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©

2007 Lennox Industries Inc.

Corp. 0719−L5

14HPX

Service Literature

1.5 to 5 ton

Revised 06−2008

14HPX SERIES UNITS

The 14HPX is a residential split-system heat pump. The
series is designed for use with expansion valves (TXV) and
HFC−410A refrigerant.  All 14HPX units utilize scroll compres-
sors.

14HPX series 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
warranty. Refer to the Engineering Handbook for approved
system matchups.

This manual is divided into sections which discuss the
major components, refrigerant system, charging proce-
dure, maintenance and operation sequence.

Information contained in this manual is intended for use by
qualified service technicians only. All specifications are subject
to change.

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.

WARNING

Refrigerant can be harmful if it is inhaled. Refrigerant
must be used and recovered responsibly.

Failure to follow this warning may result in person-
al injury or death.

CAUTION

In order to avoid injury, take proper precaution when
lifting heavy objects.

Table of Contents

Specifications / Electrical Data

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I Unit Components

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II Refrigerant System

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III Charging

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IV Maintenance

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V Diagrams

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Summary of Contents for 14HPX

Page 1: ...vice technicians only All specifications are subject to change 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 techn...

Page 2: ...tor Amps 1 4 1 4 1 4 2 9 OPTIONAL ACCESSORIES must be ordered extra Compressor Crankcase Heater 93M04 S S S p Factory S Compressor Hard Start Kit 10J42 S S S S Compressor Low Ambient Cut Off 45F08 S S S S Compressor Sound Cover 69J03 S S S S Freezestat 3 8 in tubing 93G35 S S S S 5 8 in tubing 50A93 S S S S Hail Guards 92M89 S S 92M88 S 27W34 S Indoor Blower Off Delay Relay 58M81 S S S S Loss of C...

Page 3: ...Amps 2 9 2 9 2 9 OPTIONAL ACCESSORIES must be ordered extra Compressor Crankcase Heater Factory S S S Compressor Hard Start Kit 10J42 S S p 81J69 S Compressor Low Ambient Cut Off 45F08 S S S Compressor Sound Cover 69J03 S S S Freezestat 3 8 in tubing 93G35 S S S 5 8 in tubing 50A93 S S S Hail Guards 27W36 S S 94M94 S Indoor Blower Off Delay Relay 58M81 S S S Loss of Charge Kit 84M23 S S S 5 Low Am...

Page 4: ...ssor is energized by a contactor located in the control box See figure 2 Single pole contactors are used in 14HPX series units See wiring diagrams for specific unit K1 is energized through the CMC1 board by the in door thermostat terminal Y1 24V when thermostat de mand is present DANGER Electric Shock Hazard May cause injury or death Disconnect all remote electrical power supplies before opening u...

Page 5: ...ontrol Pressure Switch Settings High Pressure auto reset trip at 590 psig reset at 418 Low Pressure auto reset trip at 25 psig reset at 40 psig 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 pres sure switch opens and closes four times during a Y1 In put the control logic will reset the pressure switch...

Page 6: ...priate 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 board will lockout the unit Defrost board 24 volt power R must be cycled OFF or the TEST pins on board must be shorted between 1 to 2 sec onds to reset the board Defrost Temperature Termination Shunt Jumper Pins The defrost control selections ar...

Page 7: ...t cycle will be initiated after 34 minutes of heating mode compressor run time The con trol will attempt to self calibrate after this and all other de frost cycle s Calibration success depends on stable system tempera tures 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 comp...

Page 8: ...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 operat...

Page 9: ...g Valve ON W1 line ON Monitor coil temperature and time in defrost mode HOW DID DEFROST TERMINATE Coil temperature was above 35 F 2 C for 4 min of the 14 min de frost OR reached defrost termination temp DCB s 60L3901 and 46M8201 LO PS Termination Option selected Defrost terminated by pressure Defrosted for 14 min with out the coil temp going above 35 F 2 C for 4 min and coil did not reach terminat...

Page 10: ...as internal component failure Cycle 24 volt power to board If code does not clear replace control FAULT LOCKOUT CODES Each fault adds 1 strike to that code s counter 5 strikes per code LOCKOUT OFF SLOW Flash Low Pressure Fault 1 Restricted air flow over indoor or outdoor coil 2 Improper refrigerant charge in 1 Remove any blockages or restrictions from coils and or fans Check indoor and outdoor fan...

Page 11: ...tinues the gas is forced toward the center of the scroll and the gas pocket becomes compressed figure 12 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 11 The discharge pressure forcing down on the top scroll helps seal off the upper and lower edges tips of the scrolls figure 11 During a single orbit se...

Page 12: ...panel If replacing outdoor fan motor on the 14HPX 060 align motor shaft 1 4 from the hub For all other 14HPX model units motor shaft should be flush with hub See figure 13 Drip loops should be used in wir ing when servicing motor D Reversing Valve L1 and Solenoid A refrigerant reversing valve with electromechanical so lenoid is used to reverse refrigerant flow during unit op eration The reversing ...

Page 13: ...s taken out of the circuit I Drier A filter drier designed for all 14HPX model units is factory installed in the liquid line The filter drier is designed to re move moisture and foreign matter which can lead to com pressor failure Moisture and or Acid Check Because POE oils absorb moisture the dryness of the system must be verified any time the refrigerant sys tem is exposed to open air A compress...

Page 14: ...TION EXPANSION CHECK VALVE INDOOR UNIT OUTDOOR UNIT LIQUID LINE SERVICE PORT GAUGE MANIFOLD DISTRIBUTOR INDOOR COIL FIGURE 15 14HPX HEATING CYCLE SHOWING MANIFOLD GAUGE CONNECTIONS OUTDOOR COIL EXPANSION CHECK VALVE BIFLOW FILTER DRIER TO HFC 410A DRUM LOW PRESSURE HIGH PRESSURE COMPRESSOR REVERSING VALVE VAPOR LINE VALVE MUFFLER NOTE ARROWS INDICATE DIRECTION OF REFRIGERANT FLOW SERVICE PORT SUCT...

Page 15: ...serve as the primary leak seal NOTE Always keep valve stem caps clean To Access Schrader Port 1 Remove service port cap with an adjustable wrench 2 Connect gauge to the service port 3 When testing is completed replace service port cap Tighten finger tight then an additional 1 6 turn To Open Liquid or Vapor Line Service Valve 1 Remove stem cap with an adjustable wrench 2 Using service wrench and he...

Page 16: ...ll amount of HFC 410A 3 to 5 psig 20kPa to 34kPa then pressurize with nitrogen to 150 psig 4 Release nitrogen pressure from the system correct any leaks and recheck 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 WARNING Fire Expl...

Page 17: ...nd 7 Page 19 A blank space is provided on the unit rating plate to list the actual field charge IMPORTANT Mineral oils are not compatible with HFC 410A If oil must be added it must be a polyol ester oil A Check indoor air before charging Figure 18 IMPORTANT CHECK AIRFLOW BEFORE CHARGING NOTE Be sure that filters and indoor and outdoor coils are clean before testing Cooling mode indoor airflow chec...

Page 18: ...ance checks This is not a procedure for charging the unit Refer to Charging Checking Charge section Minor variations in these pressures may be expected due to differences in installations Significant differences could mean that the system is not properly charged or that a problem exists with some component in the system Table 5 Normal Operating Pressures Liquid 10 Vapor 5 PSIG 14HPX 018 14HPX 024 ...

Page 19: ...f necessary operate heating to reach that temperature range then set thermostat to cooling mode setpoint to 68ºF 20ºC When pressures have stabilized continue with step 6 Using heating mode When the outdoor ambient temperature is below 60 F 15 C Target subcooling values in table below are based on 65 75 F 18 24 C indoor return air temperature if necessary operate cooling to reach that temperature r...

Page 20: ...H 060 14 4 0 0 CBX27UH 030 11 6 2 4 CBX27UH 042 12 6 0 8 CBX27UH 060 12 5 0 0 CBX32M 030 11 6 1 6 CBX32M 048 12 6 0 7 CBX32M 048 060 12 5 0 0 CBX32M 036 11 6 2 4 CBX32MV 048 12 6 0 8 CBX32MV 048 060 12 5 0 0 CBX32MV 024 030 11 6 1 6 CH33 62D 12 6 0 10 CBX32MV 068 12 7 1 0 CBX32MV 036 11 6 2 4 CH33 50 60C 12 6 0 7 CH33 50 60C 12 5 0 0 C33 44C 11 6 2 3 CH33 60D 12 6 0 4 CH33 62D 12 5 0 0 CH33 36C 11...

Page 21: ...9 44 127 3 75 217 4 106 345 3 137 519 3 45 129 7 76 220 9 107 350 1 138 525 8 46 132 2 77 224 4 108 355 0 139 532 4 47 134 6 78 228 0 109 360 0 140 539 0 48 137 1 79 231 6 110 365 0 141 545 6 49 139 6 80 235 3 111 370 0 142 552 3 50 142 2 81 239 0 112 375 1 143 559 1 51 144 8 82 242 7 113 380 2 144 565 9 52 147 4 83 246 5 114 385 4 145 572 8 53 150 1 84 250 3 115 390 7 146 579 8 54 152 8 85 254 1 ...

Page 22: ...nit operating 6 Check amp draw on outdoor fan motor Unit nameplate__________Actual__________ 7 Inspect drain holes in coil compartment base and clean if necessary NOTE If insufficient heating or cooling occurs the unit should be gauged and refrigerant charge should be checked Indoor Coil 1 Clean coil if necessary 2 Check connecting lines joints and coil for evidence of oil leaks 3 Check condensate...

Page 23: ...Page 23 V WIRING DIAGRAM AND SEQUENCE OF OPERATION 14HPX UNIT DIAGRAM 5 1 2 3 4 6 ...

Page 24: ...nal thermostat wiring de energizes terminal O by heating mode selection de energizing the reversing valve L1 See steps 1 2 and 3 End of FIRST STAGE HEAT See steps 4 5 and 6 DEFROST MODE When a defrost cycle is initiated the control ener gizes the reversing valve solenoid and turns off the condenser fan The control will also put 24VAC on the W1 auxiliary heat line The unit will stay in this mode un...

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