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Fujitsu FO20R Series Installation Instructions Manual

Variable speed r-410a heat pump outdoor units
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WARNING:
RECOGNIZE THIS SYMBOL
AS AN INDICATION OF
IMPORTANT SAFETY
INFORMATION
WARNING
THESE INSTRUCTIONS
ARE INTENDED AS AN AID
TO QUALIFIED, LICENSED
SERVICE PERSONNEL FOR
PROPER INSTALLATION,
ADJUSTMENT, AND
OPERATION OF THIS UNIT.
READ THESE INSTRUCTIONS
THOROUGHLY BEFORE
ATTEMPTING INSTALLATION
OR OPERATION. FAILURE
TO FOLLOW THESE
INSTRUCTIONS MAY
RESULT IN IMPROPER
INSTALLATION,
ADJUSTMENT, SERVICE,
OR MAINTENANCE
POSSIBLY RESULTING IN
FIRE, ELECTRICAL SHOCK,
PROPERTY DAMAGE,
PERSONAL INJURY, OR
DEATH.
Do not destroy this manual.
Please read carefully and
keep in a safe place for future
reference by a serviceman.
[ ] indicates metric conversions.
Printed in USA
92-105074-16-01 ( / )
VARIABLE SPEED R-410A
HEAT PUMP OUTDOOR UNITS
INSTALLATION INSTRUCTIONS
FO20R (20 SEER) EQUIPPED WITH
DIGITAL COMMUNICATIONS

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  Summary of Contents for Fujitsu FO20R Series

  • Page 1 VARIABLE SPEED R-410A WARNING: HEAT PUMP OUTDOOR UNITS RECOGNIZE THIS SYMBOL AS AN INDICATION OF IMPORTANT SAFETY INFORMATION INSTALLATION INSTRUCTIONS WARNING THESE INSTRUCTIONS FO20R (20 SEER) EQUIPPED WITH ARE INTENDED AS AN AID TO QUALIFIED, LICENSED DIGITAL COMMUNICATIONS SERVICE PERSONNEL FOR PROPER INSTALLATION, ADJUSTMENT, AND OPERATION OF THIS UNIT.
  • Page 2: Table Of Contents

    CONTENTS 1.0 IMPORTANT SAFETY INFORMATION............3 6.0 NORMAL SEQUENCE OF OPERATION..........30-32 2.0 GENERAL INFORMATION..............4-5 2.5 Importance of Proper Indoor/Outdoor Match-Ups......5 2.6 Checking Product Received..............5 6.7 Demand Defrost.................31 ...32 3.0 UNIT SPECIFICATIONS................5-6 7.0 COMPONENTS AND CONTROLS............33-39 7.1 Accumulator..................33 3.2 Electrical and Physical Data ..............6 7.2 Choke/Inductor .................33 4.0 INSTALLATION...................7-25 7.3 Coil Temperature Thermistor.............33...
  • Page 3: Important Safety Information

    1.0 IMPORTANT SAFETY INFORMATION WARNINGS: CAUTIONS: • These instructions are intended as an aid to • R-410A systems operate at approximately 60% higher qualified, licensed service personnel for proper pressures (1.6 times) than R-22 systems. Do not use installation, adjustment, and operation of this unit. R-22 service equipment or components on R-410A Read these instructions thoroughly before attempting equipment.
  • Page 4: General Information

    2.0 GENERAL INFORMATION 2.3 Importance of WARNING: Quality Installation Improper installation, or installation not made in accordance with these instructions, can result A quality installation is critical to assure safety, in unsatisfactory operation and/or dangerous reliability, comfort, and customer satisfaction. Strict conditions and can cause the related warranty adherence to applicable codes, the information in not to apply.
  • Page 5: Importance Of Proper Indoor/Outdoor Match-Ups

    V – VARIABLE SPEED PRODUCT CATEGORY R – HEAT PUMP SEER AVAILABLE MODELS 20 - 20 SEER FO2420RVJCAB CAPACITY 24 – 24,000 BTU FO3620RVJCAB 36 – 36,000 BTU 48 – 48,000 BTU FO4820RVJCAB 60 – 60,000 BTU FO6020RVJCAB BRAND FO – FUJITSU...
  • Page 6: Unit Specifications

    3.0 UNIT SPECIFICATIONS 3.2 Electrical and Physical Data 2420 3620 4820 6020 2420 3620 4820 6020 ALLOW 60” [1524mm] OF CLEARANCE “W” “L” “H” SERVICE PANELS/ INLET CONNECTIONS / HIGH & LOW VOLTAGE ACCESS ALLOW 24” [ 610 mm] OF CLEARANCE AIR INLET LOUVERS ALLOW 6”...
  • Page 7: Installation

    4.0 INSTALLATION 4.1 Tools and Refrigerant 4.1.1 Tools Required for Pressure: The pressure of R-410A is approximately 60% (1.6 times) greater than Installing and Servicing R-22. Recovery and recycle equipment, pumps, R-410A Models hoses, and the like must have design pressure ratings appropriate for R-410A.
  • Page 8 4.0 INSTALLATION 4.2 Choosing a Location 4.2.1 Allowable Clearances 4.2.2 Operational Issues Related to Unit Location 12" to side intake louvers 24" to service access panels IMPORTANT: 60" vertical for fan discharge Locate the unit in a If space limitations exist, the following clearances manner that will not prevent, impair, or compromise will have minimal impact to capacity and efficiency the performance of other equipment installed...
  • Page 9 4.0 INSTALLATION 4.2 Choosing a Location (cont.) 4.2.3 Corrosive Environment 4.3 Unit Mounting The metal parts of this unit may be subject to 4.3.1 Unit Mounting Methods rust or deterioration if exposed to a corrosive environment. This oxidation could shorten the The outdoor heat pump unit may be mounted in equipment’s useful life.
  • Page 10 4.0 INSTALLATION 4.3.3 Elevating Unit NOTICE: Do not block drain openings on bottom of unit. WARNING: Secure an elevated unit and • If unit must be elevated because of anticipated its elevating stand in order to prevent tipping. Failure to snowfall, secure unit and elevating stand such that do so may result in severe personal injury or death.
  • Page 11 4.0 INSTALLATION 4.4 Refrigerant Line Set Selection 4.4.1 Replacing Existing 4.4.2.2 Refrigerant Migration Dur- ing Off Cycle Systems Long line set applications can require a consider- To prevent failure of a new unit, the existing line set able amount of additional refrigerant. This addition- must be correctly sized for the new unit and must al refrigerant needs to be managed throughout the be cleaned or replaced.
  • Page 12 4.0 INSTALLATION 4.4.2.5 Oil Level Adjustment for ((66 oz. + 212 oz.) × .022) – (.10 × 40 oz.) = 2 oz. Long Line Set Applications 4.4.2.6 Capacity Losses Long line lengths can result in a reduction in capac- Additional oil will need to be added if refrigerant is ity due to vapor line pressure drop and heat gain or added during installation.
  • Page 13 4.0 INSTALLATION 4.4.4 Liquid Line Selection • Add all of the equivalent lengths associated with The purpose of the liquid line is to transport warm sub-cooled liquid refrigerant between the outdoor unit length. This will equal your total equivalent line to the indoor unit in the cooling mode.
  • Page 14 4.0 INSTALLATION **See Note 4...
  • Page 15 4.0 INSTALLATION [5 Ton] ** See Note 4...
  • Page 16 4.0 INSTALLATION 4.5 Line Set Installation • If tubing is to be run underground, it must be run in in the heating mode will result in noise inside the a sealed watertight chase. structure. • Use care in routing tubing and do not kink or twist. •...
  • Page 17 4.0 INSTALLATION 4.5 Line Set Installation (cont.) 4.5.2 Relative Location of Indoor and Outdoor Units 4.5.2.1 Outdoor Unit Level or Near Level to Indoor Coil Line Set REFERENCE TABLE 2 FOR MAXIMUM LENGTH LIMITATIONS IDEALLY, LINE SET SLOPES AWAY FROM OUTDOOR UNIT. VERIFY SUB-COOLING PRIOR TO EXPANSION DEVICE, INSULATED LIQUID LINE IN UNCONDITIONED SPACE FOR...
  • Page 18 4.0 INSTALLATION 4.5.2.2 Outdoor Unit Below Indoor Coil (Long Line Set Applications) INSULATED VAPOR LINE FULL LENGTH INVERTED TRAP VERIFY LIQUID SUBCOOLING EVEN WITH TOP PRIOR TO EXPANSION DEVICE OF THE COIL IN THE COOLING MODE. INSULATE LIQUID LINE IN UNCONDITIONED SPACE FOR LONG REFERENCE TABLE 2 FOR LINE APPLICATIONS...
  • Page 19 4.0 INSTALLATION 4.5.2.3 Outdoor Unit Above Indoor Coil Figure 5 For applications with the outdoor unit above the • Insulated vapor line full length. indoor coil the following is required: • Verify at least 5°F [2.8ºC] of liquid subcooling at •...
  • Page 20 4.0 INSTALLATION 4.5.3 Tubing Connections Indoor coils have only a holding charge of dry nitrogen. Keep all tube ends sealed until connections are to be made. • Use type “L” copper refrigeration tubing. Braze the connections with the following alloys: –...
  • Page 21 4.0 INSTALLATION 4.6 Initial Leak Testing Indoor coils have only a holding charge of dry nitrogen. Keep all tube ends sealed until connections are to be made. WARNING: Do not use oxygen to purge lines or pressurize system for leak test. Oxygen reacts violently with oil, which can cause ST-A1226-06-00 an explosion resulting in severe personal injury or...
  • Page 22 4.0 INSTALLATION 4.9.1 Digital Communications The 20 SEER heat pumps are specifically designed to be matched with and communicating air-handler or gas furnace and the Digital Control Center. While they are also designed to be controlled by a conventional 24VAC 2-stage thermostat, many features and benefits are lost.
  • Page 23: Digital

    4.0 INSTALLATION 4.9 Control Wiring (cont.) IMPORTANT: 4.9.4 Conventional 24VAC The communicating Thermostat Control Wiring control system requires continuous 18 AWG thermostat wire. Do not use phone cord to Connections connect indoor and outdoor units. This will damage the controls. The 20 SEER heat pumps allow the installer to use conventional 24 VAC control wiring and a The communicating control system requires four...
  • Page 24 4.0 INSTALLATION 4.9 Control Wiring (cont.) 4.10 Power Wiring TYPICAL SINGLE-STAGE THERMOSTAT: It is important that proper electrical power is HEAT PUMP WITH AIR-HANDLER available at the heat pump power terminal block. The acceptable operating voltage range is shown below. VOLTAGE RANGES Nameplate Operating Voltage Range at...
  • Page 25: System Start-Up And Refrigerant Charging

    4.0 INSTALLATION 4.11 Grounding WARNING: The unit must be permanently grounded. Failure to do so can cause electrical shock resulting in severe personal injury or death. A ground lug is provided near the line-voltage power entrance for a ground wire. Ground Lug ST-A1241-01-X0 5.0 SYSTEM START-UP AND REFRIGERANT CHARGING...
  • Page 26 5.0 SYSTEM START-UP AND REFRIGERANT CHARGING 5.4 Initial System 9. To end Charge Mode, touch the "UP" arrow repeatedly until "OFF" is displayed on the Start-Up screen and then touch "Stop Test". Then touch the left arrow on the screen to return to the main screen.
  • Page 27 5.0 SYSTEM START-UP AND REFRIGERANT CHARGING 5.7 Indoor Air-Flow will display the indoor CFM in the Service Menu of the control. The approximate CFM is also Verification displayed in 100 CFM increments by a flashing LED on the air-handler or furnace control board while the blower is operating (one flash per 100 Correct indoor air-flow and proper supply air CFM) for installations where a conventional 24VAC...
  • Page 28 5.0 SYSTEM START-UP AND REFRIGERANT CHARGING 5.8.1 Measurement Device and adjust as necessary. CHARGING BY LIQUID SUBCOOLING PER THE SYSTEM CHARGING Set-Up CHART MUST BE USED FOR FINAL CHARGE ADJUSTMENT. 1. With an R-410A gauge set, attach the high- pressure hose to the access fitting on the liquid line (small) service valve at the OD unit.
  • Page 29 5.0 SYSTEM START-UP AND REFRIGERANT CHARGING NOTICE: NOTICE: The refrigerant pressures Systems should not be charged provided are for preliminary charge check ONLY. below 40°F [4.4°C] outdoor temperature. These pressure values are typical, but may vary NOTICE: If the indoor temperature is due to application.
  • Page 30: Normal Sequence Of Operation

    6.0 NORMAL SEQUENCE OF OPERATION The following sections provide details on how in an attempt to meet the building load until the the 20 SEER heat pump systems are designed maximum compressor speed is reached. Since the to operate under normal conditions. Under noise level of the compressor increases as speed abnormal conditions, Active Compressor and increases, the maximum allowable compressor...
  • Page 31: Demand Defrost

    6.0 NORMAL SEQUENCE OF OPERATION the compressor starts, the VSODC will direct the 6.6 Dual Fuel Applications variable speed ECM outdoor motor to operate at – Heating Mode the appropriate speed to deliver the necessary outdoor air-flow for that capacity percentage. Upon a call for heating, the Digital Control If the building load should exceed the heat pump Center accesses the indoor air-flow parameters...
  • Page 32 6.0 NORMAL SEQUENCE OF OPERATION 6.8 Sequence The indoor air-handler or gas furnace is directed to supply supplemental heat of Operation for to prevent cold air from being discharged Conventional 24VAC from the supply registers during the defrost cycle. Thermostat Controls The compressor speed is ramped to the pre-determined defrost speed for the When the 20 SEER heat pump system is controlled...
  • Page 33: Components And Controls

    7.0 COMPONENTS & CONTROLS 7.1 Accumulator 7.4 Compressor 20 SEER heat pumps are equipped with a All 20 SEER heat pumps are equipped with an Copeland variable speed scroll compressor accumulator for the purpose of managing possible with a brushless Permanent Magnet motor. The refrigerant flood back issues that may occur at compressor is designed to work in conjunction abnormal environmental conditions.
  • Page 34 7.0 COMPONENTS & CONTROLS 7.6 Variable Speed Outdoor Control (VSODC) 7.6.1 Board Features and 4. Outdoor PSC Fan relay connections 5. Outdoor ambient thermistor connection Connections 6. Coil sensor (EVAPIN) and suction thermistor (OST) connections 20 SEER heat pumps are equipped with a Variable Speed Outdoor Control (VSODC) that interfaces 7.
  • Page 35: Memory Card

    7.0 COMPONENTS & CONTROLS 7.6 Variable Speed Outdoor Control (VSODC) (cont.) 7.6.2 TEST and SW2 Buttons 7.6.3 Memory Card TEST and SW2 buttons are used to enter the • The memory card stores all unit information. following menus and modes: •...
  • Page 36 7.0 COMPONENTS & CONTROLS 7.6 Variable Speed Outdoor Control (VSODC) (cont.) 7.6.7 Menu Structure IMPORTANT: This mode should be manually exited. If this menu is not exited manually The VSODC is equipped with a dual 7-segment the VSODC will wait 24 hours before returning to LED display and two push buttons (SW2 and normal operation.
  • Page 37 7.0 COMPONENTS & CONTROLS 7.7 Electronic Expansion Valve 20 SEER heat pumps are equipped with electronic serviceability. An internal check valve is provided expansion valves (EXV). The advantage an EXV is that assures unrestricted flow in the reverse its ability to accurately control refrigerant flow over direction when the system is operating in the a much wider capacity range than a conventional cooling mode.
  • Page 38 7.0 COMPONENTS & CONTROLS 7.9 High Pressure 7.12 Outdoor Ambient Control (HPC) Temperature Sensor Sensing of the compressor discharge pressure is The outdoor ambient temperature is sensed by a accomplished by a conventional automatic reset thermistor located directly underneath the control pressure control that is brazed into the compressor box where it is shielded from direct sunlight.
  • Page 39 7.0 COMPONENTS & CONTROLS as the operating conditions remain within the safe operating range of the compressor and inverter. 1. High voltage input (L1 – Black; L2 – Yellow) 2. Ground connection 3. Choke Connection 4. High Pressure control connection (HPS) – with automatic reset 5.
  • Page 40: Active System Protection Features

    8.0 ACTIVE SYSTEM PROTECTION FEATURES The controls found in the 20 SEER heat pumps the Inverter will gradually increase the compressor are designed to prevent the system from operating RPM until the compressor returns to normal in under conditions that could be harmful to the speed based on the capacity demand.
  • Page 41 8.0 ACTIVE SYSTEM PROTECTION FEATURES If there are 3 low pressure faults in the same call 8.8 Overcurrent and for cooling or during 120 minutes of continuous Current Imbalance heating operation, the VSODC will lock the compressor out and flash a 21L fault code and the Digital Control Center will display a Low If the compressor current exceeds an acceptable Refrigerant Pressure Lockout fault on the screen.
  • Page 42 8.0 ACTIVE SYSTEM PROTECTION FEATURES 8.13 Sensor Failure Default Operation If the controls sense an externally connected sensor displayed on the Digital Control Center and Variable has failed, the system will enter a fail safe operating Speed Outdoor Control identifying which sensor has mode and will continue to condition the space until failed.
  • Page 43: Diagnostics And Troubleshooting

    9.0 DIAGNOSTICS & TROUBLESHOOTING Advanced operating status and diagnostic will operate. information is available through the Variable Speed 3) The display will change to a steady “c,” “C,” Outdoor Control dual 7-segment display and the “h,” or “H” to show the current demand for Digital Control Center that greatly enhances the unit operation.
  • Page 44 9.0 DIAGNOSTICS & TROUBLESHOOTING 9.4 Status and Diagnostic Codes Descriptions of the VSODC status codes are provided below. NOTE: Codes must be read from correct side to avoid an error in reading codes. Dual 7-Segment Status/Possible Cause – LEDs Display Status Code Description Troubleshooting Information Code...
  • Page 45 9.0 DIAGNOSTICS & TROUBLESHOOTING 9.4 Status and Diagnostic Codes (cont.) The error codes below will be displayed at the Digital Control Center under Service window / Current Faults or in the Fault History and will be time and date stamped. VSODC fault code will be displayed on the VSODC (Variable Speed Outdoor Control).
  • Page 46 9.0 DIAGNOSTICS & TROUBLESHOOTING 9.4 Status and Diagnostic Codes (cont.) The error codes below will be displayed at the Digital Control Center under Service window / Current Faults or in the Fault History and will be time and date stamped. VSODC fault code will be displayed on the VSODC (Variable Speed Outdoor Control).
  • Page 47 9.0 DIAGNOSTICS & TROUBLESHOOTING 9.4 Status and Diagnostic Codes (cont.) The error codes below will be displayed at the Digital Control Center under Service window / Current Faults or in the Fault History and will be time and date stamped. VSODC fault code will be displayed on the VSODC (Variable Speed Outdoor Control).
  • Page 48 9.0 DIAGNOSTICS & TROUBLESHOOTING 9.4 Status and Diagnostic Codes (cont.) The error codes below will be displayed at the Digital Control Center under Service window / Current Faults or in the Fault History and will be time and date stamped. VSODC fault code will be displayed on the VSODC (Variable Speed Outdoor Control).
  • Page 49 9.0 DIAGNOSTICS & TROUBLESHOOTING 9.4 Status and Diagnostic Codes (cont.) The error codes below will be displayed at the Digital Control Center under Service window / Current Faults or in the Fault History and will be time and date stamped. VSODC fault code will be displayed on the VSODC (Variable Speed Outdoor Control).
  • Page 50 9.0 DIAGNOSTICS & TROUBLESHOOTING 9.4 Status and Diagnostic Codes (cont.) The error codes below will be displayed at the Digital Control Center under Service window / Current Faults or in the Fault History and will be time and date stamped. VSODC fault code will be displayed on the VSODC (Variable Speed Outdoor Control).
  • Page 51 9.0 DIAGNOSTICS & TROUBLESHOOTING 9.4 Status and Diagnostic Codes (cont.) The error codes below will be displayed at the Digital Control Center under Service window / Current Faults or in the Fault History and will be time and date stamped. VSODC fault code will be displayed on the VSODC (Variable Speed Outdoor Control).
  • Page 52 9.0 DIAGNOSTICS & TROUBLESHOOTING 9.5 Active Protection Fault Details L8 – Compressor Model Unknown – A900_O IMPORTANT: This mode of active Inverter Identity Fault protection must be manually reset If the inverter compressor model is not set, the inverter will keep the compressor from operation. The VSODC will lock out the compressor to keep it from operating and flash an ”L”...
  • Page 53 9.0 DIAGNOSTICS & TROUBLESHOOTING 9.5 Active Protection Fault Details (cont.) L15 – PIM Over-temp – T908_O Inverter Fault IMPORTANT: This mode of active If the inverter detects an over temperature condition in the Power Module circuit the inverter protection must be manually reset. will automatically shut the compressor off and keep it from operation.
  • Page 54 9.0 DIAGNOSTICS & TROUBLESHOOTING 9.5 Active Protection Fault Details (cont.) automatically shut the compressor off and keep it from operation. If this fault occurs 3 times during one call for operation the VSODC will lock out the compressor to keep it from continuing to operate and flash an ”L”...
  • Page 55 9.0 DIAGNOSTICS & TROUBLESHOOTING 9.5 Active Protection Fault Details (cont.) IMPORTANT: and flash an ”L” on the dual 7-segment LEDs This mode of active followed by a 16. protection must be manually reset. IMPORTANT: This mode of active protection must be automatic reset once the discharge line thermistor fault is corrected.
  • Page 56 9.0 DIAGNOSTICS & TROUBLESHOOTING 9.5 Active Protection Fault Details (cont.) 16 – HP Sensor Not Configured – T926_O Active Protection – Code If the inverter is not configured or does not hold the configuration for the high pressure switch in the 21L –...
  • Page 57 9.0 DIAGNOSTICS & TROUBLESHOOTING 9.5 Active Protection Fault Details (cont.) increases to 187VAC. At this time the VSODC IMPORTANT: It is common during will restart the compressor. While the compressor startup and shutdown for the compressor to is off the VSODC will display a 27 on the dual venture outside the designed operating envelope.
  • Page 58 9.0 DIAGNOSTICS & TROUBLESHOOTING 9.5 Active Protection Fault Details (cont.) 83 – Evaporator Temperature Thermistor Failure D1 – Memory Card Configuration Data Write – T953_O Failure – A951_O If the VSODC identifies an issue with the If the VSODC identifies issue(s) writing the model Evaporator Temperature Thermistor (EVAPIN) data from the memory card, the VSODC will sensor the VSODC will flash an 83 on the dual...
  • Page 59 9.0 DIAGNOSTICS & TROUBLESHOOTING 9.6 Electrical Checks Flowchart THERMOSTAT CALL FOR COOLING OPERATION, NO COOLING OPERATION...
  • Page 60 9.0 DIAGNOSTICS & TROUBLESHOOTING 9.7 Cooling Mechanical Checks Flowchart...
  • Page 61 9.0 DIAGNOSTICS & TROUBLESHOOTING 9.8 Heating Mechanical Checks Flowchart...
  • Page 62 9.0 DIAGNOSTICS & TROUBLESHOOTING 9.9 Defrost Mechanical Checks Flowchart Defrost System Incomplete Excessive Defrost Defrost Defrost Time Reversing Valve Sensor in Wrong Sensor in Wrong Stuck Location Location Welded Reversing Valve Wrong Defrost Low System Relay on Control Board Timer Setting Charge Loose Defrost Wind Affecting...
  • Page 63 9.0 DIAGNOSTICS & TROUBLESHOOTING 9.10 Checking Transducers & Temperature Sensors TRANSDUCERS: Starting with some arbitrary numbers completion of the formula should look like this: Checking transducers for accuracy can be tricky at best. A technician will be required to do some SUCTION LINE TRANSDUCER: voltage reading and algebraic math to validate the VDC out = 2.4...
  • Page 64 9.0 DIAGNOSTICS & TROUBLESHOOTING 9.10 Checking Transducers & Temperature Sensors (cont.) TEMPERATURE SENSORS: All the temperature sensors/thermistors used in Apply resistance measurements to the chart found the equipment use the same scale of 10,000 Ohms below and compare to the control. at 77ºF (25ºC).
  • Page 65 9.0 DIAGNOSTICS & TROUBLESHOOTING 9.11 General Troubleshooting Guide WARNING: Disconnect all power to unit before servicing. Contactor may break only one side. Failure to shut off power can cause electrical shock resulting in personal injury or death. SYMPTOM POSSIBLE CAUSE REMEDY Unit will not run •...
  • Page 66 9.0 DIAGNOSTICS & TROUBLESHOOTING 9.12 Service Analyzer Charts High superheat Low charge Check system charge. (greater than 15°F [-8.3°C] at coil) Verify suction thermistor operation (10k thermistor) Replace thermistor. Verify pressure transducer operation input and Replace thermistor and/or harness and/or control output voltage board.
  • Page 67 9.0 DIAGNOSTICS & TROUBLESHOOTING 9.12 Service Analyzer Charts (cont.) Short cycling of Low charge Check system charge. compressor (cont.) Dirty coil Duct too small or restricted Faulty internal overload Replace compressor. Voltage present on Communication failure from VSODC to inverter. Check communication harness connectors and wire load side of inverter continuity.
  • Page 68 9.0 DIAGNOSTICS & TROUBLESHOOTING 9.12 Service Analyzer Charts (cont.) Moisture Poor evacuation on installation or during service High head pressure Noncondensibles air Unusual head and Wrong refrigerant or mixed refrigerants suction pressure readings Foreign matter – Copper tubing cuttings In each case, the cure is the same. Recover refrigerant, flush system.
  • Page 69 9.0 DIAGNOSTICS & TROUBLESHOOTING 9.12 Service Analyzer Charts (cont.) POSSIBLE CAUSE Bad pressure reading Check transducer wiring. Suction thermistor in wrong location Relocate thermistor. Poor system control using an EXV Bad suction thermistor Replace thermistor. Improper superheat setting (less than 5°F [-2.8°C]) Adjust EXV SH setpoint dipswitches and validate valve operation.
  • Page 70 9.0 DIAGNOSTICS & TROUBLESHOOTING 9.12 Service Analyzer Charts (cont.) Moisture causing valve to stick open. Recover refrigerant, replace filter-drier, evacuate system, and recharge. Dirt or foreign material causing valve to stick Recover refrigerant, replace filter-drier, remove EXV open and purge with nitrogen, evacuate system, and recharge. If EXV is completely clogged use the VSODC to open the EXV, and purge with nitrogen, replace filter drier, and recharge.
  • Page 71 9.0 DIAGNOSTICS & TROUBLESHOOTING 9.12 Service Analyzer Charts (cont.) ELECTRONIC EXPANSION VALVES (cont.) SYMPTOM POSSIBLE CAUSE REMEDY Unequal evaporator circuit loading Ensure airflow is equally distributed through Superheat is low evaporator. to normal with low suction pressure Check for blocked distributor tubes. Low load or airflow entering evaporator coil Ensure blower is moving proper air CFM.
  • Page 72 9.0 DIAGNOSTICS & TROUBLESHOOTING 9.13 Troubleshooting Tips COOLING MODE TROUBLESHOOTING TIPS INDICATORS SYSTEM SUPERHEAT SUBCOOLING DISCHARGE SUCTION PROBLEM Normal: 5°–15°F Normal: See PRESSURE PRESSURE [2.8° – 8.3°C] Charging Chart Overcharge High High High Undercharge High Liquid Restriction High High (Filter Drier) Dirty Outdoor Coil High High...
  • Page 73: Outdoor Unit Maintenance

    10.0 OUTDOOR UNIT MAINTENANCE 10.1 Outdoor Coil Cleaning The outdoor fan draws air across the coil during an angle. Washing from the top of the coil down operation which results in contaminants collecting from the inside out is the most effective method of on and between the aluminum fins.
  • Page 74: Wiring Diagram

    11.0 WIRING DIAGRAM UTIL UTIL 2...
  • Page 75: Appendix

    12.0 APPENDIX 12.1 Agency Performance Audit Test Instructions Performance audit testing a 20 SEER variable d. The “Yes” should turn to a value of “No.” speed heat pump rated combination requires an 6. Once the dehumidification feature is turned Digital Control Center (according to the AHRI rating off, the Aux 1 configuration needs to be set to database) as an accessory to obtain the rated normally closed (N.C.) as to permit a closed...
  • Page 76 12.0 APPENDIX 12.1 Agency Performance Audit Test Instructions (cont.) appears at the bottom of the “installer a. To turn the unit off either press the blue checkout” screen. Then press the “Stop” down button until “stop test” appears at the button.

This manual is also suitable for:

Fo2420rvjcabFo3620rvjcabFo4820rvjcabFo6020rvjcab