Lennox XP19-024, XP19-036, XP19-048, XP19-060 Instruction Manual
Page 1
© 2005 Lennox Industries Inc.
Corp. 0510−L4
XP19
Service Literature
Revised 06−2008
XP19 SERIES UNITS
The XP19 is a high efficiency residential split−system heat
pump unit, which features a two−step scroll compressor
and R410A refrigerant. XP19 units are available in 2, 3 , 4
and 5 ton sizes. The series is designed for use with an expansion valve only (approved for use with R410A) 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.
CAUTION
Physical contact with metal edges and corners while
applying excessive force or rapid motion can result
in personal injury. Be aware of, and use caution when
working nearby these areas during installation or
while servicing this equipment.
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.
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.
DANGER
Shock Hazard
Remove all power at disconnect be-
fore removing access panel.
XP19 units use single-pole contactors. Potential exists for electrical
shock resulting in injury or death.
Line voltage exists at all components
(even when unit is not in operation).
Table of Contents
General 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Specifications / Electrical Data 2. . . . . . . . . . . . . . . . . .
I Application 3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
II Unit Components 3. . . . . . . . . . . . . . . . . . . . . . . . . . . .
III Refrigerant System 18. . . . . . . . . . . . . . . . . . . . . . . . . .
IV Charging 20. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
V Service and Recovery 24. . . . . . . . . . . . . . . . . . . . . . . .
VI Maintenance 24. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
VIIBrazing Procedure 24. . . . . . . . . . . . . . . . . . . . . . . . . .
VIII Diagrams and Operating Sequence 25. . . . . . . . . .
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SPECIFICATIONS
General
Model No. XP19−024 XP19−036 XP19−048 XP19−060
Data
Nominal Tonnage (kW) 2 (7.0)
3 (10.6) 4 (14.1) 5 (17.6)
Connections
Liquid line (o.d.) − in. (mm) 3/8 (9.5) 3/8 (9.5) 3/8 (9.5) 3/8 (9.5)
(sweat)
Vapor line (o.d.) − in. (mm) 7/8 (22.2)
7/8 (22.2) 7/8 (22.2) 1−1/8 (28.6)
Refrigerant
1
R−410A charge furnished 12 lbs. 0 oz. (5.4
kg)
12 lbs. 5 oz. (5.6
kg)
13 lbs. 8 oz. (6.1
kg)
16 lbs. 5 oz. (7.4
kg)
Outdoor
Net face area − sq. ft. (m2) Outer coil 20.50 (1.90) 20.50 (1.90) 26.92 (2.50) 26.92 (2.50)
Coil
Inner coil 19.86 (1.85)
19.86 (1.85) 26.07 (2.42) 26.07 (2.42)
Tube diameter − in. (mm) 5/16 (0.52) 5/16 (0.52) 5/16 (0.52) 5/16 (0.52)
No. of rows 2 2 2 2
Fins per inch (m) 22 (866) 22 (866) 22 (866) 22 (866)
Outdoor
Diameter − in. (mm) 26 (660) 26 (660) 26 (660) 26 (660)
Fan
No. of blades 3
3 3 3
Motor hp (W) 1/3 (249) 1/3 (249) 1/3 (249) 1/3 (249)
Cfm (L/s) 1st stage 2500 (1180) 2500 (1180) 2800 (1320) 2800 (1320)
2nd stage 2500 (1180) 2800 (1320) 3400 (1605) 3400 (1605)
Rpm − 1st stage 700 700 700 700
2nd stage 700 820 820 820
Watts − 1st stage 70 70 150 150
2nd stage 70 105 220 220
Shipping Data − lbs. (kg) 1 pkg. 304 (138) 315 (143) 352 (160) 387 (176)
ELECTRICAL DATA
Line voltage data − 60hz 208/230V−1ph 208/230V−1ph 208/230V−1ph 208/230V−1ph
3
Maximum overcurrent protection (amps) 25 40 50 60
2
Minimum circuit ampacity 15.7 23.7 29.3 34.9
Compressor
Rated load amps 10.3 16.7 21.2 25.7
p
Locked rotor amps 52 82 96 118
Power factor 0.98 0.98 0.98 0.98
Outdoor Coil
Fan Motor
Full load amps 2.8 2.8 2.8 2.8
OPTIONAL ACCESSORIES − must be ordered extra
Compressor Hard Start Kit
10J42
p
81J69
Compressor Low Ambient Cut−Off 45F08
Freezestat
3/8 in. tubing 93G35
1/2 in. tubing 39H29
5/8 in. tubing 50A93
Indoor Blower Relay 40K58
Low Ambient Kit 68M04
Monitor Kit − Service Light 76F53
Mounting Base 69J07
Outdoor
Thermostat 56A87
Thermostat
Mounting Box − US 31461
Kit
Canada 33A09
SignatureStatt Home Comfort Control 81M28
Refrigerant
Line Sets
L15−65−15
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. (4.6 m) 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.
Page 3
I−APPLICATION
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. A
misapplied system will cause erratic operation and can result in early compressor failure.
II−Unit Components
Remove 4 screws to
remove panel for
accessing compressor
and controls.
Install by positioning
panel with holes
aligned; install screws
and tighten.
FIGURE 1
Access Panel
Removing Access Panels
Remove and reinstall the access panel as described in figure 1.
Remove the louvered panels as follows:
1−. Remove 2 screws, allowing the panel to swing open
slightly.
2−. Hold the panel firmly throughout this procedure.
Rotate 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).
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.
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.
Page 4
FIGURE 3
XP19 PARTS ARRANGEMENT
OUTDOOR FAN
COMPRESSOR
CONTACTOR
DEFROST
CONTROL
LSOM
LOW PRESSURE
SWITCH
HIGH PRESSURE
SWITCH
DRIER
REVERSING
VALV E
CAPACITOR
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.
A−Two−Stage Scroll Compressor (B1)
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 5 shows the basic scroll form. Two identical scrolls are mated together forming concentric spiral
shapes (figure 6). One scroll remains stationary, while the
other is allowed to orbit" (figure 7). Note that the orbiting
scroll does not rotate or turn but merely orbits" the stationary scroll.
FIGURE 4
TWO−STAGE MODULATED SCROLL
slider ring
solenoid actuator coil
FIGURE 5
SCROLL FORM
FIGURE 6
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 7 − 1). The centrifugal action of the orbiting scroll
seals off the flanks of the scrolls (figure 7 − 2). As the orbiting
motion continues, the gas is forced toward the center of the
scroll and the gas pocket becomes compressed (figure 7
−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 7 − 4). The discharge pressure
forcing down on the top scroll helps seal off the upper and
lower edges (tips) of the scrolls (figure 6). During a single orbit, several pockets of gas are compressed simultaneously
providing smooth continuous compression.
Page 5
The scroll compressor is tolerant to the effects of liquid re-
turn. 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.
Due to its efficiency, the scroll compressor is capable of
drawing a much deeper vacuum than reciprocating com-
pressors. 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 com-
pressor can be used to pump down refrigerant as long as
the pressure is not reduced below 7 psig.
NOTE − During operation, the head of a scroll compressor
may be hot since it is in constant contact with discharge
gas.
The scroll compressors in all XP19 model units are de-
signed 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.
TWO−STAGE OPERATION
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 8 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 8 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 inter-
nal 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 7
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
Page 6
FIGURE 8
Bypass Ports
Closed
High Capacity
Bypass Ports
Open
Low Capacity
TWO−STAGE MODULATION
INTERNAL SOLENOID (L34)
The internal unloader solenoid controls the two−stage op-
eration of the compressor by shifting a slide ring mecha-
nism to open (low capacity) or close (high capacity), 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 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. The molded plug receives 24
volt DC power from the LSOM II.
If it is suspected 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 op-
eration 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 table1 specifies, continue to
step 2 to determine if problem is with external solenoid
plug power.
Page 7
TABLE 1
Compressor Operation
Unit Readings
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 in Cooling
Lower in Heating
Compressor Discharge Line Higher
Indoor Return Air Same
Indoor Coil Discharge Air Lower in Cooling
Higher in Heating
Pressures
Suction (Vapor) Lower
Liquid Higher
STEP 2 Confirm DC voltage output on compressor
solenoid plug
1−. Shut power off to the outdoor unit.
2−. Insert lead wires from voltmeter into back of the red
and black wire plug jack that feeds power to compressor solenoid coil. Set voltmeter to DC volt scale to read
DC voltage output from LSOM II plug. See figure 9.
FIGURE 9
3−. Apply a Y1 and Y2 demand from the indoor thermostat
to the LSOM II.
4−. Turn power back on to unit.
5−. Compressor should cycle ON" when Y1 is calling.
6−. With Y2 calling, 5 seconds after compressor cycles
ON", LSOM II will output 24 volt DC signal to the compressor solenoid plug. Once the solenoid has pulled in,
the LSOM II will reduce the DC voltage to a pulsating
6 to 18 volt DC output to the solenoid to allow the solenoid to remain energized.
IMPORTANT
When checking compressor for two−stage operation,
always cycle Y1 to Y2 from terminals on the LSOMII
or room thermostat connections. DO NOT cycle second stage (Y2) of compressor by unplugging the
24VDC solenoid LSOM II end of plug. The LSOM II will
only output a 6 to 18VDC signal which will be insufficient voltage to pull the solenoid coil in for second
stage.
If compressor solenoid is still not shifting to high capacity, this check will verify that DC power is being fed from
the LSOM II.
7−. Shut power off to unit (main and low voltage)
8−. Unplug the 2 pin solenoid plug from the fusite connec-
tion on the compressor and the plug end from the
LSOM II.
9−. Using an OHM meter, check for continuity on the plug
harness wire ends (red to red, black to black). Wires
should have continuity between same colors and no
continuity between opposite color wires.
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
1−. Shut all power off to unit (main and low voltage)
2−. Unplug the molded plug from the compressor solenoid
2−pin fusite.
3−. Using a volt meter set on the 200 ohm scale
Replace the Compressor under these conditions:
Page 8
Bad Solenoid
a. Measure the resistance at the 2−pin fusite. 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.
B−Contactor (K1)
The compressor is energized by a contactor located in the
control box. All XP19 units are single phase and use single−
pole contactors.
C−Low Pressure Switch (S87)
The XP19 is equipped with an auto−reset low pressure
switch which is located on the suction line. The switch shuts
off the compressor when the suction pressure falls below
the factory setting. This switch is ignored during the first 90
seconds of compressor start up, during defrost operation,
90 seconds after defrost operation, during test mode and
when the outdoor temperature drops below 15°F.
The switch closes when it is exposed to 55 psig and opens
at 25 psig. It is not adjustable.
D−High Pressure Switch (S4)
IMPORTANT
Pressure switch settings for R410A refrigerant will
be significantly higher than units with R22.
An auto-reset, single-pole/single-throw high pressure switch
is located in the liquid line. This switch shuts off the compressor when liquid line pressure rises above the factory setting.
The switch is normally closed and is permanently adjusted to
trip (open) at 590 +
15 psi and close at 418 + 15 psi. See fig-
ure 3 for switch location.
E−Capacitor (C12)
The compressor in XP19−024, −036, −048 and −060 units
use a permanent split capacitor (see unit wiring diagram).
The capacitor is located inside the unit control box. Ratings
are on capacitor side.
F−Condenser Fan with
Variable Speed Motor(B4)
The variable speed condenser fan motor (figure 10) used in all
units is a three-phase, electronically controlled d.c. brushless
motor (controller converts single phase a.c. to three phase
d.c.), with a permanent-magnet-type rotor, manufactured by
GE. Because this motor has a permanent magnet rotor it does
not need brushes like conventional D.C. motors. The motors
consist of a control module and motor . Internal components
are shown in figure 11. The stator windings are split into three
poles which are electrically connected to the controller. This arrangement allows motor windings to be turned on and off in
sequence by the controller.
The controller is primarily an a.c. to d.c. converter. Converted d.c. power is used to drive the motor. The controller contains a microprocessor which monitors varying
conditions inside the motor (such as motor workload).
The controller uses sensing devices to know what position
the rotor is in at any given time. By sensing the position of
the rotor and then switching the motor windings on and off
in sequence, the rotor shaft turns the blower.
VARIABLE SPEED CONDENSER FAN MOTOR
FIGURE 10
RED
YELLOW
BLACK
RED
BLUE
motor
control module
BLOWER MOTOR COMPONENTS
FIGURE 11
STATOR
(WINDINGS)
OUTPUT
SHAFT
BEARING
ROTOR
Internal Operation
The condenser fan motor is a variable speed motor with RPM
settings at 700 (Y1) and 820 (Y2). The variation in speed is
accomplished each time the controller switches a stator winding (figure10) on and off, it is called a pulse." The length of
time each pulse stays on is called the pulse width." By varying the pulse width the controller varies motor speed (called
pulse-width modulation"). This allows for precise control of
motor speed and allows the motor to compensate for varying
load conditions as sensed by the controller. In this case, the
controller monitors the static workload on the motor and varies motor rpm in order to maintain constant airflow (cfm).
Motor rpm is continually adjusted internally to maintain
constant static pressure against the fan blade. The controller monitors the static work load on the motor and motor
amp-draw to determine the amount of rpm adjustment.
Blower rpm is adjusted internally to maintain a constant
cfm. The amount of adjustment is determined by the incremental taps which are used and the amount of motor loading sensed internally. The motor constantly adjusts rpm to
maintain a specified cfm.
Page 9
Initial Power Up
When line voltage is applied to the motor, there will be a
large inrush of power lasting less than 1/4 second. This inrush charges a bank of DC filter capacitors inside the controller. If the disconnect switch is bounced when the disconnect is closed, the disconnect contacts may become
welded. Try not to bounce the disconnect switch when applying power to the unit.
The DC filter capacitors inside the controller are connected
electrically to the speed tap wires. The capacitors take
approximately 5 minutes to discharge when the disconnect
is opened. For this reason it is necessary to wait at least 5
minutes after turning off power to the unit before attempting
to service motor.
DANGER
Disconnect power from unit and wait at
least five minutes to allow capacitors
to discharge before attempting to service motor. Failure to wait may cause
personal injury or death.
Motor Start-Up
At start-up, the motor may gently rock back and forth for a
moment. This is normal. During this time the electronic
controller is determining the exact position of the rotor.
Once the motor begins turning, the controller slowly
eases the motor up to speed (this is called soft-start").
The motor may take as long as 10-15 seconds to reach
full speed. If the motor does not reach 200rpm within 13
seconds, the motor shuts down. Then the motor will immediately attempt a restart. The shutdown feature provides protection in case of a frozen bearing or blocked
fan blade. The motor may attempt to start eight times. If
the motor does not start after the eighth try, the controller
locks out. Reset controller by momentarily turning off
power to unit.
Troubleshooting
If first or second stage thermostat call for cool is present
and the variable speed condenser fan motor does not energize, check voltage at the breaker box. If voltage is present
do the following and reference figure 12.
1− Check for 240 volts between the compressor RED wi-
res.
2− Initiate a first stage call for cool. Check for 24 volts be-
tween the fan motor YELLOW wire and fan motor
BLACK wire.
3− Initiate a second stage call for cool. Check for 24 volts
between the fan motor YELLOW wire and fan motor
BLACK wire, then check for 24 volts between the fan
motor BLUE wire and fan motor BLACK.
4− Repeat steps 1 and 2 with a HEAT call.
FIGURE 12
RED
RED
240V
YELLOW
BLUE
BLACK
common
1st Stage (low capacity − 700 rpm)
2nd Stage (High capacity − 820 rpm)
B4
24V
Y1
Y2
RED
RED
YELLOW
BLUE
BLACK
B4
240V
24V
common
Y2
Y1
24V
0V
24V
24V
240V
240V
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