
A L T E R N A T E
2 - 5 / 8 " K N O C K O U T *
* R e f e r t o I N S T A L L I N G R E F R I G E R A N T M A I N S i n i n s t a l l a t i o n i n s t r u c t i o n
w h e n p i p i n g t h r o u g h t h e o p p o s i t e s i d e o f t h e u n i t .
A I R
O U T
A I R
I N

Subject to change without notice. Printed in U.S.A. 035-18525-001-B-0203
Copyright © by Unitary Products Group2003. All rights reserved. Supersedes: 035-18525-001-A-0602
Unitary 5005 Norman
Products York OK
Group Drive 73069
MAINTENANCE
EVAPORATOR COIL
Do not allow dirt to accumulate on the evaporator coil
or other parts of the evaporator air circuit. Clean as
often as necessary to assure good system perfor-
mance. Use a brush, vacuum cleaner attachment or
other suitable means.
FILTERS
The filters must be replaced as often as necessary to
assure good air flow and filtering action.
Refer to Figure 10 for filter access panel location.
DRAIN PAN
The drain pan should be inspected regularly to assure
proper drainage.
LUBRICATION
The bearings for the blower shaft and the blower
motors are permanently lubricated and should not
require additional lubricant.
BELTS
Maintain belt tension to extend belt life. Replace when
signs of failure begin to appear.
MINIMUM CLEARANCES
Side Air with RETURN AIR opening 24”
Side with SUPPLY AIR opening1
1. Overall dimension of the unit will vary if an electric heater, a
supply air plenum or a base is used.
24”
Side with PIPING CONNECTIONS2
2. This dimension is required for removal of the DX coil. Only 26”
is required for normal servicing.
61”
Side opposite PIPING CONNECTIONS3
3. If the DX coil has to be removed, this dimension is required to
loosen screws that secure the coil to the unit frame. This dimen-
sion will also be required for blower motor access if the piping
connections are made on the opposite side of the unit.
26”
Bottom4
4. Allow enough clearance to trap the condensate drain lines.
-