Lennox XP14 SERIES, XP14−018, XP14−024, XP14−030, XP14−036 Unit Information

Page 1

©2007 Lennox Industries Inc.

Corp. 0721−L7

XP14

Service Literature

Revised 06−2008

XP14 SERIES UNITS

The XP14 is a high efficiency residential split−system heat
pump unit, which features a scroll compressor and
HFC−410A refrigerant. XP14 units are available in sizes
ranging from 1 1/2 through 5 tons. The series is designed
for use with an indoor unit with an expansion valve ap­proved for HFC−410A. 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.

IMPORTANT

Operating pressures of this HFC−410A unit are
higher than pressures in HCFC−22 units. Always
use service equipment rated for HFC−410A.

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).

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

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.

TABLE OF CONTENTS

Specifications / Electrical Page 2. . . . . . . . . . . . .

I Unit Information Page 3. . . . . . . . . . . . . . . . . . . .

II Unit Components Page 3. . . . . . . . . . . . . . . . . .

III Refrigerant System Page 13. . . . . . . . . . . . . . . .

IV Charging Page 15. . . . . . . . . . . . . . . . . . . . . . . . .

V Service and Recovery Page 20. . . . . . . . . . . . . .

VI Maintenance Page 21. . . . . . . . . . . . . . . . . . . . . .

VII Wiring Diagram Page 22. . . . . . . . . . . . . . . . . . .

Page 2

SPECIFICATIONS

General

Model No. XP14−018 XP14−024 XP14−030 XP14−036 XP14−042 XP14−048 XP14−060

Data

Nominal Tonnage 1.5

2 2.5 3 3.5 4 5

Connections

Liquid line o.d. − in. 3/8 3/8 3/8 3/8 3/8 3/8 3/8

(sweat)

Vapor line o.d. − in. 3/4

3/4 3/4 7/8 7/8 7/8 1-1/8

1

Refrigerant HFC−410A charge furnished 8 lbs.

4 oz.

8 lbs.

0 oz.

7 lbs.

2 oz.

9 lbs.

12 oz.

12 lbs.

7 oz.

12 lbs.

10 oz.

16 lbs.

0 oz.

Outdoor

Net face area

Outer coil 13.30 13.30 15.21 19.39 24.93 24.93 29.09

Coil sq. ft.

Inner coil 12.60

12.60 14.50 18.77 24.13 24.13 28.16

Tube diameter − in. 5/16 5/16 5/16 5/16 5/16 5/16 5/16

No. of rows 2 2 2 2 2 2 2

Fins per inch 22 22 22 22 22 22 22

Outdoor

Diameter − in. 18 18 18 26 26 26 26

Fan

No. of Blades 3

3 3 4 4 4 4

Motor hp 1/10 1/10 1/10 1/3 1/3 1/3 1/3

Cfm 2165 2165 2232 4090 4347 4347 4550

Rpm 1015 1015 1035 844 843 843 830

Watts 171 171 165 299 299 299 307

Shipping Data − lbs. 1 package 194 194 205 263 317 319 345

ELECTRICAL DATA

Line voltage data − 60 hz − 1ph 208/230V 208/230V 208/230V 208/230V 208/230V 208/230V 208/230V

2

Maximum overcurrent protection (amps) 20 30 30 30 40 50 60

3

Minimum circuit ampacity 11.9 17.5 17.0 19.4 24.2 29 34.8

Compressor

Rated Load Amps

8.97 13.46 13.1 14.1 17.94 21.79 26.41

p

Locked Rotor Amps

48 58 64 77 112 117 134

Power Factor

0.96 0.98 0.98 0.99 0.94 0.95 0.98

Outdoor

Full Load Amps

0.70 0.70 0.70 1.8 1.8 1.8 1.8

Fan Motor

Locked Rotor Amps

1.4

1.4 1.4 2.9 2.9 2.9 2.9

OPTIONAL ACCESSORIES − must be ordered extra

Compressor Crankcase Heater

93M04   

p

Factory    

Compressor Hard Start Kit

10J42      

p

81J69 
Compressor Low Ambient Cut−Off 45F08       
Freezestat

3/8 in. tubing 93G35       
5/8 in. tubing 50A93       

Indoor Blower Off Delay Relay 58M81       

4

Low Ambient Kit 54M89       
Mild Weather Kit 33M07       
Monitor Kit − Service Light 76F53       
Outdoor

Thermostat 56A87       

Thermostat Kit

Mounting Box 31461 

     

Refrigerant
Line Sets

L15−41−20
L15−41−30

L15−41−40
L15−41−50

  

e Sets

L15−65−30 L15−65−40

L15−65−50

  

Field Fabricate 

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

HACR type circuit breaker or fuse.

3

Refer to National or Canadian Electrical Code manual to determine wire, fuse and disconnect size requirements.

4

Crankcase Heater and Freezestat are recommended with Low Ambient Kit.

Page 3

I − UNIT INFORMATION

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.

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.

IMPORTANT

This unit must be matched with an indoor coil as
specified in Lennox’ Engineering Handbook.

II − UNIT COMPONENTS

Unit components are illustrated in figure 1.

XP14 UNIT COMPONENTS

FIGURE 1

OUTDOOR FAN

COMPRESSOR

HIGH PRESSURE

SWITCH

REVERSING

VALV E

FILTER

DRIER

CONTROL

BOX

EXPANSION

VALV E

VAPOR LINE

SERVICE

VALV E

LIQUID LINE

SERVICE

VALV E

A − Control Box (Figure 2)

XP14 units are not equipped with a 24V transformer. All 24
VAC controls are powered by the indoor unit. Refer to wir­ing diagram.

FIGURE 2

DUAL CAPACITOR

(C12)

COMPRESSOR

CONTACTOR

(K1)

SINGLE PHASE UNIT CONTROL BOX

GROUNDING

LUG

DEFROST

CONTROL

(A108)

Electrical openings are provided under the control box cov­er. Field thermostat wiring is made to a 24V terminal strip
located on the defrost control board located in the control
box. See figure 2.

24V THERMOSTAT TERMINAL STRIP

FIGURE 3

W1 C L R O Y1

*Y2

*not used

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 all XP14 series units. K1 is energized through the de­frost control by the indoor thermostat terminal Y1 (24V)
when thermostat demand is present.

DANGER

Electric Shock Hazard.
May cause injury or death.

Line voltage is present at all compo­nents 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.

Page 4

2 − Dual Capacitor C12

The compressor and fan in XP14 series units use permanent
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. See side of capacitor for
ratings.

3 − Defrost System (CMC1)

The demand defrost control measures differential temper­atures to detect when the system is performing poorly be­cause of ice build−up on the outdoor coil. The controller
self−calibrates" when the defrost system starts and after
each system defrost cycle. The defrost control compo­nents are shown in figure 4.

The control monitors ambient temperature, outdoor coil
temperature, and total run time to determine when a de­frost cycle is required. The coil temperature probe is de­signed with a spring clip to allow mounting to the outside
coil tubing. The location of the coil sensor is important for
proper defrost operation.

NOTE − The demand defrost control accurately measures
the performance of the system as frost accumulates on the
outdoor coil. This typically will translate into longer running
time between defrost cycles as more frost accumulates on
the outdoor coil before the board initiates defrost cycles.

Diagnostic LEDs

The state (Off, On, Flashing) of two LEDs on the defrost
board (DS1 [Red] and DS2 [Green]) indicate diagnostics
conditions that are described in table 2.

24V TERMINAL
STRIP
CONNECTIONS

DIAGNOSTIC
LEDS

PRESSURE

SWITCH CIRCUIT

CONNECTIONS

TEST PINS

NOTE − Component Locations Vary by Control Manufacturer.

Y2 not used on XP14

SENSOR

PLUG IN

(COIL & AM-

BIENT

SENSORS)

REVERSING

VALV E

DELAY

PINS

LOW
AMBIENT
THERMOSTAT
PINS

DEFROST
TERMINATION
PIN SETTINGS

FIGURE 4

Defrost Control Pressure Switch Connections

The unit’s automatic reset pressure switches (LO PS − S87
and HI PS − S4) are factory−wired into the defrost control on
the LO−PS and HI−PS terminals, respectively.

Low Pressure Switch (LO−PS)When the low pressure
switch trips, the defrost control will cycle off the compressor,
and the strike counter in the control will count one strike.
The low pressure switch is ignored under the following con­ditions:

during the defrost cycle and 90 seconds after the termina-

tion of defrost

when the average ambient sensor temperature is below

15° F (−9°C)
for 90 seconds following the start up of the compressor
during "test" mode
High Pressure Switch (HI−PS)When the high pressure

switch trips, the defrost control will cycle off the compressor,
and the strike counter in the control will count one strike.

Defrost Control Pressure Switch Settings

High Pressure (auto reset) − trip at 590 psig; reset at 418.
Low Pressure (auto reset) − trip at 25 psig; reset at 55.

5−Strike Lockout Feature

The internal control logic of the control counts the pressure
switch trips only while the Y1 (Input) line is active. If a pres­sure switch opens and closes four times during a Y1 (Input),
the control logic will reset the pressure switch trip counter to
zero at the end of the Y1 (Input). If the pressure switch
opens for a fifth time during the current Y1 (Input), the con­trol will enter a lockout condition.

The 5−strike pressure switch lockout condition can be reset
by cycling OFF the 24−volt power to the control board or by
shorting the TEST pins between 1 and 2 seconds. All timer
functions (run times) will also be reset.

If a pressure switch opens while the Y1 Out line is engaged,
a 5−minute short cycle will occur after the switch closes.

Defrost System Sensors

Sensors connect to the defrost control through a field-re­placeable harness assembly that plugs into the board.
Through the sensors, the control detects outdoor ambient
and coil temperature fault conditions. As the detected tem­perature changes, the resistance across the sensor
changes. Figure 5 shows how the resistance varies as the
temperature changes for both type of sensors. Sensor re­sistance values can be checked by ohming across pins
shown in table 1.

TABLE 1

Sensor

Temperature
Range °F (°C)

Resistance values
range (ohms)

Pins/Wire
Color

Outdoor
(Ambient)

−35 (−37) to 120
(48)

280,000 to 3750 3 & 4

(Black)

Coil −35 (−37) to 120

(48)

280,000 to 3750 5 & 6

(Brown)

Discharge (if
applicable)

24 (−4) to 350
(176)

41,000 to 103 1 & 2

(Yellow)

Note: Sensor resistance decreases as sensed temperature increases
(see figure5).

NOTE − When checking the ohms across a sensor, be
aware that a sensor showing a resistance value that is not
within the range shown in table 1, may be performing as de­signed. However, if a shorted or open circuit is detected,
then the sensor may be faulty and the sensor harness will
needs to be replaced.

Page 5

Coil SensorThe coil temperature sensor (shown in fig­ure 6) considers outdoor temperatures below −35°F (−37°C)
or above 120°F (48°C) as a fault. If the coil temperature
sensor is detected as being open, shorted or out of the tem­perature range of the sensor, the defrost control will not per­form demand or time/temperature defrost operation and
will display the appropriate fault code. Heating and cooling
operation will be allowed in this fault condition.

Ambient and Coil Sensor

RESISTANCE (OHMS)

TEMPERATURE (ºF)

5750

7450

9275

11775

15425

19975

26200

34375

46275

62700

100

90

80

70

60

50

40

30

20

10

0

10000 30000 50000 70000 90000

85300

FIGURE 5

COIL SENSOR

−
Clip coil temperature sensor from the de­frost control on the bend shown − 6th
bend up. Apply grease between bend
and sensor.

AMBIENT
SENSOR

FIGURE 6

Ambient SensorThe ambient sensor (shown in figure 6)

considers outdoor temperatures below −35°F (−37°C) or
above 120°F (48°C) as a fault. If the ambient sensor is de­tected as being open, shorted or out of the temperature
range of the sensor, the control will not perform demand de­frost operation. The control will revert to time/temperature
defrost operation and will display the appropriate fault
code. Heating and cooling operation will be allowed in this
fault condition.

NOTE − Within a single room thermostat demand, if
5−strikes occur, the control will lockout the unit. Defrost con­trol 24 volt power R" must be cycled OFF" or the TEST"
pins on the control must be shorted between 1 to 2 seconds
to reset the control.

Defrost Temperature Termination Shunt (Jumper)
PinsThe defrost control selections are: 50, 70, 90, and

100°F (10, 21, 32 and 38°C). The shunt termination pin is
factory set at 50°F (10°C). If the temperature shunt is not
installed, the default termination temperature is 90°F
(32°C).

Delay Mode

The defrost control has a field−selectable function to reduce
occasional sounds that may occur while the unit is cycling in
and out of the defrost mode. When a jumper is installed on
the DELAY pins, the compressor will be cycled off for 30
seconds going in and out of the defrost mode. Units are
shipped with jumper installed on DELAY pins.

Page 6

NOTE − The 30 second off cycle is NOT functional when
jumpering the TEST pins.

Operational Description

The defrost control has three basic operational modes:
normal, calibration, and defrost.

Normal ModeThe demand defrost control monitors the
O line, to determine the system operating mode (heat/cool),
outdoor ambient temperature, coil temperature (outdoor
coil) and compressor run time to determine when a defrost
cycle is required.

Calibration ModeThe control is considered uncali­brated when power is applied to the control, after cool mode
operation, or if the coil temperature exceeds the termina­tion temperature when it is in heat mode.

Calibration of the control occurs after a defrost cycle to en­sure that there is no ice on the coil. During calibration, the
temperature of both the coil and the ambient sensor are
measured to establish the temperature differential which is
required to allow a defrost cycle. See figure 8 for calibration
mode sequence.

Defrost ModeThe following paragraphs provide a de­tailed description of the defrost system operation.

Detailed Defrost System Operation

Defrost CyclesThe demand defrost control initiates a

defrost cycle based on either frost detection or time.
Frost DetectionIf the compressor runs longer than 34

minutes and the actual difference between the clear
coil and frosted coil temperatures exceeds the maxi­mum difference allowed by the control, a defrost cycle
will be initiated.

TimeIf 6 hours of heating mode compressor run time has

elapsed since the last defrost cycle while the coil tem­perature remains below 35°F (2°C), the demand de­frost control will initiate a defrost cycle.

ActuationWhen the reversing valve is de−energized, the
Y1 circuit is energized, and the coil temperature is below
35°F (2°C), the control logs the compressor run time. If the
control is not calibrated, a defrost cycle will be initiated after
34 minutes of heating mode compressor run time. The con­trol will attempt to self−calibrate after this (and all other) de­frost cycle(s).

Calibration success depends on stable system tempera­tures during the 20−minute calibration period. If the control
fails to calibrate, another defrost cycle will be initiated after
45 minutes (90 minutes −1 to −4 boards) of heating mode
compressor run time. Once the defrost control is calibrated,
it initiates a demand defrost cycle when the difference be­tween the clear coil and frosted coil temperatures exceeds
the maximum difference allowed by the control OR after 6
hours of heating mode compressor run time has been
logged since the last defrost cycle.

NOTE − If ambient or coil fault is detected, the control will not
execute the TEST" mode.

TerminationThe defrost cycle ends when the coil tem­perature exceeds the termination temperature or after 14
minutes of defrost operation. If the defrost is terminated by
the 14−minute timer, another defrost cycle will be initiated
after 34 minutes of run time.

Test ModeWhen Y1 is energized and 24V power is being
applied to the control, a test cycle can be initiated by placing
the termination temperature jumper across the Test" pins
for 2 to 5 seconds. If the jumper remains across the Test"
pins longer than 5 seconds, the control will ignore the test
pins and revert to normal operation. The jumper will initiate
one cycle per test.

Enter the TEST" mode by placing a shunt (jumper) across
the TEST" pins on the control after power−up. (The TEST"
pins are ignored and the test function is locked out if the
shunt is applied on the TEST" pins before power−up). Con­trol timings are reduced, the low−pressure switch is ignored
and the control will clear any active lockout condition.

Each test pin shorting will result in one test event. For
each TEST" the shunt (jumper) must be removed for at
least 1 second and reapplied. Refer Defrost Control Pin Op­erationto flow chart (figure 7) for TEST" operation.

Note: The Y1 input must be active (ON) and the O" room
thermostat terminal into board must be inactive.

Defrost Control Diagnostics

See table 2 to determine defrost control operational condi­tions and to diagnose cause and solution to problems.

Page 7

If in COOLING Mode If in HEATING Mode If in DEFROST Mode

Short test pins for longer

than 1 second but less than

2 seconds

Short test pins for more than 2 seconds

Y1 Active (0" line inactive)

Test pin short REMAINS in place for more than 5 seconds Test pins short REMOVED before a

maximum of 5 seconds

Clear any short cycle lockout

and 5 strike fault lockout

function, if applicable. No

other functions will be
executed and unit will

continue in the mode it was

operating.

No further test mode

operation will be

executed until the test

short is removed and

reapplied.

The control will check for ambient

and coil faults (open or shorted).

If a fault exists

, the unit will

remain in Heat Mode and no

further test mode operation will

be executed until the test short is

removed and re applied. If
no fault exists

and ambient

temperature is below 35ºF, the

unit will go into Defrost mode.

The unit will terminate

defrost and enter Heat

Mode uncalibrated with

defrost timer set for 34
minute test. No further

test mode operation will

be executed until the test

short is removed and

reapplied.

Clear any short cycle lockout and 5 strike

fault lockout function, if applicable.

The unit will return to Heat mode uncalibrated with defrost

timer set for 34 minutes. No further test mode operation will

be executed until the test short is removed and re applied.

The unit will remain in Defrost mode

until termination on time or temperature

FIGURE 7

Defrost Control Pin Operation