Page 1
©2006 Lennox Industries Inc.
Corp. 0625−L5
XC16
Service Literature
Revised 07−2006
XC16 SERIES UNITS
The XC16 is a high efficiency residential split−system condensing unit, which features a two speed scroll compressor
and R−410A refrigerant. XC16 units are available in 2, 3, 4
and 5 tons. XC16 units are rated for 230 volts only. Applications where supply voltage is less requires a hard start kit.
The series is designed for use with an expansion valve (approved for use with R−410A) in the indoor unit. This manual
is divided into sections which discuss the major components, refrigerant system, charging procedure, maintenance and operation sequence.
Information contained in this manual is intended for use by
qualified service technicians only. All specifications are subject to change.
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 qualified installer or service
agency.
WARNING
Warranty will be voided if covered equipment is removed from original installation site. Warranty will
not cover damage or defect resulting from:
Flood, wind, lightning, or installation and operation
in a corrosive atmosphere (chlorine, fluorine, salt,
recycled waste water, urine, fertilizers, or other damaging chemicals).
DANGER
Shock Hazard
Remove all power at disconnect
before removing access panel.
Single phase XC16 units use singlepole contactors. Potential
exists for electrical shock resulting
in injury or death.
Line voltage exist at all components
(even when unit is not in operation).
IMPORTANT
Operating pressures of this R−410A unit are higher
than pressures in R−22 units. Always use service
equipment rated for R410A.
TABLE OF CONTENTS
General Page 1. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Specifications / Electrical Data Page 2. . . . . . . . .
I Application Page 3. . . . . . . . . . . . . . . . . . . . . . . . .
II Unit Components Page 3. . . . . . . . . . . . . . . . . .
III Refrigeration System Page 11. . . . . . . . . . . . . . .
IV Charging Page 12. . . . . . . . . . . . . . . . . . . . . . . . .
V Service and Recovery Page 16. . . . . . . . . . . . . .
VI Maintenance Page 16. . . . . . . . . . . . . . . . . . . . . .
VII Wiring and Sequence of Operation Page 17. .
Page 2
SPECIFICATIONS
General
Model No. XC16−024 XC16−036 XC16−048 XC16−060
Data
Nominal Tonnage 2
3 4 5
Connections
Liquid line (o.d.) − in. 3/8 3/8 3/8 3/8
(sweat)
Suction line (o.d.) − in. 3/4
7/8 7/8 1−1/8
Refrigerant
1
R−410A charge furnished 7 lbs. 5 oz. 8 lbs. 9 oz. 11 lbs. 4 oz. 14 lbs. 2 oz.
Outdoor
Net face area − sq. ft. Outer coil 13.22 16.33 21.00 24.93
Coil
Inner coil 12.65
15.76 20.27 24.14
Tube diameter − in. 5/16 5/16 5/16 5/16
No. of rows 2 2 2 2
Fins per inch 22 22 22 22
Outdoor
Diameter − in. 18 22 22 26
Fan
No. of blades 3
4 4 3
Motor hp 1/10 1/6 1/4 1/3
Cfm 2320 3060 3955 4380
Rpm 1130 845 835 850
Watts 165 215 320 280
Shipping Data − lbs. 1 pkg. 208 238 268 323
ELECTRICAL DATA
Line voltage data − 60hz
4
230V−1ph
4
230V−1ph
4
230V−1ph
4
230V−1ph
3
Maximum overcurrent protection (amps) 20 35 45 55
2
Minimum circuit ampacity 13.6 22.0 28.2 33.9
Compressor Rated load amps 10.3 16.7 21.2 25.6
p
Locked rotor amps 52 82 96 118
Power factor 0.98 0.99 0.99 0.99
Outdoor Fan
Full load amps 0.7 1.1 1.7 1.8
Motor
Locked Rotor amps 2
2.1 3.1 2.9
OPTIONAL ACCESSORIES − must be ordered extra
Compressor Hard Start Kit 10J42
p
81J69
Compressor Low Ambient Cut−Off 45F08
Compressor Time−Off Control 47J27
Freezestat 3/8 in. tubing 93G35
5/8 in. tubing 50A93
Indoor Blower Relay 40K58
Low Ambient Kit 68M04
SignatureStatt Home Comfort Control 81M27
Refrigerant
Line Sets
L15−41−20
L15−41−30
L15−65−40
L15−65−50
L15−65−30
L15−65−40
L15−65−50
Field Fabricate
Time Delay Relay 58M81
NOTE − Extremes of operating range are plus 10% and minus 5% of line voltage.
1
Refrigerant charge sufficient for 15 ft. length of refrigerant lines.
2
Refer to National or Canadian Electrical Code manual to determine wire, fuse and disconnect size requirements.
3
HACR type breaker or fuse.
4
Hard start kit is required in applications where the supply voltage is less than 230V.
Page 3
I − APPLICATION
XC16 condensing units are available in 2, 3, 4 and 5 ton capacities. All major components (indoor blower and coil) must be
matched according to Lennox recommendations for the compressor to be covered under warranty. Refer to the Engineering Handbook for approved system matchups.
II − UNIT COMPONENTS
Unit components are illustrated in figure 1.
XC16 PARTS ARRANGEMENT
FIGURE 1
DUAL CAPACITOR
CONTACTOR
OUTDOOR FAN
COMPRESSOR
HIGH
PRESSURE
SWITCH
FILTER DRIER
LOW
PRESSURE
SWITCH
CAUTION
To prevent personal injury, or damage to panels, unit
or structure, be sure to observe the following:
While installing or servicing this unit, carefully stow
all removed panels out of the way, so that the panels
will not cause injury to personnel, nor cause damage
to objects or structures nearby, nor will the panels be
subjected to damage (e.g., being bent or scratched).
While handling or stowing the panels, consider any
weather conditions, especially windy conditions, that
may cause panels to be blown around and battered.
Remove the louvered panels as follows:
1 − Remove 2 screws, allowing the panel to swing open
slightly (see figure 2).
Detail
A
Detail C
Detail
B
FIGURE 2
Removing/Installing Louvered Panels
MAINTAIN MINIMUM PANEL ANGLE (AS CLOSE TO PARALLEL WITH THE UNIT
AS POSSIBLE) WHILE INSTALLING PANEL.
PREFERRED ANGLE
FOR INSTALLATION
Detail D
ROTATE IN THIS DIRECTION;
THEN DOWN TO REMOVE PANEL
SCREW
HOLES
ANGLE MAY BE TOO
EXTREME
HOLD DOOR FIRMLY TO THE HINGED
SIDE TO MAINTAIN
FULLY−ENGAGED TABS
LIP
IMPORTANT! Do not allow panels to hang on unit by top tab. Tab
is for alignment and not designed to support weight of panel.
Panel shown slightly rotated to allow top tab to exit (or enter) top
slot for removing (or installing) panel.
2 − Hold the panel firmly throughout this procedure. Ro-
tate bottom corner of panel away from hinge corner post
until lower 3 tabs clear the slots (see figure 2, Detail B).
3 − Move panel down until lip of upper tab clears the top slot
in corner post (see figure 2, Detail A).
Page 4
Position and Install PanelPosition the panel almost parallel with the unit (figure 2, Detail D) with the screw side" as
close to the unit as possible. Then, in a continuous motion:
Slightly rotate and guide the lip of top tab inward (figure 2,
Details A and C); then upward into the top slot of the
hinge corner post.
Rotate panel to vertical to fully engage all tabs.
Holding the panel’s hinged side firmly in place, close the
right−hand side of the panel, aligning the screw holes.
When panel is correctly positioned and aligned, insert the
screws and tighten.
A − Control Box (Figure 3)
XC16 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 cover. Field thermostat wiring is made to color-coded pigtail
connections.
ELECTROSTATIC DISCHARGE (ESD)
Precautions and Procedures
CAUTION
Electrostatic discharge can affect electronic components. Take precautions during unit installation
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 electrostatic charge by touching
hand and all tools on an unpainted unit surface before performing any service procedure.
FIGURE 3
DUAL CAPACITOR
(C12)
COMPRESSOR
CONTACTOR
(K1)
CONTROL BOX
GROUNDING
LUG
TIMED OFF
CONTROL.
(OPTION)
1 − Compressor Contactor (K1)
The compressor is energized by a single−pole contactor located in the control box. See figure 3. K1 is energized by the
indoor thermostat terminal Y1 (24V) when thermostat demand is present.
2 − Dual Capacitor (C12)
The compressor and fan in XC16 series units use permanent split capacitor motors. The capacitor is located inside the unit control box (see figure 3). 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. See side of capacitor for ratings.
3 − Start Kit (option)
The start kit consists of a potential relay K31 and start capacitor C7. The potential relay controls the operation of the
starting circuit. The relay is normally closed when contactor
K1 is de−energized. When K1 is energized, the compressor
immediately begins start up. K31 remains closed during
compressor start up and and start capacitor C7 remains in
the circuit. When compressor reaches approximately 75%
of its speed, K31 is energized. When K31 energizes, the
contacts open and start capacitor C7 is taken out of the circuit.
4 − Timed Off Control TOC (option)
The time delay is electrically connected between thermostat
terminal Y and the compressor contactor. Between cycles,
the compressor contactor is delayed for 5 minutes ± 2 min-
utes 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.
Page 5
B − Two−Stage Scroll Compressor (B1)
CAUTION
In order to avoid injury, take precaution when
lifting heavy objects.
FIGURE 1
TWO−STAGE MODULATED SCROLL
solenoid actuator coil
slider ring
The scroll compressor design is simple, efficient and requires few moving parts. A cutaway diagram of the scroll
compressor is shown in figure 1.The scrolls are located in
the top of the compressor can and the motor is located just
below. The oil level is immediately below the motor.
The scroll is a simple compression concept centered around
the unique spiral shape of the scroll and its inherent properties. Figure 2 shows the basic scroll form. Two identical
scrolls are mated together forming concentric spiral shapes
(figure 3 ). One scroll remains stationary, while the other is
allowed to orbit" (figure 4). Note that the orbiting scroll does
not rotate or turn but merely orbits" the stationary scroll.
FIGURE 2
SCROLL FORM
FIGURE 3
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
4 − 1). The centrifugal action of the orbiting scroll seals off the
flanks of the scrolls (figure 4 − 2). As the orbiting motion continues, the gas is forced toward the center of the scroll and the
gas pocket becomes compressed (figure 4 −3). When the
compressed gas reaches the center, it is discharged vertically into a chamber and discharge port in the top of the compressor (figure1). The discharge pressure forcing down on
the top scroll helps seal off the upper and lower edges (tips) of
the scrolls (figure 3 ). 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 center of the scroll and is discharged. If the compressor is replaced, conventional Lennox cleanup practices
must be used.
Due to its efficiency, the scroll compressor is capable of
drawing a much deeper vacuum than reciprocating compressors. Deep vacuum operation can cause internal fusite
arcing resulting in damaged internal parts and will result in
compressor failure. This type of damage can be detected
and will result in denial of warranty claims. The scroll compressor can be used to pump down refrigerant as long as
the pressure is not reduced below 7 psig.
The scroll compressors in all XC16 model units are designed for use with R410A refrigerant and operation at high
pressures. Compressors are shipped from the factory with
3MA (32MMMA) P.O.E. oil. See electrical section in this
manual for compressor specifications.
NOTE − During operation, the head of a scroll compressor
may be hot since it is in constant contact with discharge
gas.
Page 6
TWO−STAGE OPERATION
NOTE − During operation, the head of a scroll compressor
may be hot since it is in constant contact with discharge
gas.
The two−stage scroll compressor operates like any standard
scroll compressor with the exception the two−stage compressor modulates between first stage (low capacity
approximately 67%) and second stage (high capacity).
Modulation occurs when gas is bypassed through bypass
ports (figure 5 bypass ports open) in the first suction pocket.
This bypassing of gas allows the compressor to operate on
first stage (low capacity) if thermostat demand allows. Indoor thermostat setting will determine first or second stage
operation. The compressor will operate on first−stage until
demand is satisfied or the indoor temperature reaches the
thermostat set point calling for second−stage.
Second−stage (high capacity) is achieved by blocking the
bypass ports (figure 5 bypass ports closed) with a slider ring.
The slider ring begins in the open position and is controlled
by a 24VDC internal solenoid. On a Y2 call the internal solenoid closes the slider ring, blocking the bypass ports and
bringing the compressor to high capacity. Two−stage modulation can occur during a single thermostat demand as the
motor runs continuously while the compressor modulates
from first−stage to second− stage.
FIGURE 4
SCROLL
HOW A SCROLL WORKS
SUCTION
SUCTION
SUCTION
MOVEMENT OF ORBIT
STATIONARY SCROLL
ORBITING
CRESCENT
SHAPED GAS
POCKET
HIGH
PRESSURE
GAS
DISCHARGE
POCKET
FLANKS
SEALED BY
CENTRIFUGAL
FORCE
12
3
4
SUCTION
INTERMEDIATE
PRESSURE
GAS
SUCTION
POCKET
FIGURE 5
Bypass Ports
Closed
High Capacity
Bypass Ports
Open
67% Capacity
TWO STAGE MODULATION
Page 7
INTERNAL SOLENOID (L34)
The internal unloader solenoid controls the two−stage operation of the compressor by shifting a slide ring mechanism
to open two by−pass ports in the first compression pocket of
the scrolls in the compressor. The internal solenoid is activated by a 24 volt direct current solenoid coil. The coil
power requires 20VAC. The internal wires from the solenoid
in the compressor are routed to a 2 pin fusite connection on
the side of the compressor shell. The external electrical connection is made to the compressor with a molded plug assembly. This plug contains a full wave rectifier that converts
24 volt AC into 24 volt DC power to power the unloader solenoid. Refer to unit diagram for internal circuitry view of plug).
If it is suspect the unloader is not operating properly, check
the following
IMPORTANT
This performance check is ONLY valid on systems
that have clean indoor and outdoor coils, proper airflow over coils, and correct system refrigerant
charge. All components in the system must be functioning proper to correctly perform compressor modulation operational check. (Accurate measurements
are critical to this test as indoor system loading and
outdoor ambient can affect variations between low
and high capacity readings).
STEP 1 Confirm low to high capacity compressor operation
Tools required
Refrigeration gauge set
Digital volt/amp meter
Electronic temperature thermometer
On-off toggle switch
Procedure
1 − Turn main power "OFF" to outdoor unit.
2 − Adjust room thermostat set point above (heating opera-
tion on heat pump) or below (cooling operation) the
room temperature 5ºF.
3 − Remove control access panel. Install refrigeration
gauges on unit. Attach the amp meter to the common
(black wire) wire of the compressor harness. Attach
thermometer to discharge line as close as possible to
the compressor.
4 − Turn toggle switch "OFF" and install switch in series with
Y2 wire from room thermostat.
5 − Cycle main power "ON."
6 − Allow pressures and temperatures to stabilize before
taking any measured reading (may take up to 10 minutes).
NOTE − Block outdoor coil to maintain a minimum of 375 psig
during testing).
7 − Record all of the readings for the Y1 demand on table 1.
8 − Close switch to energize Y2 demand.
9 − Allow pressures and temperatures to stabilize before
taking any measured reading (this may take up to 10
minutes).
10 − Record all of the readings of Y2 demand on table 1.
NOTE − On new installations or installations that have
shut down for an extended period of time, if the compressor does not cycle from low stage to high stage on the
first attempt, it may be necessary to recycle the compressor back down to low stage and back up to high stage a
few times in order to get the bypass seals to properly seat
Compare Y1 readings with Y2 readings in table 1. Some
readings should be higher, lower or the same. If the readings follow what table 1 specifies, the compressor is operating and shifting to high capacity as designed. If the
readings do not follow what table 1 specifies, continue to
step 2 to determine if problem is with external solenoid
plug power.
Page 8
TABLE 1
Cooling Operation
Unit Readi
ngs
Y1 − 1st-Stage Expected Results Y2 − 2nd-Stage
Compressor
Voltage Same
Amperage Higher
Condenser Fan motor
Amperage Same or Higher
Temperature
Ambient Same
Outdoor Coil Discharge Air Higher
Compressor Discharge Line Higher
Indoor Return Air Same
Indoor Coil Discharge Air Lower
Pressures
Suction (Vapor) Lower
Liquid Higher
STEP 2 Confirm DC voltage output on compressor
solenoid plug
11 − Shut power off to outdoor unit.
12 − Supply 24 volts AC control voltage to the wire ends of
the full wave rectifier plug. Listen for a click" as the sole-
noid is energized. See figure 6.
compressor
solenoid fusite
terminals
compressor
fusite
terminals
meter
rectifier plug leads
apply 24vac
FIGURE 6
13 − Unplug the full wave rectifier plug from the fusite con-
nection on the compressor.
14 − Turn the low voltage power back onto the unit. Supply
24VAC to the wires of the full wave rectifier plug. Set volt
meter to DC volts and measure the DC voltage at the fe-
male connector end of the full wave rectifier plug. The
DC voltage reading should be 1.5 to 3 volts lower than
the input voltage to the plug wire leads. (EX: Input volt-
age is 24VAC output voltage is 22VDC). See figure 7.
meter
rectifier plug leads
compressor
fusite
terminals
solenoid
fusite
terminals
compressor
apply 24vac
FIGURE 7
If the above checks verify that the solenoid plug is providing power to cycle into high capacity operation, continue
to step 3 to determine if problem is with solenoid coil in
compressor
STEP 3 Confirm internal unloader solenoid has proper resistance
15 − Shut all power off to unit (main and low voltage)
16 − Unplug the molded plug from the compressor solenoid
2−pin fusite.
17 − Using a volt meter set on the 200 ohm scale
meter
rectifier plug leads
compressor
fusite
terminals
solenoid
fusite
terminals
compressor
FIGURE 8
Replace the Compressor under these conditions:
Bad Solenoid
a. Measure the resistance at the 2−pin fusite. See figure 8.
The resistance should be 32 to 60 ohms depending on
compressor temperature. If no resistance replace compressor.
b. Measure the resistance from each fusite pin to ground.
There should not be continuity to ground. If solenoid coil
is grounded, replace compressor.
Good Solenoid
a. Seals not shifting, replace compressor
b. Slider ring not shifting, replace compressor.
Page 9
C − Drier
A filter drier designed for all XC16 model units is factory
installed in the liquid line. The filter drier is designed to remove moisture and foreign matter, which can lead to compressor failure.
Moisture and / or Acid Check
Because POE oils absorb moisture, the dryness of the
system must be verified any time the refrigerant system
is exposed to open air. A compressor oil sample must be
taken to determine if excessive moisture has been
introduced to the oil. Table 2 lists kits available from Lennox
to check POE oils.
If oil sample taken from a system that has been exposed to
open air does not test in the dry color range, the filter drier
MUST be replaced.
IMPORTANT
Replacement filter drier MUST be approved for
R−410A refrigerant and POE application.
Foreign Matter Check
It is recommended that a liquid line filter drier be replaced
when the pressure drop across the filter drier is greater than
4 psig.
TABLE 2
KIT CONTENTS TUBE SHELF LIFE
10N46 − Refrigerant Analysis Checkmate−RT700
10N45 − Acid Test Tubes Checkmate−RT750A (three pack)
2 − 3 years @ room temperature. 3+
years refrigerated
10N44 − Moisture Test Tubes
Checkmate − RT751 Tubes (three
pack)
6 − 12 months @ room temperature. 2
years refrigerated
74N40 − Easy Oil Test Tubes
Checkmate − RT752C Tubes (three
pack)
2 − 3 years @ room temperature. 3+
years refrigerated
74N39 − Acid Test Kit Sporlan One Shot − TA−1
FIGURE 9
1− Shut off power to unit.
2− Remove high pressure switch from fitting next to filter drier.
(A schrader core is located under the high pressure switch).
3− Install high pressure gauge hose onto high pressure switch fitting.
4− Turn power on to unit and turn room thermostat to call for cooling.
5− Record pressure reading on gauge.
6− Remove hose from high pressure fitting and install on liquid line valve.
7− Read liquid line valve pressure.
8− High pressure fitting pressure − liquid line valve pressure = filter drier
pressure drop.
9− If pressure drop is greater than 4 psig replace filter drier. See figure 10.
10− Re−install high pressure switch.
MEASURING FILTER DRIER PRESSURE DROP
FIGURE 10
REPLACING FILTER DRIER
1− Recover all refrigerant from unit.
2− Remove original filter drier.
3− Install new filter drier in existing location or alternate location as
shown. Proper brazing procedures should be followed.
4− Evacuate system. See section IV − part B − .
5− Recharge system. See section IV − part C − .
Page 10
D − Condenser Fan Motor (B4)
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 specifications for condenser fans used in XC16’s.
Access to the condenser fan motor on all units is gained
by removing the four screws securing the fan assembly.
See figure 4. The grill fa n ass e mbly ca n be removed from
the cabinet as one piece. See figure 5. The condenser fan
motor is removed from the fan guard by removing the four
nuts found on top of the grill. See figure 5 if condenser fan
motor replacement is necessary.
Make sure all power is disconnected before
beginning electrical service procedures.
DANGER
FIGURE 4
Remove
screws
Remove
screws
ALIGN FAN HUB FLUSH WITH END OF SHAFT
FIGURE 5
E − Low Pressure Switch (S87)
All XC16 units are equipped with an auto-reset, single-pole/
single-throw low pressure switch is located in the vapor line.
This switch shuts off the compressor by de−energizing K1
when vapor line pressure drops below the factory setting.
The switch is closed during normal operating pressure conditions and is permanently adjusted to trip (open) at 40 +
5
psi. The switch automatically resets when vapor line pressure rises above 90 +
5 psi.
F − High Pressure Switch (S4)
XC16 units are equipped with a high pressure switch that is
located in the liquid line of the compressor. The switch
(SPST, manual reset, normally closed) removes power from
the compressor contactor control circuit when discharge
pressure rises above factory setting at 590 +
10 psi.
G − Crankcase Heater (HR1) &
Thermostat (S40) −048 and −060 units only
Compressor in the XC16−048 and −060 units are equipped
with a 70 watt, belly band type crankcase heater. HR1 prevents liquid from accumulating in the compressor. HR1 is
controlled by a thermostat located on the liquid line. When liquid line temperature drops below 50° F the thermostat closes
energizing HR1. The thermostat will open, de−energizing
HR1 once liquid line temperature reaches 70° F .
Page 11
III − REFRIGERANT SYSTEM
A − Plumbing
Field refrigerant piping consists of liquid and suction lines
from the condensing unit (sweat connections) to the indoor
evaporator coil (sweat connections). Use Lennox L15
(sweat) series line sets as shown in table 1.
TABLE 1
Unit
Liquid
Line
Suction
Line
L15 Line Sets
−024,
3/8 in.
(10 mm)
3/4 in.
(19 mm)
L15−41
15 ft. − 50 ft.
(4.6 m − 15 m)
−036,
−048
3/8 in.
(10 mm)
7/8 in.
(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)
Field
Fabricated
The liquid line and vapor line service valves (figures 6 and 7)
and gauge ports are accessible from the outside of the unit.
Use the service ports for leak testing, evacuating, charging
and checking charge.
Each valve is equipped with a service port which has a factory−installed Schrader valve. A service port cap protects the
Schrader valve from contamination and serves as the primary leak seal. Service valves are not rebuildable. If a valve
has failed, you must replace it.
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 − Using the adjustable wrench to keep the valve station-
ary, 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 3/8" line
sizes or a 5/16" extension for large 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 − Using the adjustable wrench to keep the valve station-
ary, 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 3/8" line
sizes or a 5/16" extension for large line sizes.
3 − Replace the stem cap. Tighten finger tight, then tighten an
additional 1/6 turn.
NOTE − Stem cap must be replaced to help prevent
valve leakage.
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 6
Vapor Line Ball Valve – 5 Ton Units Only
Vapor line service valves function the same way as the other
valves, the difference is in the construction. A ball valve is
illustrated in figure 7.
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.
Page 12
Ball Valve (Valve Open)
FIGURE 7
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
IV − CHARGING
WARNING
R−410A refrigerant can be harmful if it is inhaled.
R−410A refrigerant must be used and recovered responsibly.
Failure to follow this warning may result in personal
injury or death.
A − Leak Testing
After the line set has been connected to the indoor and outdoor units, check the line set connections and indoor unit
for leaks.
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.
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
could result in personal injury or death.
WARNING
Danger of explosion: Can cause equipment damage,
injury or death. When using a high pressure gas such
as dry nitrogen to pressurize a refrigeration or air conditioning system, use a regulator that can adjust the
pressure from 0 to 450 psig ( 3103 kPa).
Using an Electronic Leak Detector
1 − Connect a cylinder of R−410A to the center port of the
manifold gauge set. Connect manifold gauge to service
valve port.
2 − With both manifold valves closed, open the valve on the
R−410A cylinder.
3 − Open the high pressure side of the manifold to allow the
R−410A into the line set and indoor unit. Weigh in a trace
amount of R−410A. [A trace amount is a maximum of 2
ounces (57 g) or 3 pounds (31 kPa) pressure.] Close the
valve on the R−410A cylinder and the valve on the high
pressure side of the manifold gauge set. Disconnect the
R−410A 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 manifold 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 R−410A
mixture. Correct any leaks and recheck.
B − Evacuating
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 piping and compressor parts.
NOTE − This evacuation process is adequate for a new
installation with clean and dry lines. If excessive moisture is present, the evacuation process may be required
more than once.
Page 13
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.
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 determine 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 pressure in a
vacuum is equal to atmospheric pressure minus 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 cylinder with pressure regulator set to 150 psig (1034 kPa)
and purge the air from the hose with nitrogen. 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 compressors 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 vacuum pump and connect it to an upright cylinder of R−410A
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 R−410A cylinder and remove the manifold gauge
set.
C − Charging
NOTES −
R−410A refrigerant cylinders are rose−colored. Re-
frigerant should be added through the vapor valve
in the liquid state.
Certain R−410A cylinders are identified as being
equipped with a dip tube. These allow liquid refrigerant to be drawn from the bottom of the cylinder
without inverting the cylinder. DO NOT turn this type
cylinder upside−down to draw refrigerant.
IMPORTANT
Use table 6 to perform maintenance checks. Table 6 is
not a procedure for charging the system. Minor variations in these pressures may be due to differences in
installations. Significant deviations could mean that
the system is not properly charged or that a problem
exists with some component in the system.
This system is charged with R−410A refrigerant which operates at much higher pressures than R−22. The installed liquid line filter drier is approved for use with R−410A. Do not
replace it with components designed for use with R−22. This
unit is NOT approved for use with coils which use capillary
tubes as a refrigerant metering device.
Factory Charge
Units are factory charged with the amount of R−410A refrigerant indicated on the unit rating plate. This charge is based
on a matching indoor coil and outdoor coil with 15 ft. (4.6 m)
line set. For varying lengths of line set, refer to table 2 for refrigerant charge adjustment.
Page 14
TABLE 2
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)
*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.
IMPORTANT
Mineral oils are not compatible with R−410A. If oil
must be added, it must be a polyol ester oil.
The compressor is charged with sufficient polyol ester oil for approved line set lengths.
Units Delivered Void of Charge
If the system is void of refrigerant, clean the system using
the procedure described below.
1 − Use dry nitrogen to pressurize the system and check for
leaks. Repair leaks, if possible.
2 − Evacuate the system to remove as much of the moisture
as possible. Use dry nitrogen to pressurize the system
and check for leaks. Repair leaks, if possible.
3 − Use dry nitrogen to break the vacuum and install the pro-
vided filter drier in the system.
4 − Evacuate the system again. Then, weigh the appropriate
amount of R−410A refrigerant (listed on unit nameplate)
into the system.
5 − Monitor the system to determine the amount of moisture
remaining in the oil. Use test kit 10N46 to verify that the
moisture content is within the kit’s dry color range. It
may be necessary to replace the filter drier several
times to achieve the required dryness level.
If system dryness is not verified, the compressor
will fail in the future.
Checking Charge
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 ambient 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 R−410A .
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 − Record outdoor ambient temperature using a digital ther-
mometer.
5 − When the heating demand has been satisfied, switch the
thermostat to cooling mode with a set point of 68F
(20C). When pressures have stabilized, use a digital
thermometer to record the liquid line temperature.
6 − The outdoor temperature will determine which charging
method to use. Proceed with the appropriate charging
procedure.
Charge Using Weigh-in Method TXV Systems
Outdoor Temp. < 65ºF (18ºC)
If the system is void of refrigerant, or if the outdoor ambient
temperature is cool, first, locate and repair any leaks and
then weigh in the refrigerant charge into the unit.
1 − Recover the refrigerant from the unit.
2 − Conduct leak check; evacuate as previously outlined.
3 − Weigh in the unit nameplate charge. If weighing facilities
are not available or if charging the unit during warm
weather, use one of the following procedures.
Charge Using the Subcooling Method –
Outdoor Temperature <
65°F (18°C)
When the outdoor ambient temperature is below 65°F
(18°C), use the subcooling method to charge the unit. Values from (table 3) are used for this procedure.
If necessary, restrict air flow through the outdoor coil to
achieve pressures in the 325−375 psig (2240−2585 kPa)
range. Higher pressures are necessary for checking the
charge. Block equal sections of air intake panels and move
obstructions sideways until the liquid pressure is in the
325−375 psig (2240−2585 kPa) range. See figure 11.
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 11
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 (table 3) 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.
Page 15
5 − Compare the subcooling value with those in table 4. If
subcooling is greater than shown, recover some refrigerant. If subcooling is less than shown, add some refrigerant. Be aware of the R−410A refrigerant cylinder. It will
be light maroon−colored. Refrigerant should be added
through the vapor line valve in the liquid state.
TABLE 3
R−410A Temperature (°F) − Pressure (Psig)
°F Psig °F Psig °F Psig °F Psig
32 100.8 64 181.6 96 299.4 126 451.8
34 105.0 66 187.7 98 308.2 128 463.5
36 109.2 68 194.1 100 317.2 130 475.6
38 113.6 70 200.6 102 326.4 132 487.8
40 118.0 72 207.2 104 335.7 134 500.2
42 122.6 74 214.0 106 345.3 136 512.9
44 127.3 76 220.9 108 355.0 138 525.8
46 132.2 78 228.0 11 0 365.0 140 539.0
48 137.1 80 235.3 11 2 375.1 142 552.3
50 142.2 82 242.7 11 4 385.4 144 565.9
52 147.4 84 250.3 11 6 396.0 146 579.8
54 152.8 86 258.0 11 8 406.7 148 593.8
56 158.2 88 266.0 120 417.7 150 608.1
58 163.9 90 274.1 122 428.8 152 622.7
60 169.6 92 282.3 124 440.2 154 637.5
62 195.5 94 290.8 126 451.8 156 652.4
TABLE 4
XC16 Subcooling Values for Charging
Saturation Temperature
Liquid Line Temperature
=
Subcooling Value
Model −024 −036 −048 −060
°F (°C)* 5 (2.8) 6 (3.3) 6 (3.3) 9 (5)
*F: +/−1.0°; C: +/−0.5°
Charge Using the Approach Method,
TXV Systems
Outdoor Temperature > 65ºF (18ºC)
The following procedure is intended as a general guide and is
for use on expansion valve systems only. For best results, indoor temperature should be 70°F (21°C) to 80°F (26°C).
Monitor system pressures while charging.
1 − Record outdoor ambient temperature using a digital
thermometer.
2 − Attach high pressure gauge set and operate unit for sev-
eral minutes to allow system pressures to stabilize.
3 − Compare stabilized pressures with those provided in
table 6, Normal Operating Pressures." Pressures higher than those listed indicate that the system is overcharged. Pressures lower than those listed indicate that
the system is undercharged. A temperature/pressure
chart for R−410A refrigerant is provided in table 3 for
your convenience. Verify adjusted charge using the approach method.
NOTE − Use the same digital thermometer you used to
check the outdoor ambient temperature to check the liquid line temperature.
4 − The difference between the ambient and liquid tempera-
tures should match values given in table 5. If the values
don’t agree with the those in table 5, add refrigerant to
lower the approach temperature, or recover refrigerant
from the system to increase the approach temperature.
Be aware of the R−410A refrigerant cylinder. It will be
light maroon−colored. Refrigerant should be added
through the vapor valve in the liquid state.
TABLE 5
XC16 Approach Values for Charging
Liquid Line Temperature
Outdoor Temperature
=
Approach Temperature
Model −024 −036 −048 −060
°F (°C)* 8 (4.4) 10 (5.6) 8 (4.4) 4 (2.2)
*F: +/−1.0°; C: +/−0.5°
IMPORTANT
Table 6 is not a procedure for charging the system but
may be used to perform maintenance checks. Minor
variations in these pressures may be due to differences 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 6
Normal Operating Pressures In psig
(liquid +/− 10 and vapor+/− 5 PSIG)*
Temp. of
air enter-
−024 −036 −048 −060
air enter
ing outdoor coil
5F (5C)
Liquid
Suction
Liquid
Suction
Liquid
Suction
Liquid
Suction
First Stage (Low Capacity)
65 (18.3) 223 141 227 137 224 142 215 136
75 (23.9) 256 143 261 142 258 144 250 139
85 (29.4) 297 145 302 145 299 146 291 142
95 (35.0) 341 148 347 148 345 148 337 144
105 (40.6) 389 150 396 150 395 150 388 146
115 (46.1) 443 153 452 154 450 153 444 148
Second Stage (High Capacity)
65 (18.3) 232 140 244 132 235 135 220 130
75 (23.9) 268 143 278 139 269 137 256 133
85 (29.4) 310 145 321 142 313 139 299 136
95 (35.0) 356 147 368 144 361 141 347 138
105 (40.6) 405 149 419 147 412 143 402 141
115 (46.1) 459 152 476 150 471 146 462 143
*These are typical pressures only. Indoor indoor match up, indoor air quality, and indoor load will cause the pressures to vary.
Page 16
V − SERVICE AND RECOVERY
WARNING
Polyol ester (POE) oils used with R−410A refrigerant
absorb moisture very quickly. It is very important
that the refrigerant system be kept closed as much
as possible. DO NOT remove line set caps or service
valve stub caps until you are ready to make connections.
IMPORTANT
USE RECOVERY MACHINE RATED FOR R−410A
REFRIGERANT.
If the XC16 system must be opened for any kind of service,
such as compressor or drier replacement, you must take extra precautions to prevent moisture from entering the system. The following steps will help to minimize the amount of
moisture that enters the system during recovery of R−410A.
1 − Use a regulator−equipped nitrogen cylinder to break the
system vacuum. Do not exceed 5 psi. The dry nitrogen
will fill the system, purging any moisture.
2 − Remove the faulty component and quickly seal the sys-
tem (using tape or some other means) to prevent addi-
tional moisture from entering the system.
3 − Do not remove the tape until you are ready to install new
component. Quickly install the replacement compo-
nent.
4 − Evacuate the system to remove any moisture and other
non−condensables.
Any time the XC16 sealed system is opened, the drier
must be replaced and the system must be evacuated.
Any moisture not absorbed by the polyol ester oil can be removed by evacuation. Moisture that has been absorbed by
the compressor oil can be removed by replacing the drier.
IMPORTANT
Evacuation of system only will not remove moisture
from oil. Drier must be replaced to eliminate moisture from POE oil.
VI − MAINTENANCE
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.
At the beginning of each cooling season, the system should
be serviced. In addition, the system should be cleaned as
follows:
A − Outdoor Unit
1 − Clean and inspect the outdoor coil. The coil may be
flushed with a water hose. Ensure the power is turned
off before you clean the coil.
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.
B − 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.
C − 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 17
VII − WIRING DIAGRAMS AND SEQUENCE OF OPERATION
Page 18
SERVICE NOTES
Page 19
SERVICE NOTES
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