INSTALLATION
2006 Lennox Industries Inc.
Dallas, Texas, USA
RETAIN THESE INSTRUCTIONS
FOR FUTURE REFERENCE
INSTRUCTIONS
15CHAX SERIES UNITS
PACKAGED ELECTRIC UNIT (2−5 TONS)
505,201M (38152A082)
01/08
Supersedes 05/06
Shipping & Packing List
1 − Assembled packaged electric unit
As soon as the unit is received, it should be inspected for
possible damage during transit. If you find any damage, immediately contact the last carrier.
WARNING
Improper installation, adjustment, alteration, service
or maintenance can cause property damage, personal injury or loss of life. Installation and service must
be performed by a licensed professional installer (or
equivalent) or service agency.
Litho U.S.A.
Table of Contents
Shipping & Packing List 1. . . . . . . . . . . . . . . . . . . . . . . . .
Unit Dimensions 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Parts Arrangement 3. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
General 3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Requirements 3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Location Selection 4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Rigging & Setting Unit 4. . . . . . . . . . . . . . . . . . . . . . . . . .
Clearances 4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Existing Common Vent Systems 5. . . . . . . . . . . . . . . . .
Condensate Drain 5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Filters 6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Supply & Return Connections 6. . . . . . . . . . . . . . . . . . . .
Compressors 6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Electrical 6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Blower Control Board 9. . . . . . . . . . . . . . . . . . . . . . . . . . .
System Operation Monitor 11. . . . . . . . . . . . . . . . . . . . . .
Unit Start−Up and Operation 13. . . . . . . . . . . . . . . . . . . .
Condenser Fan Clearances 14. . . . . . . . . . . . . . . . . . . . .
Maintenance 14. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
WARNING
If this unit is to be installed in a mobile or manufactured home application, the duct system must be
sized to achieve static pressures within the
manufacturer’s guidelines. All other installation
guidelines must also be followed. Failure to do so
may result in equipment damage, personal injury
and improper unit performance.
CAUTION
Danger of sharp metallic edges. Can cause injury.
Take care when servicing unit to avoid accidental
contact with sharp edges.
WARNING
Electric shock hazard. Can cause injury
or death. Before attempting to perform
any service or maintenance, turn the
electrical power to unit OFF at
disconnect switch(es). Unit may have
multiple power supplies.
01/08
*2P0108*
Page 1
505,201M
*P505201M*
15CHAX Unit Dimensions − inches (mm)
Model
Number
FG
B
E
D
2−1/2 (64)
DOWN−FLOW
SUPPLY AIR
OPENING
FF
AA
2−3/4
(70)
2−1/2 (64)
D
E
DOWNFLOW
RETURN AIR
OPENING
EE
TOP VIEW
BB
CCDD
Corner Weights
AA
Number
lbs. lbs. lbs. lbs. in. in.
15CHAX−24 75 94 117 94 16 29
C
15CHAX−30 75 94 117 94 16 29
15CHAX−36 83 97 121 104 16 30
15XHAX−42 110 138 163 129 21 33
15CHAX−48 114 139 164 134 21 33.5
15CHAX−60 119 145 171 140 21 33.5
BB CC DD EE FF
Center Of
Gravity
Model No.
15CHAX−24
15CHAX−30
15CHAX−36
15CHAX−42
15CHAX−48
15CHAX−60
2−1/2 (64)
END VIEW
D
2 (51)
D
2−3/4
JK
E
E
(70)
HORIZONTAL
RETURN
OPENINGS
H
AIR
(2)
FRONT VIEW
HORIZONTAL
SUPPLY AIR
A
OPENING
E
D
2−3/4
(70)
BACK VIEW
ELECTRICAL INLET
L
CONDENSATE DRAIN
END VIEW
A B C D E F
in.
34−1/4 870 65−3/8 1661 36−1/2 927 11−1/4 286 17−1/4 438 20 508
38−1/4 972 75 1905 46 1168 11−1/4 286 19−1/4 489 22 559
mm in. mm in. mm in. mm in. mm in. mm
15CHAX−24
15CHAX−30
15CHAX−36
15CHAX−42
15CHAX−48
15CHAX−60
Model No.
F G H J K L
in.
mm in. mm in. mm in. mm in. mm in. mm
20 508 8−1/2 216 3 76 20−1/4 514 4−1/2 114 19 483
22 559 9−1/4 241 3−1/4 83 22−1/4 572 4 102 16−1/4 413
Page 2
Parts Arrangement
General
These installation instructions are intended as a general
guide only, for use by an experienced, licensed contractor
(or equivalent).
The 15CHAX units are single−package electric units
designed for outdoor installation on a rooftop or a slab. The
units are equipped with a transformer and blower control
for applications which do not include electric heat. Electric
heat sections are available for separate order.
The unit must be sized based on heat loss and heat gain
calculations made according to the methods of the Air
Conditioning Contractors of America (ACCA).
The units are shipped assembled. All piping, refrigerant
charge, and electrical wiring are factory−installed and
tested. The units require electric power, condensate drain
and duct connections at the point of installation.
Use of this unit as a construction heater or air conditioner is
not recommended during any phase of construction. Very
low return air temperatures, harmful vapors and operation
of the unit with clogged or misplaced filters will damage the
unit.
If this unit has been used for heating or cooling of buildings
or structures under construction, the following conditions
must be met or the warranty will be void:
A room thermostat must control the unit. The use of
fixed jumpers that will provide continuous heating or
cooling is not allowed.
A pre−filter must be installed at the entry to the return air
duct.
The return air duct must be provided and sealed to the
unit.
Return air temperature range between 55°F (13°C)
and 80°F (27°C) must be maintained.
Air filters must be replaced and pre−filter must be re-
moved upon construction completion.
The unit components, duct system, air filters and evap-
orator coil must be thoroughly cleaned following final
construction clean−up.
The unit operating conditions (including airflow, cool-
ing operation, and heating operation) must be verified
according to these installation instructions.
Requirements
These units must be installed in accordance with all
applicable national and local safety codes.
These instructions are intended as a general guide and do
not supersede local codes in any way. Consult authorities
having jurisdiction before installation.
If components are to be added to a unit to meet local codes,
they are to be installed at the dealer’s and/or customer’s
expense.
These units are design listed by UL in both the United
States and Canada as follows:
For use as a cooling unit.
For outdoor installation only.
Page 3
For installation on combustible material.
WARNING
Product contains fiberglass wool.
Disturbing the insulation in this product during
installation, maintenance, or repair will expose you
to fiberglass wool dust. Breathing this may cause
lung cancer. (Fiberglass wool is known to the State
of California to cause cancer.)
Fiberglass wool may also cause respiratory, skin,
and eye irritation.
To reduce exposure to this substance or for further
information, consult material safety data sheets
available from address shown below, or contact your
supervisor.
Lennox Industries Inc.
P.O. Box 799900
Dallas, TX 75379−9900
Location Selection
Use the following guidelines to select a suitable location for
these units.
1 − Unit is designed for outdoor installation only. Unit must
be installed so all electrical components are protected
from water.
2 − Condenser coils must have an unlimited supply of air.
3 − For ground level installation, use a level pre−fabricated
pad or use a level concrete slab with a minimum thick-
ness of 4 inches. The length and width should be at
least 6 inches greater than the unit base. Do not tie the
slab to the building foundation.
4 − Maintain level within a tolerance of 1/4 inch maximum
across the entire length or width of the unit.
Rigging & Setting Unit
Exercise care when moving the unit. Do not remove any
packaging until the unit is near the place of installation. An
optional lifting lug kit (92M51) may be purchased
separately for use in rigging the unit for lifting. Spreaders
MUST be used across the top of the unit. Recommended
spreader length: 2, 2−1/2, 3−ton units −− 44"; 3−1/2, 4, 5−ton
units −− 54".
CAUTION
Before lifting a unit, make sure that the weight is distributed equally on the cables so that it will lift evenly.
Units may also be moved or lifted with a forklift while still in
the factory supplied packaging.
NOTE − Length of forks must be a minimum of 42 inches.
Accessory Lift Kit
Lifting Bracket
Accessory
Sheet Metal
Screw
Figure 1
Clearances
All units require certain clearances for proper operation
and service. Refer to figure 2 for the clearances required
for combustible construction, servicing, and proper unit
operation.
Service Clearances
REAR
30
(762)
FRONT
*Rear clearance is 18" (457) when required for
accessory maintenance.
NOTE − Top Clearance − 36 in. (914 mm)
NOTE − Entire perimeter of unit base requires
support when elevated above mounting surface.
Figure 2
NOTE − Do not permit overhanging structures or shrubs to
obstruct condenser air discharge outlet.
In the U.S. units may be installed on combustible floors
made from wood or class A, B, or C roof covering material.
In Canada, units may be installed on combustible floors.
3 (156)*
48 (1219)
24
(610)
Page 4
Existing Common Vent Systems
The 15CHAX packaged cooling units with auxiliary electric
heat may replace an existing furnace which is being removed from a venting system commonly run with separate
gas appliances. In this case, the existing vent system is
likely to be too large to properly vent the remaining attached appliances.
Conduct the following test while each appliance is operating and the other appliances (which are not operating) remain connected to the common venting system. If the venting system has been installed improperly, you must
correct the system as indicated in the general venting requirements section.
1 − Seal any unused openings in the common venting sys-
tem.
2 − Inspect the venting system for proper size and horizon-
tal pitch. Determine that there is no blockage, restriction, leakage, corrosion, or other deficiencies which
could cause an unsafe condition.
3 − Close all building doors and windows and all doors be-
tween the space in which the appliances remaining
connected to the common venting system are located
and other spaces of the building. Turn on clothes dryers and any appliances not connected to the common
venting system. Turn on any exhaust fans, such as
range hoods and bathroom exhausts, so they will operate at maximum speed. Do not operate a summer exhaust fan. Close fireplace dampers.
4 − Follow the lighting instructions. Turn on the appliance
that is being inspected. Adjust the thermostat so that
the appliance operates continuously.
5 − After the main burner has operated for 5 minutes, test
for leaks of flue gases at the draft hood relief opening.
Use the flame of a match or candle, or smoke from a
cigarette, cigar, or pipe.
6 − After determining that each appliance connected to the
common venting system is venting properly, (step 3)
return all doors, windows, exhaust fans, fireplace
dampers, and any other gas−burning appliances to
their previous mode of operation.
7 − If a venting problem is found during any of the preced-
ing tests, the common venting system must be modified to correct the problem.
Resize the common venting system to the minimum
vent pipe size determined by using the appropriate
tables in Appendix G. (These are in the current standards of the National Fuel Gas Code
ANSI-Z223.1/NFPA 54 in the USA, and the appropri-
ate Category 1 Natural Gas and Propane appliances
venting sizing tables in the current standards of the
CSA B149 Natural Gas and Propane Installation
Codes in Canada.)
Condensate Drain
The 15CHAX unit is equipped with a 3/4 inch FPT coupling
for condensate line connection. Plumbing must conform to
local codes. Use a sealing compound on male pipe
threads.
The drain line must be properly trapped and routed to a
suitable drain. See figure 3 for proper drain arrangement.
The drain line must pitch to an open drain or pump a
minimum of 1 inch per 10 feet to prevent clogging of the
line. Seal around drain connection with suitable material to
prevent air leakage into return air system.
NOTE − Drain line connection may not carry the weight of
the unsupported drain line. Support the drain line, if
necessary.
Drain piping should not be smaller than drain connection at
coil. An open vent in drain line will some times be required
due to line length, friction and static pressure. Drains
should be constructed in a manner to facilitate future cleaning.
NOTE − The condensate drain line MUST be trapped to
provide proper drainage.
CAUTION
Condensate line connection must be hand−tightened. Do not use tools.
Typical Condensate Drain
Unit
Positive Liquid Seal Required
Drain Connection
12.00”
Max.
Figure 3
1.00” Min.
3.00” Min.
Page 5
Filters
Filters are not factory−supplied with the unit; however,
optional internally installed filter kits are available. Filter kit
92M54 is used with 2, 2−1/2 and 3−ton units. Filter kit 92M55
is used with 3−1/2, 4 and 5−ton units. The filter kits
accommodate the use of 1", 2" or 4" filters. If the optional
filter kit is not used, a filter must be field−installed.
Filters must always be installed ahead of evaporator coil
and must be kept clean or replaced. Dirty filters will reduce
the airflow of the unit. Filter sizes are shown in table 1.
Removing Supply and Return
Air Opening Covers
2
1.Remove screw and lift.
2.Slide cover to free back pin.
1
Base
Table 1
Unit Filter Size
Unit Model Filter Size Filter Quantity
−24, −30, −36 20 in. X 25 in. 1
−42, −48, −60 16 in. X 25 in. 2
The Healthy Climate® PureAir® air purification system
(PCO20−28) may be used with 15CHAX units installed in
horizontal air discharge applications only. Installation
hardware kit (Y0629) is required to install the PCO20−28
(X8787) in the packaged unit. The PCO20−28 is designed
for universal voltage, and is ready to operate at 208/230V.
When used, the PCO should be installed before the unit is
set in place and before the duct connections are made.
Supply & Return Duct Connections
The duct system should be designed and sized according
to the methods in Manual Q of the Air Conditioning
Contractors of America (ACCA).
A closed return duct system shall be used. This shall not
preclude use of economizers or outdoor fresh air intake. It
is recommended that supply and return duct connections
at the unit be made with flexible joints.
The supply and return air duct systems should be designed
for the CFM and static requirements of the job. They
should NOT be sized by simply matching the
dimensions of the duct connections on the unit.
Ducting installed outdoors MUST be insulated and
waterproofed.
Figure 4
The upper return air opening cover must be removed when
the PureAir
used. In PCO applications, both upper and lower return air
openings must be covered by the return air plenum to
ensure proper PCO operation. The upper return air
opening is not required in horizontal applications when the
PCO is not used.
®
air purification system (PCO20−28) is being
Compressors
Units are shipped with the compressor mountings
factory−adjusted and ready for operation.
CAUTION
Do not loosen compressor mounting bolts.
Electrical
All wiring should be done in accordance with the
current National Electric Code ANSI/NFPA No. 70 in
the United States. In Canada, wiring must be done in
accordance with the current CSA C22.2 Part 1. Local
codes may take precedence.
Use wiring with a temperature limitation of 75C min.; run
the 208 or 230 volt, 60 hertz electric power supply through a
fused disconnect switch to control box of unit and connect
as shown in the wiring diagram located on the inside of the
control access panel. Refer to figure 5 for electrical access.
CAUTION
When fastening duct system to side duct flanges on
unit, insert screws through duct flanges only. Do not
insert screws through casing. Outdoor duct must be
insulated and waterproofed.
The 15CHAX unit is shipped ready for horizontal air
discharge (side duct connections). If bottom air discharge
is desired, the covers must be removed from the supply
and return air openings on the bottom of the unit and
re−installed to cover the side openings.
Figure 5
Page 6
Unit must be electrically grounded in accordance with local
codes or in the absence of local codes with the National
Electric Code, ANSI/NFPA No. 70 (latest edition) or CSA
C22.2 Part 1 (latest edition).
Power supply to the unit must comply with all applicable
codes and NEC or CEC. A fused disconnect switch should
be field provided for the unit. The switch must be separate
from all other circuits. If any of the wire supplied with the
unit must be replaced, replacement wire must be of the
type shown on the wiring diagram.
Electrical wiring must be sized to carry minimum circuit
ampacity marked on the unit. USE COPPER
CONDUCTORS ONLY. Each unit must be wired with a
separate branch circuit and be properly fused.
WARNING
Unit is equipped with a single−pole contactor. Line
voltage is present at all components when unit is not
in operation. Disconnect all remote electric power
supplies before opening access panel. Unit may
have multiple power supplies. Failure to disconnect
all power supplies could result in personal injury or
death.
the installation instructions packaged with the electric heat
section.
Thermostat
The room thermostat should be located on an inside wall
where it will not be subject to drafts, sun exposure or heat
from electrical fixtures or appliances. Follow
manufacturer’s instructions enclosed with thermostat for
general installation procedure. Color coded insulated wires
(# 18 AWG) should be used to connect thermostat to unit.
Typical Single−Phase Unit Wiring Connections
CAUTION
When connecting electrical power and control wiring to the unit, waterproof type connectors MUST be
used so that water or moisture cannot be drawn into
the unit during normal operation.
WARNING
Unit must be grounded in accordance with national
and local codes. Failure to ground unit properly can
result in personal injury or death.
See figure 6 for typical field wiring connections and figure 7
for typical unit wiring diagram.
Optional Electric Heat
Optional electric heat is available and must be purchased
separately. Install the electric heat section as outlined in
Figure 6
Page 7
Typical Wiring Diagram
15CHAX Series Packaged Electric Units
Figure 7
Page 8
Blower Control Board (A54)
!
WARNING
Electric shock hazard. Can cause injury or
death. Before attempting to perform any
service or maintenance, turn the electrical
power to unit OFF at disconnect
switch(es). Unit may have multiple power
supplies.
15CHAX units are equipped with a variable speed motor
that is capable of maintaining a specified CFM throughout
the external static range. A particular CFM can be obtained
by positioning jumpers (COOL, HEAT, and ADJUST) on
the blower control board. The HEAT and COOL jumpers
are labeled A, B, C and D. Each of the numbers corresponds with an air volume (CFM) setting. The ADJUST
jumper is labeled Test, −, +, and Norm. The + and − pin settings are used to add or subtract a percentage of the CFM
selected. The Test jumper is used to operate the motor in
the test mode. See figure 8.
Factory settings for the blower speed jumpers are given in
the wiring diagram in figure 7. Figure 8 shows the blower
control board. Use tables 2, 3 and 4 to determine the correct air volume for operation in heat and cool mode.
The CFM LED located on the blower control board flashes
one time per 100 cfm to indicate selected blower speed.
For example, if the unit is operating at 1000 CFM, CFM
LED will flash 10 times. If the CFM is 1150, CFM LED will
flash 11 full times plus one fast or half flash.
At times the light may appear to flicker or glow. This takes
place when the control is communicating with the motor between cycles. This is normal operation.
Read through the jumper settings section before adjusting
the jumper to obtain the appropriate blower speed.
To change jumper positions, gently pull the jumper off the
pins and place it on the desired set of pins. The following
section outlines the different jumper selections available
and conditions associated with each one. Refer to figure 8.
After the CFM for each application has been determined,
the jumper settings must be adjusted to reflect those given
in tables 2, 3 and 4. From the tables, determine which row
most closely matches the desired CFM. Once a specific
row has been chosen (+, NORMAL, or −), CFM volumes
from other rows cannot be used. Below are descriptions of
the jumper selections.
The variable speed motor slowly ramps up to and down
from the selected air flow during both cooling and heating
demand. This minimizes noise and eliminates the initial
blast of air when the blower is initially energized.
ADJUST
The ADJUST pins allow the motor to run at normal speed,
approximately 15 percent higher, or approximately 15 percent lower than normal speed. Tables 2, 3 and 4 give three
rows (+, NORMAL, and −) with their respective CFM volumes. Notice that the normal adjustment setting for cool
speed position D in table 2 is 900 CFM. The + adjustment
setting for that position is 1035 CFM and for the − adjustment setting is 765 CFM. After the adjustment setting has
been determined, choose the remaining speed settings
from those offered in the table in that row.
The TEST pin is available to bypass the blower control and
run the motor at approximately 70 percent to make sure
that the motor is operational. This is used mainly in troubleshooting. The G terminal must be energized for the motor
to run.
DIAGNOSTIC
LED
BLOWER CONTROL BOARD (A54)
16−PIN PLUG
(BOARD TO MOTOR)
Figure 8
Page 9
ADJUST
SELECTOR PINS
(Setting affects both
heating and cooling
modes)
HEATING SPEED
SELECTOR PINS
COOLING SPEED
SELECTOR PINS
COOL
JUST"
Jumper
JUST"
Jumper
JUST"
Jumper
The COOL jumper is used to determine the CFM during
cooling operation. This jumper selection is activated for
cooling when Y1 is energized.
The blower motor runs at 80 percent of the selected air flow
for the first 7−1/2 minutes of each cooling demand. This feature allows for greater humidity removal and saves energy.
In the cooling mode, the blower control board delays
blower operation for 5 seconds after the compressor starts.
The blower continues to operate for 90 seconds after the
compressor is de−energized.
HEAT
The HEAT jumper is used to determine CFM during backup electric heat operation only. These jumper selections
are activated only when W is energized.
In the backup heat mode, the blower continues to operate
for 2 minutes after the heating demand is satisfied.
NOTE − Due to the nature of electric heat, CFM settings are
limited.
CONTINUOUS FAN
When the thermostat is set for Continuous Fan" operation
and there is no demand for heating or cooling, the blower
control will provide 50 percent of the COOL CFM selected.
NOTE − With the proper thermostat and subbase, continuous blower operation is possible by closing the R to G circuit. Cooling blower delay is also functional in this mode.
DEHUMIDIFICATION
The blower control board includes an HUM terminal which
provides for connection of a humidistat. The JV1 resistor
on the blower control board must be cut to activate the
HUM terminal. The humidistat must be wired to open on
humidity rise. When the dehumidification circuit is used,
the variable speed motor will reduce the selected air flow
rate by 25 percent when humidity levels are high. An LED
(D1) lights when the blower is operating in the dehumidification mode.
Table 2
15CHAX−24, 15CHAX−30 Blower Performance
0 through 0.80 in. w.g. (0 through 200 Pa) External Static Pressure Range
AD-
"
Jumper
Setting
NORM 1000 470 800 380 600 285 900 425 1000 470 1000 470 1000 470 1000 470 500 235 400 190 300 140 450 210
A
cfm
+ 1150 545 920 435 690 325 1035 490 1150 545 1150 545 1150 545 1150 545 575 270 460 215 345 165 520 245
850 400 680 320 510 240 765 360 1000 470 1000 470 1000 470 1000 470 425 200 340 160 300 140 385 180
−
COOL" Speed
B C D A B C D A B C D
L/s cfm L/s cfm L/s cfm L/s cfm L/s cfm L/s cfm L/s cfm L/s cfm L/s cfm L/s cfm L/s cfm L/s
Jumper Speed Positions
HEAT" Speed CONTINOUS FAN" Speed
Table 3
15CHAX−36 Blower Performance
0 through 0.80 in. w.g. (0 through 200 Pa) External Static Pressure Range
AD-
"
Jumper
Setting
NORM 1200 565 1000 470 800 380 1100 520 1200 565 1200 565 1000 470 1000 470 600 285 500 235 400 190 550 260
A
cfm
+ 1380 650 1150 545 920 435 1265 575 1380 650 1380 650 1150 545 1150 545 690 325 575 270 460 215 635 300
1020 480 850 400 680 320 935 440 1200 565 1200 565 1000 470 1000 470 510 240 425 200 350 165 470 220
−
COOL" Speed
B C D A B C D A B C D
L/s cfm L/s cfm L/s cfm L/s cfm L/s cfm L/s cfm L/s cfm L/s cfm L/s cfm L/s cfm L/s cfm L/s
Jumper Speed Positions
HEAT" Speed CONTINOUS FAN" Speed
Table 4
15CHAX−42, 15CHAX−48, 15CHAX−60, Blower Performance
0 through 0.80 in. w.g. (0 through 200 Pa) External Static Pressure Range
AD-
"
Jumper
Setting
NORM 1800 850 1600 755 1400 660 1200 565 1400 660 1400 660 1400 660 1400 660 900 425 800 380 700 330 600 285
A
cfm L/s cfm L/s cfm L/s cfm L/s cfm L/s cfm L/s cfm L/s cfm L/s cfm L/s cfm L/s cfm L/s cfm L/s
+ 2070 975 1840 870 1610 760 1380 650 1610 760 1610 760 1610 760 1610 760 1035 490 920 435 805 380 690 325
− 1530 720 1360 640 1190 560 1020 480 1400 660 1400 660 1400 660 1400 660 765 360 680 320 595 280 510 240
COOL" Speed
B C D A B C D A B C D
Jumper Speed Positions
HEAT" Speed CONTINOUS FAN" Speed
Page 10
System Operation Monitor (LSOM)
The system operation monitor (A132) detects the most
common fault conditions in the air conditioning system.
When an abnormal condition is detected, the module communicates the specific condition through its ALERT and
TRIP lights. The module is capable of detecting both mechanical and electrical system problems. See figure 9 for
the system operation monitor.
System Operation Monitor (A132)
POWER LED
DATA OUTPUT
Y
C
R
ALERT LED
TRIP LED
DATA OUTPUT
CONNECTOR
.25" SPADE
CONNECTOR (5)
Figure 9
IMPORTANT
This monitor does not provide safety protection. The
monitor is a monitoring device only and cannot control or shut down other devices.
LSOM LED Functions
Power LED (green) −− Voltage within the range of
19−28VAC is present at the system monitor power connection.
Alert LED (yellow) −− Communicates an abnormal system
condition through a unique flash code. The alert LED
flashes a number of times consecutively; then pauses;
then repeats the process. This consecutive flashing corresponds with a particular abnormal condition.
Trip LED (red) −− Indicates a demand signal from the thermostat; but detects no current to the compressor.
Flash code number −− Corresponds to a number of LED
flashes, followed by a pause, and then repeated.
Trip & Alert LEDs flashing simultaneously −− Indicates that
the control circuit voltage is too low for operation.
Reset ALERT flash code by removing 24VAC power from
monitor. Last ALERT flash code will display for 1 minute after monitor is powered on.
LSOM codes are given in table 5.
Page 11
Table 5
System Operation Monitor LED Troubleshooting Codes
Status LED Condition Status LED Description Status LED Troubleshooting Information
Green Power" LED ON Module has power 24VAC control power is present at the module terminal.
Green Power" LED
Module not powering up
OFF
Red Trip" LED ON System and compressor
check out OK
Thermostat demand signal
Y1 is present, but compressor not running
Red Trip" & Yellow
Alert" LEDs Flashing
Yellow Alert" Flash
Code 1*
Simultaneous flashing. Indicates that the control circuit voltage is too low for operation.
Long Run Time −
Compressor is running
extremely long run cycles
Yellow Alert" Flash
Code 2*
System Pressure Trip −
Discharge or suction pressure out of limits or
compressor overloaded
Yellow Alert" Flash
Code 3*
Yellow Alert" Flash
Short Cycling − Compres-
sor is running only briefly
Locked Rotor
Code 4*
Yellow Alert" Flash
Open Circuit
Code 5*
Yellow Alert" Flash
Code 6*
Yellow Alert" Flash
Code 7*
Yellow Alert" Flash
Code 8*
Yellow Alert" Flash
Code 9*
Open Start Circuit −
Current only in run circuit
Open Run Circuit − Current
only in start circuit
Welded Contactor −
Compressor always runs
Low Voltage − Control
circuit <17VAC
*Flash code number corresponds to a number of LED flashes, followed by a pause, and then repeated. Reset ALERT flash code
by removing 24VAC power from monitor; last code will display for 1 minute after monitor is powered on.
Determine/verify that both R and C module terminals are connected
and voltage is present at both terminals.
1.
2.
3.
Verify Y terminal is connected to 24VAC at contactor coil.
Verify voltage at contactor coil falls below 0.5VAC when off.
Verify 24VAC is present across Y and C when thermostat
demand signal is present; if not present, R and C wires are reversed.
1.
2.
3.
4.
5.
6.
1.
2.
3.
4.
5.
6.
7.
1.
2.
aged).
3.
4.
5.
1.
2.
3.
4.
1.
2.
3.
4.
1.
2.
3.
4.
5.
6.
7.
1.
2.
3.
1.
2.
1.
2.
1.
2.
Compressor protector is open.
Outdoor unit power disconnect is open.
Compressor circuit breaker or fuse(s) is open.
Broken wire or connector is not making contact.
Low pressure switch open if present in the system.
Compressor contactor has failed to close.
Low refrigerant charge.
Evaporator blower is not running.
Evaporator coil is frozen.
Faulty metering device.
Condenser coil is dirty
Liquid line restriction (filter drier blocked if present)
Thermostat is malfunctioning
.
.
.
High head pressure.
Condenser coil poor air circulation (dirty, blocked, dam-
Condenser fan is not running.
Return air duct has substantial leakage.
If low pressure switch is present, see Flash Code 1 info.
Thermostat demand signal is intermittent.
Time delay relay or control board is defective.
If high pressure switch is present, see Flash Code 2 info.
If low pressure switch is present, see Flash Code 1 info.
Run capacitor has failed.
Low line voltage (contact utility).
Excessive liquid refrigerant in the compressor.
Compressor bearings are seized.
Outdoor unit power disconnect is open.
Unit circuit breaker or fuse(s) is open.
Unit contactor has failed to close.
High pressure switch is open and requires manual reset.
Open circuit in compressor supply wiring or connections.
Unusually long compressor protector reset time due to
extreme ambient temperature.
Compressor windings are damaged.
Run capacitor has failed.
Open circuit in compressor start wiring or connections.
Compressor start winding is damaged.
Open circuit in compressor start wiring or connections.
Compressor start winding is damaged.
Compressor contactor failed to open.
Thermostat demand signal not connected to module.
Control circuit transformer is overloaded.
Low line voltage (contact utility).
Page 12
Unit Start−Up and Operation
Each 15CHAX packaged cooling unit is factory−charged
with R−410A refrigerant. The compressor is hermetically
sealed, internally sprung and base−mounted with
immediately stop. The circulating air blower continues
operating through a 90−second delay.
Unit compressors have internal protection. If there is an
abnormal rise in the compressor temperature, the
protector will open and the compressor will stop.
rubber−insulated hold−down bolts.
System Performance
Pre−Start Check List:
1 − Make sure refrigerant lines do not rub against the cabi-
net or each other.
2 − Inspect all electrical wiring, both factory− and field−
installed, for loose connections.
3 − Check voltage at the disconnect switch. Voltage must
be within the range listed on the unit nameplate. If not,
consult power company and have voltage condition
corrected before starting unit.
4 − Recheck voltage with unit running. If power is not with-
in the range listed on the unit nameplate, stop the unit
and consult the power company. Check unit amperage. Refer to unit nameplate for correct running amps.
5 − Make sure filter is in place before unit start−up.
6 − Before placing the unit into full operation, energize the
unit for three false starts. Energize the compressor
just long enough for it to make a few revolutions, wait
five to seven minutes before repeating a second and
third time.
Cooling Sequence of Operation
When the thermostat calls for cooling, the R" to Y" circuit
is closed to energize the compressor contactor. The
contactor brings on both the compressor and outdoor fan.
The thermostat also closes the R" to G" circuit to energize
the circulating air blower. When the cooling demand is
satisfied, the thermostat opens the circuits, as well as the
compressor contactor. The compressor and outdoor fan
For maximum performance of this cooling system, the
operating temperatures and pressure should be checked
and subcooling determined at Standard ARI test conditions
of 82 F outdoor temperature / 80 F indoor dry bulb / 67 F
indoor wet bulb. If subcooling measured deviates from
values in table 6, refrigerant charge should be adjusted
accordingly for maximum performance.
Table 6
Suction Superheat Values
Unit Model No.
15CHAX−24
15CHAX−30
15CHAX−36 15
15CHAX−42
15CHAX−48
15CHAX−60
Verify system performance using table 7 as a general
guide. Table 7 should not be used for charging unit. Minor
variations in these pressures may be expected due to differences in installations. Significant differences could
mean that the system is not properly charged or that a problem exists with some component in the system.
Used carefully, this table could serve as a useful service
guide. Data is based on 80°F dry bulb / 67°F wet bulb return
air. Allow unit operation to stabilize before taking pressure
readings.
Suction Superheat
82F OD / 80F IDDB
/ 67F IDWB
12
10
Table 7
Normal Operating Pressures
80°F db / 67°F wb RETURN AIR Air Temperature Entering Outdoor Coil (°F)
UNIT PRESSURE 65 70 75 80 82 85 90 95 100 105 110 115
15CHAX−24 142 143 144 146 146 147 148 149 150 151 152 153
15CHAX−30 134 136 138 140 141 142 144 146 148 149 151 152
15CHAX−36
15CHAX−42
15CHAX−48 140 141 142 144 144 145 146 147 148 149 150 151
15CHAX−60 143 144 145 146 146 147 147 148 149 150 151 152
15CHAX−24 219 242 264 287 296 310 333 355 379 398 430 457
15CHAX−30 232 255 277 300 309 323 345 368 390 408 440 470
15CHAX−36
15CHAX−42
15CHAX−48 243 264 285 307 315 328 349 370 391 408 440 470
15CHAX−60 257 280 303 326 335 349 372 395 418 436 468 497
Suction
Liquid
143 144 146 147 148 149 151 152 155 155 157 157
140 140 140 141 141 141 142 142 143 144 145 147
244 268 292 316 326 340 363 369 410 429 461 493
225 247 269 291 300 314 337 357 383 402 434 457
Page 13
Condenser Fan Clearances
The top of the condenser fan should be 1−1/2 inches from
the bottom of the top grille. This dimension should be
checked and the fan should be adjusted accordingly any
time servicing of the outdoor fan system is required.
Maintenance
At the start of each cooling season, this equipment should
be serviced by a licensed professional technician (or
equivalent). Periodic inspection and maintenance normally
consists of changing or cleaning filters.
Filters
Not supplied. Inspect once a month. Replace disposable or
clean permanent type as necessary. DO NOT replace permanent type with disposable.
Accessories
Description
Filter Kit (2−ton to 3−ton capacity units) 92M54
Filter Kit (3−1/2−ton to 5−ton capacity units) 92M55
PCO20−28 X8787
Installation Hardware Kit for PCO20−28 Y0629
Motors
Indoor, outdoor fan and vent motors are permanently
lubricated and require no further lubrication. Motors should
be cleaned yearly to prevent the accumulation of dust and
dirt on the windings or motor exterior.
Coil
Dirt and debris should not be allowed to accumulate on the
coil surfaces or other parts in the air conditioning circuit.
Cleaning should be performed as often as necessary. Use
a brush, vacuum cleaner attachment, or other suitable
means. If water is used to clean the coil, be sure the power
to unit is shut off prior to cleaning.
NOTE − Care should be used when cleaning the coil so that
the coil fins are not damaged.
Do not permit the hot condenser air discharge to be obstructed by overhanging structures or shrubs.
LENNOX Cat.
Number
Page 14
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