Lennox 13ACD Series User manual

Page 1 ©2005 Lennox Industries Inc.
Corp. 0518−L8
13ACD
Service Literature Revised 03−2007
13ACD SERIES UNITS
The 13ACD is a residential split-system condensing unit
with SEER ratings up to 14.80. The series is designed for
use with expansion valves (TXV) or refrigerant flow control
(RFC). All 13ACD units utilize scroll compressors.
13ACD condensing units are available in 1−1/2, 2, 2 -1/2, 3, 3
-1/2, 4 and 5 ton capacities. All major components (indoor
blower and coil) must be matched according to Lennox rec-
ommendations for the compressor to be covered under war-
ranty. Refer to the Engineering Handbook for approved sys-
tem matchups.
Information contained in this manual is intended for use by
qualified service technicians only. All specifications are subject
to change.
This manual is divided into sections which discuss the
major components, refrigerant system, charging proce-
dure, maintenance and operation sequence.
WARNING
Improper installation, adjustment, alteration, service
or maintenance can cause property damage, person-
al injury or loss of life. Installation and service must
be performed by a qualified installer or service
agency.
WARNING
Refrigerant can be harmful if it is inhaled. Refrigerant
must be used and recovered responsibly.
Failure to follow this warning may result in personal
injury or death.
TABLE OF CONTENTS
Specifications / Electrical Data Page 2. . . . . . . . .
I Unit Components Page 3. . . . . . . . . . . . . . . . . . .
II Refrigerant System Page 5. . . . . . . . . . . . . . . . .
III Charging Page 6. . . . . . . . . . . . . . . . . . . . . . . . .
IV Maintenance Page 11. . . . . . . . . . . . . . . . . . . . . .
V Wiring and Operating Sequence Page 12. . . . .
ELECTROSTATIC DISCHARGE (ESD)
Precautions and Procedures
CAUTION
Electrostatic discharge can affect electronic
components. Take precautions during unit instal-
lation and service to protect the unit’s electronic
controls. Precautions will help to avoid control
exposure to electrostatic discharge by putting
the unit, the control and the technician at the
same electrostatic potential. Neutralize electro-
static charge by touching hand and all tools on an
unpainted unit surface before performing any
service procedure.
IMPORTANT
The Clean Air Act of 1990 bans the intentional venting
of (CFC’s and HFC’s) as of July 1, 1992. Approved
methods of recovery, recycling or reclaiming must be
followed. Fines and/or incarceration my be levied for
noncompliance.

Page 2
SPECIFICATIONS
General
Data
Model No. 13ACD−018 13ACD−024 13ACD−030 13ACD−036 13ACD−042 13ACD−048
(−1, −2 units)
13ACD−060
Nominal Tonnage 1.5 2 2.5 3 3.5 4 5
Connections
(t)
Liquid line o.d. − in. 3/8 3/8 3/8 3/8 3/8 3/8 3/8
(sweat) Suction line o.d. − in. 3/4 3/4 3/4 7/8 7/8 7/8 1-1/8
1Refrigerant (R-22) furnished 4 lbs. 0 oz. 4 lbs. 8 oz. 5 lbs. 5 oz. 6 lbs. 15 oz. 6 lbs. 15 oz. 9 lbs. 8 oz.
(12 lbs 12oz)
13 lbs. 6 oz.
Outdoor
Cil
Net face area
ft
Outer coil 13.22 15.11 13.22 13.22 15.11 18.67 (24.50) 24.50
Coil - sq. ft. Inner coil − − − − − − 12.60 12.60 14.40 17.96 (23.56) 23.56
Tube diameter − in. 5/16 5/16 5/16 5/16 5/16 5/16 5/16
Number of rows 1 1 2 2 2 2 2
Fins per inch 22 22 22 22 22 22 22
Outdoor
F
Diameter − in. 18 18 18 18 18 22 22
Fan Number of blades 3 3 4 4 4 4 4
Motor hp 1/5 1/5 1/5 1/5 1/3 1/4 1/4
Cfm 2500 2500 2450 2450 2930 3670 (3830) 3830
Rpm 1100 1100 1100 1100 1100 825 825
Watts 200 200 200 200 310 315 (330) 330
Shipping Data − lbs. 1 package 122 129 150 150 177 191 (233) 236
ELECTRICAL DATA
Line voltage data − 60 hz − 1ph 208/230V 208/230V 208/230V 208/230V 208/230V 208/230V 208/230V
2Maximum overcurrent protection (amps) 15 20 30 30 45 40 60
3Minimum circuit ampacity 10.7 14.1 18.7 19.1 25.9 25.7 33.3
Compressor Rated load amps 7.7 10.4 14.1 14.4 19.2 19.2 26.1
p
Power factor .98 .96 .96 .96 .98 .94 .96
Locked rotor amps 40.0 54.0 67.0 77.0 104.0 97.0 141.0
Condenser
FMt
Full load amps 1.0 1.0 1.0 1.0 1.9 1.7 1.7
Fan Motor Locked rotor amps 1.9 1.9 1.9 1.9 4.1 3.1 3.1
OPTIONAL ACCESSORIES − must be ordered extra
Compressor Crankcase
Ht
93M04    
p
Heater 93M05   
Compressor Hard Start Kit 10J42      
p
81J69 
Compressor Low Ambient Cut−Off 45F08       
Compressor Sound Cover 69J03       
Compressor Time−Off Control 47J27       
Freezestat 3/8 in. tubing 93G35       
5/8 in. tubing 50A93       
Hail Guards 92M88   
92M89  
12W21 
92M94 
High Pressure Switch Kit 94J46       
Indoor Blower Off Delay
Relay
58M81       
Loss of Charge Switch Kit 84M23       
Low Ambient Kit 24H77       
Mounting Base 69J06 
g
69J07  
Refrigerant
Line Sets
L15−41−20, L15−41−30,
L15−41−40, L15−41−50
  
L15−65−30, L15−65−40,
L15−65−50
  
Field Fabricate 
Unit Stand−Off Kit 94J45       
NOTE  Extremes of operating range are plus 10% and minus 5% of line voltage.
1Refrigerant charge sufficient for 15 ft. length of refrigerant lines.
2HACR type circuit breaker or fuse.
3Refer to National or Canadian Electrical Code manual to determine wire, fuse and disconnect size requirements.

Page 3
I − UNIT COMPONENTS
13ACD UNIT COMPONENTS
FIGURE 1
OUTDOOR FAN/MOTOR CONTROL BOX
SUCTION LINE
SUCTION LINE
VALVE
LIQUID LINE
VALVE
DISCHARGE
LINE
COMPRESSOR
A − Control Box (Figure 2)
13ACD units are not equipped with a 24V transformer. All
24 VAC controls are powered by the indoor unit. Refer to
wiring diagram.
Electrical openings are provided under the control box cov-
er. Field thermostat wiring is made to color-coded pigtail
connections.
1 − Compressor Contactor K1
The compressor is energized by a contactor located in the
control box. See figure 2. Single−pole contactors are used
in 13ACD series units. K1 is energized by the indoor ther-
mostat terminal Y1 (24V) when thermostat demand is
present.
DANGER
Electric Shock Hazard.
May cause injury or death.
Line voltage is present at all compo-
nents when unit is not in operation on
units with single pole contactors.
Disconnect all remote electrical power
supplies before opening unit panel.
Unit may have multiple power supplies.
FIGURE 2
DUAL CAPACITOR
(C12)
TIMED OFF
CONTROL
(OPTION)
COMPRESSOR
CONTACTOR
(K1)
13ACD UNIT CONTROL BOX
GROUNDING
LUG
2 − Dual Capacitor C12
The compressor and fan in 13ACD series units use per-
manent split capacitor motors. The capacitor is located
inside the unit control box (see figure 2). A single dual"
capacitor (C12) is used for both the fan motor and the
compressor (see unit wiring diagram). The fan side and
the compressor side of the capacitor have different MFD
ratings. Ratings will be on compressor nameplate and
condenser fan nameplate.
3 − Timed Off Control TOC (option)
The time delay is electrically connected between thermo-
stat terminal Y and the compressor contactor. Between
cycles, the compressor contactor is delayed for 5 minutes ±
2 minutes but may last as long as 8 minutes. At the end of
the delay, the compressor is allowed to energize. When
thermostat demand is satisfied, the time delay opens the
circuit to the compressor contactor coil and the compressor
is de−energized.
4 − High Pressure Switch (option)
The manual−reset high pressure switch is located in the liq-
uid line. When liquid line pressure exceeds the factory set-
ting of 410 + 10 psi, the switch opens and shuts off the com-
pressor.
5 − Pressure Switch (−1 units only)
The auto−reset pressure switch is located in the suction
line. When suction line pressure drops below the factory
setting of 25 + 5 psi, the switch opens and shuts off the
compressor.

Page 4
B − Compressor
FIGURE 3
SCROLL COMPRESSOR
DISCHARGE
SUCTION
All 13ACD units utilize a scroll compressor. The scroll com-
pressor design is simple, efficient and requires few moving
parts. A cutaway diagram of the scroll compressor is shown in
figure 3. The scrolls are located in the top of the compressor
can and the motor is located just below. The oil level is immedi-
ately below the motor.
The scroll is a simple compression concept centered around
the unique spiral shape of the scroll and its inherent properties.
Two identical scrolls are mated together forming concentric
spiral shapes (figure 4). One scroll remains stationary, while
the other is allowed to "orbit" (figure 5). Note that the orbiting
scroll does not rotate or turn but merely orbits the stationary
scroll.
NOTE − During operation, the head of a scroll compressor may
be hot since it is in constant contact with discharge gas.
FIGURE 4
STATIONARY SCROLL
ORBITING SCROLL
DISCHARGE
SUCTION
CROSS−SECTION OF SCROLLS
TIPS SEALED BY
DISCHARGE PRESSURE
DISCHARGE
PRESSURE
The counterclockwise orbiting scroll draws gas into the outer
crescent shaped gas pocket created by the two scrolls (figure 5
− 1). The centrifugal action of the orbiting scroll seals off the
flanks of the scrolls (figure 5 − 2). As the orbiting motion contin-
ues, the gas is forced toward the center of the scroll and the
gas pocket becomes compressed (figure 5 − 3). When the
compressed gas reaches the center, it is discharged vertically
into a chamber and discharge port in the top of the compressor
(figure 4). The discharge pressure forcing down on the top
scroll helps seal off the upper and lower edges (tips) of the
scrolls (figure 4). During a single orbit, several pockets of gas
are compressed simultaneously providing smooth continuous
compression.
The scroll compressor is tolerant to the effects of liquid return. If
liquid enters the scrolls, the orbiting scroll is allowed to separate
from the stationary scroll. The liquid is worked toward the cen-
ter of the scroll and is discharged. If the compressor is re-
placed, conventional Lennox cleanup practices must be used.
12
34
SUCTION
POCKET
SUCTION
ORBITING SCROLL
STATIONARY SCROLL
SUCTION SUCTION
DISCHARGE
POCKET
SUCTION INTERMEDIATE PRESSURE
GAS
CRESCENT
SHAPED
GAS POCKET
HIGH PRESSURE GAS
FLANKS SEALED
BY CENTRIFUGAL
FORCE
MOVEMENT OF ORBIT
FIGURE 5

Page 5
Due to its efficiency, the scroll compressor is capable of draw-
ing a much deeper vacuum than reciprocating compres-
sors. Deep vacuum operation can cause internal fusite
arcing resulting in damaged internal parts and will result
in compressor failure. Never use a scroll compressor for
evacuating or to pump system into a vacuum. This type
of damage can be detected and will result in denial of
warranty claims.
The scroll compressor is quieter than a reciprocating com-
pressor, however, the two compressors have much different
sound characteristics. The sounds made by a scroll compres-
sor do not affect system reliability, performance, or indicate
damage.
See compressor nameplate or ELECTRICAL DATA for
compressor specifications.
C − Condenser Fan Motor
All units use single−phase PSC fan motors which require a run
capacitor. In all units, the condenser fan is controlled by
the compressor contactor.
ELECTRICAL DATA tables in this manual show specifi-
cations for condenser fans used in 13ACDs.
Access to the condenser fan motor on all units is gained
by removing the seven screws securing the fan assem-
bly. See figure 6. The condenser fan motor is removed
from the fan guard by removing the four nuts found on the
top panel. Drip loops should be used in wiring when ser-
vicing motor. See figure 7 if condenser fan motor re-
placement is necessary.
Make sure all power is disconnected before
beginning electrical service procedures.
DANGER
FAN
CONDENSER FAN MOTOR
AND COMPRESSOR ACCESS
Remove (7) screws
REMOVE (7) SCREWS
SECURING FAN GUARD.
REMOVE FAN GUARD/FAN
ASSEMBLY.
MOTOR
FAN GUARD
WIRING
FIGURE 6
RACEWAY
Remove (4) nuts
ALIGN FAN HUB FLUSH WITH END OF SHAFT
FIGURE 7
II − REFRIGERANT SYSTEM
A − Plumbing
Field refrigerant piping consists of liquid and suction lines
from the condensing unit (sweat connections) to the indoor
evaporator coil (flare or sweat connections). Use Lennox
L15 (sweat) series line sets as shown in table 1.
TABLE 1
Refrigerant Line Sets
Model
Valve Field Size
Connections Recommended Line Set
M
o
d
e
l
Liquid
Line
Vapor
Line
Liquid
Line
Vapor
Line
L15
Line Sets
−018
−024
−030
3/8 in.
(10 mm)
3/4 in.
(19 mm)
3/8 in
(10 mm)
3/4 in.
(19 mm)
L15−41
15 ft. − 50 ft.
(4.6 m − 15 m)
−036
−042
−048
3/8 in.
(10 mm)
7/8 in
(22 mm)
3/8 in.
(10 mm)
7/8in
(22 mm)
L15−65
15 ft. − 50 ft.
(4.6 m − 15 m)
−060 3/8 in.
(10 mm)
1−1/8 in.
(29 mm)
3/8 in.
(10 mm)
1−1/8 in.
(29 mm)
Field
Fabricated
NOTE − Units are designed for line sets of up to fifty feet (15
m). For applications longer than fifty feet, consult the Len-
nox Refrigerant Piping Guide (Corp. 9351−L9).Select line
set diameters from table 1 to ensure that oil returns to the
compressor.
B − Service Valves
The liquid line and vapor line service valves (figures 9 and
8) and gauge ports are used for leak testing, evacuating,
charging and checking charge. See table 2 for torque re-
quirements.
Each valve is equipped with a service port which has a fac-
tory−installed Schrader valve. A service port cap protects
the Schrader valve from contamination and serves as the
primary leak seal.

Page 6
Table 2
Torque Requirements
Part Recommended Torque
Service valve cap 8 ft.− lb. 11 NM
Sheet metal screws 16 in.− lb. 2 NM
Machine screws #10 28 in.− lb. 3 NM
Compressor bolts 90 in.− lb. 10 NM
Gauge port seal cap 8 ft.− lb. 11 NM
To Access Schrader Port:
1 − Remove service port cap with an adjustable wrench.
2 − Connect gauge to the service port.
3 − When testing is complete, replace service port cap. Tight-
en finger tight, then an additional 1/6 turn.
To Open Service Valve:
1 − Remove the stem cap with an adjustable wrench.
2 − Use a service wrench with a hex−head extension to
back the stem out counterclockwise as far as it will go.
NOTE − Use a 3/16" hex head extension for liquid line
sizes or a 5/16" extension for vapor line sizes.
3 − Replace the stem cap. Tighten finger tight, then tighten
an additional 1/6 turn.
To Close Service Valve:
1 − Remove the stem cap with an adjustable wrench.
2 − Use a service wrench with a hex−head extension to turn
the stem clockwise to seat the valve. Tighten the stem
firmly.
NOTE − Use a 3/16" hex head extension for liquid line
sizes or a 5/16" extension for vapor line sizes.
3 − Replace the stem cap. Tighten finger tight, then tighten
an additional 1/6 turn.
Ball Valve (Valve Open)
FIGURE 8
Schrader valve
service port
service port
cap
stem cap
stem
Use Adjustable Wrench
To open: rotate Stem Clockwise 90°.
To close: rotate Stem Counter-clockwise 90°.
ball
(shown open)
to outdoor coil
to indoor coil
Service Valve
(Valve Closed)
Schrader valve open
to line set when valve is
closed (front seated)
service
port
service
port cap
stem cap
insert hex
wrench here
(valve front seated)
to outdoor coil
to indoor coil
Service Valve
(Valve Open)
Schrader
valve
service
port
service port
cap
insert hex
wrench here
to indoor coil
to outdoor coil
stem cap
FIGURE 9
Vapor Line Ball Valve
Vapor line service valves function the same way as the oth-
er valves, the difference is in the construction. These valves
cannot be repaired. If a valve has failed, you must replace it.
A ball valve is illustrated in figure 8.
The ball valve is equipped with a service port with a factory−
installed Schrader valve. A service port cap protects the
Schrader valve from contamination and assures a leak−free
seal.
III − CHARGING
The unit is factory−charged with the amount of HCFC−22 re-
frigerant indicated on the unit rating plate. This charge is
based on a matching indoor coil and outdoor coil with a 15
foot (4.5 m) line set. For varying lengths of line set, refer to
table 3 for refrigerant charge adjustment. A blank space is pro-
vided on the unit rating plate to list actual field charge.
IMPORTANT
If line length is greater than 15 feet (4.5 m) add this
amount. If line length is less than 15 feet (4.5 m),
subtract this amount.

Page 7
LIQUID LINE
3/8 in. (10 mm)
TABLE 3
Ounce per 5 foot (ml per mm) adjust
from 15 foot (4.5m) line set*
*If line set is greater than 15 ft. (4.5 m) add this amount. If line set
is less than 15 feet (4.5 m) subtract this amount
SET DIAMETER
3 ounce per 5 feet (90 ml per 1524 mm)
Units are designed for line sets up to 50 feet (15.2 m).
Consult Lennox Refrigerant Piping Manual
Corp.9351−L9 and available on the Lennox DaveNet
web site for line sets over 50 feet (15.2 m).
A − Pumping Down System
CAUTION
Deep vacuum operation (operating compressor
below 0 psig) can cause internal fusite arcing
resulting in a damaged or failed compressor. This
type of damage will result in denial of warranty claim.
The system may be pumped down when leak checking the
line set and indoor coil or making repairs to the line set or
indoor coil. Attach gauge manifold then follow below:
1− Close liquid line valve.
2− Start outdoor unit.
3− Monitor suction gauge. Stop unit when 0 psig is reached.
4− Close vapor line valve.
B − Leak Testing
After the line set has been connected to the indoor and out-
door units, check the line set connections and indoor unit
for leaks.
WARNING
Fire, Explosion and Personal Safety
Hazard.
Failure to follow this warning could
result in damage, personal injury or
death.
Never use oxygen to pressurize or
purge refrigeration lines. Oxygen,
when exposed to a spark or open
flame, can cause damage by fire and
/ or an explosion, that can result in
personal injury or death.
WARNING
Danger of explosion!
When using a high pressure gas such
as dry nitrogen to pressurize a refriger-
ant or air conditioning system, use a
regulator that can control the pressure
down to 1 or 2 psig (6.9 to 13.8 kPa).
Using an Electronic Leak Detector or Halide
1 − Connect a cylinder of HCFC-22 to the center port of the
manifold gauge set.
2 − With both manifold valves closed, open the valve on the
HCFC-22 cylinder (vapor only).
3 − Open the high pressure side of the manifold to allow the
HCFC-22 into the line set and indoor unit. Weigh in a
trace amount of HCFC-22. [A trace amount is a maxi-
mum of 2 ounces (57 g) or 3 pounds (31 kPa) pressure.]
Close the valve on the HCFC-22 cylinder and the valve
on the high pressure side of the manifold gauge set.
Disconnect the HCFC-22 cylinder.
4 − Connect a cylinder of nitrogen with a pressure regulat-
ing valve to the center port of the manifold gauge set.
5 − Connect the manifold gauge set high pressure hose to
the vapor valve service port. (Normally, the high pres-
sure hose is connected to the liquid line port; however,
connecting it to the vapor port better protects the man-
ifold gauge set from high pressure damage.)
6 − Adjust the nitrogen pressure to 150 psig (1034 kPa).
Open the valve on the high side of the manifold gauge
set which will pressurize line set and indoor unit.
7 − After a few minutes, open a refrigerant port to ensure
the refrigerant you added is adequate to be detected.
(Amounts of refrigerant will vary with line lengths.)
Check all joints for leaks. Purge nitrogen and HCFC-22
mixture. Correct any leaks and recheck.
C − Evacuating the System
Evacuating the system of noncondensables is critical for
proper operation of the unit. Noncondensables are defined
as any gas that will not condense under temperatures and
pressures present during operation of an air conditioning
system. Noncondensables and water vapor combine with
refrigerant to produce substances that corrode copper pip-
ing and compressor parts.
NOTE − This evacuation process is adequate for a new
installation with clean and dry lines. If excessive mois-
ture is present, the evacuation process may be re-
quired more than once.
IMPORTANT
Use a thermocouple or thermistor electronic vacuum
gauge that is calibrated in microns. Use an instrument
that reads from 50 microns to at least 10,000 microns.
1 − Connect manifold gauge set to the service valve ports :
 low pressure gauge to vapor line service valve
 high pressure gauge to liquid line service valve
2 − Connect micron gauge.
3 − Connect the vacuum pump (with vacuum gauge) to the
center port of the manifold gauge set.
4 − Open both manifold valves and start the vacuum
pump.

Page 8
5 − Evacuate the line set and indoor unit to an absolute
pressure of 23,000 microns (29.01 inches of mercury).
During the early stages of evacuation, it is desirable to
close the manifold gauge valve at least once to deter-
mine if there is a rapid rise in absolute pressure. A
rapid rise in pressure indicates a relatively large leak. If
this occurs, repeat the leak testing procedure.
NOTE − The term absolute pressure means the total
actual pressure within a given volume or system,
above the absolute zero of pressure. Absolute pres-
sure in a vacuum is equal to atmospheric pressure mi-
nus vacuum pressure.
6 − When the absolute pressure reaches 23,000 microns
(29.01 inches of mercury), close the manifold gauge
valves, turn off the vacuum pump and disconnect the
manifold gauge center port hose from vacuum pump.
Attach the manifold center port hose to a nitrogen cylin-
der with pressure regulator set to 150 psig (1034 kPa)
and purge the hose. Open the manifold gauge valves to
break the vacuum in the line set and indoor unit. Close
the manifold gauge valves.
CAUTION
Danger of Equipment Damage.
Avoid deep vacuum operation. Do not use compres-
sors to evacuate a system.
Extremely low vacuums can cause internal arcing
and compressor failure.
Damage caused by deep vacuum operation will void
warranty.
7 − Shut off the nitrogen cylinder and remove the manifold
gauge hose from the cylinder. Open the manifold
gauge valves to release the nitrogen from the line set
and indoor unit.
8 − Reconnect the manifold gauge to the vacuum pump,
turn the pump on, and continue to evacuate the line set
and indoor unit until the absolute pressure does not rise
above 500 microns (29.9 inches of mercury) within a
20−minute period after shutting off the vacuum pump
and closing the manifold gauge valves.
9 − When the absolute pressure requirement above has
been met, disconnect the manifold hose from the vacu-
um pump and connect it to an upright cylinder of
HCFC-22 refrigerant. Open the manifold gauge valves
to break the vacuum from 1 to 2 psig positive pressure in
the line set and indoor unit. Close manifold gauge valves
and shut off the HCFC-22 cylinder and remove the man-
ifold gauge set.
D − Charging
Units are factory-charged with the amount of HCFC−22 re-
frigerant indicated on the unit rating plate. This charge is
based on a matching indoor coil and outdoor coil with 15
feet (4.6 m) line set. For varying lengths of line set, refer to
table 4 for refrigerant charge adjustment.
TABLE 4
Refrigerant Charge per Line Set Lengths
Liquid Line
Set Diameter
Oz. per 5 ft. (g per 1.5 m) adjust
from 15 ft. (4.6 m) line set*
3/8 in. (9.5 mm) 3 ounce per 5 ft. (85 g per 1.5 m)
NOTE − *If line length is greater than 15 ft. (4.6 m), add this amount. If
line length is less than 15 ft. (4.6 m), subtract this amount.
The outdoor unit should be charged during warm weather.
However, applications arise in which charging must occur
in the colder months. The method of charging is determined
by the unit’s refrigerant metering device and the outdoor
ambient temperature.
Measure the liquid line temperature and the outdoor ambi-
ent temperature as outlined below:
1. Connect the manifold gauge set to the service valves:
low pressure gauge to vapor valve service port
high pressure gauge to liquid valve service port
2. Close manifold gauge set valves. Connect the center
manifold hose to an upright cylinder of HCFC−22.
3. Set the room thermostat to call for heat. This will create
the necessary load for properly charging the system in
the cooling cycle.
4. Use a digital thermometer to record the outdoor ambi-
ent temperature.
5. When the heating demand has been satisfied, switch
the thermostat to cooling mode with a set point of 68F
(20C). When pressures have stabilized, use a digital
thermometer to record the liquid line temperature.
6. The outdoor temperature will determine which charg-
ing method to use. Proceed with the appropriate charg-
ing procedure.
Charge Using Weigh−in Method (RFC/TXV Sys-
tems) − Outdoor Temp. <65°F (18°C)
If the system is void of refrigerant, or if the outdoor ambient
temperature is cool, use the weigh−in method to charge the
unit. Do this after any leaks have been repaired.
1. Recover the refrigerant from the unit.
2. Conduct a leak check, then evacuate as previously out-
lined.
3. Weigh in the charge according to the total amount
shown on the unit nameplate.
If weighing facilities are not available or if you are charging
the unit during warm weather, follow one of the other proce-
dures outlined below.

Page 9
Charge Using Subcooling Method
Outdoor Temp. >65°F (18°C)
If you charge a fixed orifice system when the outdoor ambi-
ent is 65F (18C) or above, use the subcooling method to
charge the unit.
1. With the manifold gauge hose still on the liquid service
port and the unit operating stably, use a digital
thermometer to record the liquid line temperature.
2. At the same time, record the liquid line pressure reading.
3. Use a temperature/pressure chart for HCFC−22 to
determine the saturation temperature for the liquid line
pressure reading.
4. Subtract the liquid line temperature from the saturation
temperature (according to the chart) to determine
subcooling.
Saturation Temperature F (C)
Liquid Line Temperature F (C)
=Subcooling Value F (C)
5. Compare the subcooling value with those in table 5 for
13ACD units with fixed orifices and table 6 for 13ACD
units with TXV. If subcooling is greater than shown,
recover some refrigerant. If subcooling is less than
shown, add some refrigerant.
TABLE 5
Subcooling Values For RFC Systems
Outdoor
Liquid Subcooling [+ 1F (.6C)]
O
ut
d
oor
Temp.
F(C) −018 −024 −030 −036 −042
−048
−1, −2
units
−048 −060
65 (18) 13
(7)
13
(7) 7 (4) 14 (8)
15
(8.3) 9 (5) 11 (6)
13
(7)
70 (21) 13
(7)
12
(6.7)
6
(3.3)
13
(7)
14
(8) 9 (5) 10 (5.6)
12
(6.7)
75 (24) 10
(5.6)
11
(6) 5 (3) 13 (7)
13
(7) 9 (5) 9 (5) 12 (6.7)
80 (27) 10
(5.6)
11
(6) 5 (3) 12 (6.7)
12
(6.7) 9 (5) 8 (4.5)
12
(6.7)
85 (29) 8
(4.5)
10
(5.6) 5 (3) 11 (6)
11
(6) 9 (5) 7 (4) 11 (6)
90 (32) 8
(4.5)
10
(5.6)
4
(2.2)
10
(5.6)
10
(5.6) 9 (5) 5 (2.8)
10
(5.6)
95 (35) 7 (4) 10
(5.6)
4
(2.2) 9 (5) 9 (5) 9 (5) 5 (2.8)
10
(5.6)
100 (38) 7 (4) 10
(5.6) 3 (2) 9 (5) 8 (4.5) 9 (5) 3 (1.7) 9 (5)
105 (41) 6
(3.3) 9 (5) 3 (2) 8 (4.5) 7 (4) 9 (5) 3 (1.7) 9 (5)
110 (43) 6
(3.3)
8
(4.5) 2 (1) 6 (3.3) 7 (4) 9 (5) 2 (1.1) 9 (5)
115 (45) 3 (2) 6
(3.3) 2 (1) 6 (3.3) 5 (3) 8 (4.5)
2
(1.1)
8
(4.5)
Charge using Subcooling Method
(TXV Systems)  Outdoor Temp. t65ºF (18ºC)
This charging procedure should not be used if ambient tem-
peratures are below 65ºF. For best results, indoor tempera-
ture should be 70ºF (21ºC) to 80ºF (26ºC).
1. Restrict the airflow (see figure 10) through the outdoor
coil to achieve pressures from 200−250 psig . These
higher pressures are necessary for checking the
charge. Block equal sections of air intake panels and
move coverings sideways until the liquid pressure is in
the above noted ranges.
Blocking Outdoor Coil
*Outdoor coil should be blocked one
side at a time with cardboard or plastic
sheet until proper testing pressures are
reached.
cardboard or plastic sheet
*Four−sided unit shown.
FIGURE 10
2. With the manifold gauge hose installed on the liquid
service port and the unit operating stably, use a digital
thermometer to record the liquid line temperature.
3. At the same time, record the liquid line pressure read-
ing.
4. Use a temperature/pressure chart for HCFC−22 refrig-
erant to determine the saturation temperature for the
liquid line pressure reading.
5. Subtract the refrigerant saturation temperature from
the liquid line temperature to determine subcooling.
Compare to table 6.
Saturation Temperature F (C)
Liquid Line Temperature F (C)
=Subcooling Value F (C)
TABLE 6
Subcooling Values For TXV Systems
13ACD −018 −024 −030 −036 −042 −048 −060
°F (C°) 8
(4.4)
8
(4.4)
4
(2.2)
7
(3.8)
10
(5.6) 9 (5) 14 (8)
Charge Using Approach Method (TXV Systems)
− Outdoor Temperature >65°F (18°C)
When charging an expansion valve system when the out-
door ambient temperature is 65F (18C) or above, it is
best to charge the unit using the approach method. Sub-
tract the outdoor ambient temperature from the liquid line
temperature to determine the approach temperature.
Liquid Line Temperature F (C)
Outdoor Ambient Temperature F (C)
=Approach Value F (C)
The resulting difference (approach temperature) should
agree with the values given in table 7. If not, add refrigerant
to lower the approach temperature or recover refrigerant
from the system to increase the approach temperature.

Page 10
Checking Charge Using Normal Operating Pressures
IMPORTANT
Use table 8 to help perform maintenance checks.
Table 8 is not a procedure for charging the system. Mi-
nor variations in these pressures may be due to differ-
ences in installations. Significant deviations could
mean that the system is not properly charged or that
a problem exists with some component in the system.
TABLE 7
Approach Values
13ACD Model −018 −024 −030 −036 −042 −048 −060
Temp. °F (°C) 6 (3.3) 10 (5.6) 11 (6) 9 (5) 6 (3.3) 6 (3.3) 8 (4.4)
Approach Value is the Liquid Line Temperature minus Outdoor Ambient Temperature [ºF (ºC) + 1ºF (0.5ºC)]
NOTE − For best results, use the same digital thermometer to check both outdoor ambient and liquid temperatures.
TABLE 8
Normal Operating Pressures In psig (liquid and suction +/− 2 psig)*
Normal Operating Pressures
13ACD
Model −018 −024 −030 −036 −042 −048−1, −2 units −048 −060
Values below are typical pressures; indoor unit match up, indoor air quality equipment, and indoor load will cause the
pressures to vary.
*Temp. 5F
(5C) Liquid Line Pressure/Vapor Line Pressure
Expansion Valve (TXV)
65 (18) 141 / 80 147 / 79 141 / 76 145 / 74 143 / 78 145 / 80 140 / 77 151 / 76
70 (21) 154 / 81 159 / 79 154 / 76 157 / 75 153 / 79 157 / 81 152 / 77 164 / 77
75 (24) 166 / 81 173 / 80 167 / 77 170 / 76 167 / 80 170 / 81 165 / 77 177 / 78
80 (27) 180 / 82 187 / 81 181 / 78 186 / 76 182 / 80 184 / 82 179 / 78 192 / 78
85 (29) 195 / 82 218 / 82 195 / 78 201 / 77 198 / 81 198 / 82 192 / 78 207 / 79
90 (32) 209 / 83 202 / 81 210 / 79 217 / 77 215 / 81 214 / 83 209 / 80 223 / 80
95 (35) 222 / 83 234 / 82 227 / 80 234 / 78 231 / 82 230 / 84 227 / 81 240 / 80
100 (38) 244 / 84 251 / 83 249 / 81 251 / 79 249 / 83 247 / 84 243 / 81 259 / 81
105 (41) 258 / 85 267 / 84 260 / 81 268 / 79 268 / 84 265 / 85 261 / 82 277 / 81
110 (43) 276 / 85 287 / 84 278 / 82 288 / 80 287 / 84 283 / 85 279 / 83 297 / 82
115 (45) 294 / 86 307 / 85 299 / 83 309 / 81 308 / 85 303 / 86 296 / 83 318 / 83
Fixed Orifice (RFC)
65 (18) 144 / 73 147 / 68 140 / 66 150 / 67 147 / 70 145 / 70 143 / 73 150 / 67
70 (21) 157 / 76 160 / 71 152 / 68 162 / 70 158 / 72 156 / 72 154 / 75 163 / 70
75 (24) 167 / 78 173 / 74 166 / 71 176 / 72 171 / 75 170 / 75 167 / 78 177 / 72
80 (27) 182 / 80 189 / 77 180 / 74 190 / 74 184 / 77 183 / 78 180 / 79 191 / 75
85 (29) 196 / 82 203 / 79 196 / 76 205 / 76 198 / 78 198 / 80 193 / 81 207 / 77
90 (32) 211 / 84 219 / 81 211 / 79 220 / 78 213 / 80 213 / 82 207 / 82 221 / 79
95 (35) 225 / 84 238 / 83 227 / 80 237 / 79 228 / 81 230 / 84 221 / 84 239 / 80
100 (38) 242 / 86 255 / 85 294 / 82 255 / 80 245 / 82 246 / 85 237 / 85 256 / 81
105 (41) 256 / 86 272 / 86 262 / 83 273 / 81 262 / 84 264 / 86 253 / 86 274 / 83
110 (43) 278 / 88 294 / 87 282 / 84 291 / 83 281 / 84 282 / 87 269 / 87 295 / 84
115 (45) 293 / 88 317 / 88 302 / 86 314 / 84 300 / 85 301 / 88 289 / 88 315 / 85
*Temperature of the air entering the outside coil.

Page 11
IV − MAINTENANCE
WARNING
Electric shock hazard. Can cause inju-
ry or death. Before attempting to per-
form any service or maintenance, turn
the electrical power to unit OFF at dis-
connect switch(es). Unit may have
multiple power supplies.
Maintenance and service must be performed by a qualified
installer or service agency. At the beginning of each cooling
season, the system should be checked as follows:
1. Clean and inspect outdoor coil. The coil may be flushed
with a water hose. Make sure power is off before clean-
ing.
The outdoor coil is protected by an inner mesh screen
and a wire cage (see figure 11).
9 pins used on
−048 and −060; 6
pins all others
PUSH PIN
MESH SCREEN
ÎÎÎÎÎÎÎÎÎÎÎÎÎÎ
ÎÎÎÎÎÎÎÎÎÎÎÎÎÎ
ÎÎÎÎÎÎÎÎÎÎÎÎÎÎ
ÎÎÎÎÎÎÎÎÎÎÎÎÎÎ
ÎÎÎÎÎÎÎÎÎÎÎÎÎÎ
ÎÎÎÎÎÎÎÎÎÎÎÎÎÎ
ÎÎÎÎÎÎÎÎÎÎÎÎÎÎ
FIGURE 11
If debris has collected between the mesh screen and
the coil and cannot be dislodged by spraying unpres-
surized water from inside coil surface to the outside, the
mesh may be removed by first removing the top of the
unit which will allow for removal of the wire cage.
Then, using pliers to grip the head of the push pins, pull
straight out to extract the push pins along one side of
the coil. If necessary, remove the push pins along the
back of the unit; it is usually unnecessary to fully re-
move the inner mesh screen.
Drape the mesh screen back and wash the coil. When
all the debris has been removed from the coil, reinstall
the mesh screen by positioning it in its original position
and reinserting the push pin. No tool is required to push
the pin back into the same slot in the fins.
If the push pin is loose and tends not to stay in place,
brush the fins with a fin brush (22 fins/in). Line up the
push pin a couple fins to the right or left of the original
hole and re−insert the pin.
2 − Condenser fan motor is prelubricated and sealed. No
further lubrication is needed.
3 − Visually inspect connecting lines and coils for evidence
of oil leaks.
4 − Check wiring for loose connections.
5 − Check for correct voltage at unit (unit operating).
6 − Check amp−draw condenser fan motor.
Unit nameplate _________ Actual ____________ .
NOTE − If owner complains of insufficient cooling, the unit
should be gauged and refrigerant charge checked. Refer
to section on refrigerant charging in this instruction.
Indoor Coil
1 − Clean coil, if necessary.
2 − Check connecting lines and coils for evidence of oil
leaks.
3 − Check the condensate line and clean it if necessary.
Indoor Unit
1 − Clean or change filters.
2 − Adjust blower speed for cooling. Measure the pressure
drop over the coil to determine the correct blower CFM.
Refer to the unit information service manual for pressure
drop tables and procedure.
3 − Belt Drive Blowers − Check belt for wear and proper ten-
sion.
4 − Check all wiring for loose connections
5 − Check for correct voltage at unit (blower operating).
6 − Check amp−draw on blower motor
Unit nameplate_________ Actual ____________.

Page 12
V − WIRING DIAGRAMS AND SEQUENCE OF OPERATION
13ACD
NOTE− The thermostat used may be electromechanical or electronic.
NOTE− Transformer in indoor unit supplies power (24 VAC) to the thermostat and outdoor unit controls.
COOLING:
1− Cooling demand initiates at Y1 in the thermostat.
2− 24VAC from indoor unit (Y1) energizes the TOC timed off control (if used) , which energizes contactor K1.
3− K1-1 N.O. closes, energizing compressor (B1) and outdoor fan motor (B4).
4 − Compressor (B1) and outdoor fan motor (B4) begin immediate operation..
END OF COOLING DEMAND:
5− Cooling demand is satisfied. Terminal Y1 is de-energized.
6− Compressor contactor K1 is de-energized.
7− K1-1 opens and compressor (B1) and outdoor fan motor (B4) are de-energized and stop immediately.