5/22/2018 T252 - 69 NT20-284 69NT40-461-464

1/120

Models69NT20-28469NT40-46169NT40-464

T-252-05 $6.00

5/22/2018 T252 - 69 NT20-284 69NT40-461-464

2/120

Carrier Transicold Division, Carrier Corporation, P.O. Box 4805, Syracuse, N.Y. 13221

SERVICE MANUALOPERATION AND

! Carrier Corporation 1993 D Printed in U. S. A. 0393

CONTAINER REFRIGERATION UNIT

MODELS69NT20-284

69NT40-46169NT40-464

5/22/2018 T252 - 69 NT20-284 69NT40-461-464

3/120

i

TABLE OF CONTENTS

Section Page

1 DESCRIPTION 1-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1.1 Introduction 1-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1.2 General Description 1-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1.3 Refrigeration SystemData 1-8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1.4 Electrical Data 1-8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1.5 Safety Override Thermostat (Optional) 1-9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1.6 Voltage Switch A nd Power Transformer (Optional) 1-9. . . . . . . . . . . . . . . . . . . . . . .

1.7 Humidistat (Optional) 1-9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1.8 Fresh Air Makeup Vent 1-9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1.9 Digital Temperature Display 1-10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1.10 Safety And Protective Devices 1-10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1.11 Refrigeration Circuit 1-11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1.12 Water-Cooled Condenser And Water PressureSwitch (Optional) 1-11. . . . . . . . . . . .

1.13 Remote Monitoring Receptacle And Circuit 1-12. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1.14 Suction Solenoid Valve (Model 69NT40) 1-12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1.15 Frost Formation On Compressors 1-12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1.16 Controller 1-12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

2 OPERATION 2-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

2.1 Pre-Trip Inspection (Before Starting) 2-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

2.2 Starting And Stopping Instructions 2-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

2.3 After Starting Inspection 2-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

2.4 Unit Operation 2-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

2.4.1 Cooling --- Controller Set Below ---10_C (+14_F) 2-2. . . . . . . . . . . . . . . .

2.4.2 Controller Set Above ---10_C (+14_F) 2-2. . . . . . . . . . . . . . . . . . . . . . . . .

2.4.3 Defrost 2-5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3 TROUBLESHOOTING 3-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3.1 Unit Will Not Start Or Starts Then Stops 3-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3.2 Unit Runs But Has Insufficient Cooling 3-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3.3 Unit Operates L ong Or Continuously In Cooling 3-1. . . . . . . . . . . . . . . . . . . . . . . . .

3.4 Unit Will Not Heat Or Has Insufficient Heating 3-2. . . . . . . . . . . . . . . . . . . . . . . . . .

3.5 Unit Will Not Terminate Heating 3-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3.6 Unit Will Not Defrost Properly 3-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3.7 Abnormal Pressures (Cooling) 3-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3.8 Abnormal Noise Or Vibrations 3-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3.9 Temperature Controller Malfunction 3-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3.10 No Evaporator A ir Flow Or Restricted Air Flow 3-3. . . . . . . . . . . . . . . . . . . . . . . . . .3.11 Expansion Valve Malfunction 3-4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3.12 Water-Cooled Condenser Or Water Pressure Switch Malfunction 3-4. . . . . . . . . . .

3.13 Step-Up Power Transformer Malfunction 3-4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

5/22/2018 T252 - 69 NT20-284 69NT40-461-464

4/120

ii

TABLE OF CONTENTS(CONTINUED)

Section Page

4 SERVICE 4-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4.1 RemovingThe Refrigerant 4-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4.2 Refrigerant L eak Checking 4-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4.3 Evacuation And Dehydration 4-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4.3.1 General 4-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4.3.2 Preparation 4-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4.3.3 Procedure 4-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4.4 Adding Or Checking The Refrigerant Charge 4-2. . . . . . . . . . . . . . . . . . . . . . . . . . . .

4.4.1 Checking The Refrigerant Charge 4-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4.4.2 Adding Refrigerant To System (Full Charge) 4-2. . . . . . . . . . . . . . . . . . . .

4.4.3 A dding Refrigerant To System (Partial Charge) 4-2. . . . . . . . . . . . . . . . . .

4.5 Replacing The Compressor 4-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4.6 Compressor Disassembly 4-4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4.7 Compressor Reassembly 4-6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4.8 Checking The Compressor Oil L evel 4-7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4.9 Checking Or Replacing Moisture-L iquid I ndicator 4-8. . . . . . . . . . . . . . . . . . . . . . . .4.10 CheckingOr Replacing The Filter-Drier 4-8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4.11 Checking Or Replacing High Pressure Switch 4-9. . . . . . . . . . . . . . . . . . . . . . . . . . . .

4.11.1 Replacing High Pressure Switch 4-9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4.11.2 Checking High Pressure Switch 4-9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4.12 Servicing Quench Solenoid Valve (QV) 4-9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4.13 Replacing The E vaporator Coil A nd H eater A ssembly 4-10. . . . . . . . . . . . . . . . . . . . .

4.14 Replacing The E vaporator Fan A nd M otor A ssembly 4-10. . . . . . . . . . . . . . . . . . . . . .

4.15 Servicing The Evaporator Coil Heaters 4-10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4.16 Checking Calibration Of The Defrost A ir Switch 4-10. . . . . . . . . . . . . . . . . . . . . . . . .

4.17 Condenser Coil 4-11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4.18 Condenser Fan And Motor Assembly 4-11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4.19 Recording Thermometer (Partlow) 4-11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4.20 Recording Thermometer (Saginomiya) 4-13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4.21 Recording Thermometer (Fuji Kiki) 4-14. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4.22 Rust Prevention A nd M aintenance O f Painted Surfaces 4-14. . . . . . . . . . . . . . . . . . . .

4.23 Servicing The Water-Cooled Condenser 4-14. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4.24 Checkout Procedure For Optional Power Transformer 4-16. . . . . . . . . . . . . . . . . . . . .

4.25 Servicing The Modulating Solenoid Valve 4-16. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4.26 Controller Checkout Procedure 4-17. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4.26.1 Controller Pre-Trip 4-17. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4.26.2 Temperature Control Board Checkout Procedure With TCSM 4-18. . . . .

4.26.3 Replacing The Unit M ain Control Board 4-19. . . . . . . . . . . . . . . . . . . . . . .

4.26.4 Printed C ircuit Board C leaning Procedure 4-19. . . . . . . . . . . . . . . . . . . . . .

4.26.5 TemperatureSet Station Checkout Procedure 4-19. . . . . . . . . . . . . . . . . . .

4.26.6 TemperatureController Sensor Checkout Procedure 4-20. . . . . . . . . . . . .

4.26.7 Replacing Temperature Sensor 4-20. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4.27 Thermostatic Expansion Valve 4-20. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4.28 Evaporator Fan Motor Capacitors 4-21. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4.29 Humidistat 4-22. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

5 ELECTRICAL WIRING SCHEMATIC AND DIAGRAMS 5-1. . . . . . . . . . . . . . . . . .

5.1 Introduction 5-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

5/22/2018 T252 - 69 NT20-284 69NT40-461-464

5/120

iii

LIST OF ILLUSTRATIONS

Figure Page

1-1 Refrigeration Unit --- Front 1-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1-2 Refrigeration Unit --- Rear (Panels Removed) 1-4. . . . . . . . . . . . . . . . . . . . . . . . . . . .

1-3 Water-Cooled Condenser/Receiver Section 1-5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1-4 Control Box And Controller (Units With Two-Speed Evaporator Motors) 1-6. . . .

1-5 Control Box And Controller (Units With One-Speed Evaporator Motors) 1-7. . . .1-6 Refrigeration Circuit 1-11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1-7 Frost Pattern On Compressors 1-12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1-8 Current Control Printed Circuit Board 1-13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1-9 Controller Set Point Below ---10_C (+14_F) (Return A ir Control) 1-16. . . . . . . . . . .

1-10 Controller Set Point Above ---10_C (+14_F) (Supply Air Control) 1-16. . . . . . . . . . .

2-1 Cooling --- Within2_C (3.6_F) Of Set Point 2-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

2-2 Heating --- Within 2_C (3.6_F) Of Set Point 2-4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

2-3 Defrost 2-5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4-1 Vacuum Pump Connections 4-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4-2 Compressor --- Model 06DR 4-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-3 Oil Pump 4-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4-4 Exploded View Of Valve Plate Assembly 4-4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4-5 Bottom Plate Removed 4-4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4-6 Vane Oil Pump And Bearing Head 4-5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4-7 Gear Oil Pump And Bearing Head 4-5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4-8 Motor End Cover 4-5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4-9 Crankshaft Assembly 4-6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4-10 Removing Equalizing Tube A nd L ock Screw A ssembly 4-6. . . . . . . . . . . . . . . . . . . . .

4-11 Terminal Mounting Assembly 4-6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4-12 Suction Valve And Positioning Springs In Place 4-7. . . . . . . . . . . . . . . . . . . . . . . . . . .

4-13 Piston Rings 4-7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-14 Typical Setup For Testing High Pressure Switch 4-9. . . . . . . . . . . . . . . . . . . . . . . . . . .

4-15 Evaporator Fan L ocating Dimension 4-10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4-16 Defrost Air Switch Test Set-Up 4-11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4-17 Partlow Recording Thermometer 4-12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4-18 Saginomiya Recording Thermometer 4-13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4-19 Fuji Kiki RecordingThermometer 4-14. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4-20 Water-Cooled Condenser Cleaning 4-15. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4-21 Modulating Solenoid Valve 4-17. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4-22 Unit Control Board 4-19. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4-23 Temperature Set Station And Plug 4-20. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4-24 Sensor 4-20. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-25 Sensor And Cable Assembly 4-20. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4-26 Thermostatic Expansion Valve 4-21. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4-27 Humidistat 4-22. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

5/22/2018 T252 - 69 NT20-284 69NT40-461-464

6/120

iv

LIST OF ILLUSTRATIONS (CONTINUED)Figure Page5-1 Electrical Wiring Schematic (M odel 69NT20-284) 5-2. . . . . . . . . . . . . . . . . . . . . . . . .

5-2 Electrical Wiring Diagram(Model 69NT20-284) 5-4. . . . . . . . . . . . . . . . . . . . . . . . . .

5-3 Electrical Wiring Schematic (M odel 69NT40-464) 5-6. . . . . . . . . . . . . . . . . . . . . . . . .

5-4 Electrical Wiring Diagram(Model 69NT40-464) 5-8. . . . . . . . . . . . . . . . . . . . . . . . . .

5-5 E lectrical Wiring Schematic (M odel 69NT 40-464-1) 5-10. . . . . . . . . . . . . . . . . . . . . . .

5-6 Electrical Wiring Diagram (M odel 69NT40-464-1) 5-12. . . . . . . . . . . . . . . . . . . . . . . .

5-7 E lectrical Wiring Schematic (M odel 69NT 40-464-2) 5-14. . . . . . . . . . . . . . . . . . . . . . .5-8 Electrical Wiring Diagram (M odel 69NT40-464-2) 5-16. . . . . . . . . . . . . . . . . . . . . . . .

5-9 Electrical Wiring Schematic (Model 69NT40-464-8)(Units with S/N 90105284 thru 90105383) 5-18. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

5-10 Electrical WiringDiagram(Model 69NT40-464-8)(Units with S/N 90105284 thru 90105383) 5-20. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

5-11 Electrical Wiring Schematic (Model 69NT40-464-8) (Unitsstartingwith S/N 90105384) 5-22

5-12 Electrical Wiring Diagram (Model 69NT40-464-8) (Units starting with S/N 90105384) 5-24

5-13 E lectrical Wiring Schematic (M odel 69NT 40-464-3) 5-26. . . . . . . . . . . . . . . . . . . . . . .

5-14 Electrical Wiring Diagram (M odel 69NT40-464-3) 5-28. . . . . . . . . . . . . . . . . . . . . . . .

5-15 Electrical WiringSchematic(Model 69NT20-284-1 & -284-2) 5-30. . . . . . . . . . . . . . .

5-16 Electrical WiringDiagram(Model 69NT20-284-1& -284-2) 5-32. . . . . . . . . . . . . . . .5-17 E lectrical Wiring Schematic (M odel 69NT 40-464-4) 5-34. . . . . . . . . . . . . . . . . . . . . . .

5-18 Electrical Wiring Diagram (M odel 69NT40-464-4) 5-36. . . . . . . . . . . . . . . . . . . . . . . .

5-19 E lectrical Wiring Schematic (M odel 69NT 40-464-5) 5-38. . . . . . . . . . . . . . . . . . . . . . .

5-20 Electrical Wiring Diagram (M odel 69NT40-464-5) 5-40. . . . . . . . . . . . . . . . . . . . . . . .

5-21 E lectrical Wiring Schematic (M odel 69NT 20-284-3) 5-42. . . . . . . . . . . . . . . . . . . . . . .

5-22 Electrical Wiring Diagram (M odel 69NT20-284-3) 5-44. . . . . . . . . . . . . . . . . . . . . . . .

5-23 Electrical WiringSchematic (Model 69NT40-464-7& 69NT40-461-7, -8) 5-46. . . . .

5-24 Electrical WiringD iagram(M odel 69NT40-464-7& 69NT40-461-7, -8) 5-48. . . . . . .

5-25 Electrical WiringSchematic(Model 69NT40-464-9, -15) 5-50. . . . . . . . . . . . . . . . . . .

5-26 E lectrical Wiring Diagram (M odel 69NT 40-464-9, -15) 5-52. . . . . . . . . . . . . . . . . . . .

5-27 E lectrical Wiring Schematic (M odel 69NT 40-464-10) 5-54. . . . . . . . . . . . . . . . . . . . . .5-28 E lectrical Wiring Diagram (M odel 69NT 40-464-10) 5-56. . . . . . . . . . . . . . . . . . . . . . .

5-29 E lectrical Wiring Schematic (M odel 69NT 40-464-12) 5-58. . . . . . . . . . . . . . . . . . . . . .

5-30 E lectrical Wiring Diagram (M odel 69NT 40-464-12) 5-60. . . . . . . . . . . . . . . . . . . . . . .

LIST OF TABLES

Table Page

1-1 Model Chart 1-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1-2 Compressor M odel Number Significance Chart 1-2. . . . . . . . . . . . . . . . . . . . . . . . . .

1-3 Safety And Protective Devices 1-10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1-4 Current L imiting Switch Positions And A mperages 1-13. . . . . . . . . . . . . . . . . . . . . . .

2-1 Electrical Control Positions --- Above ---10_C (+14_F) 2-6. . . . . . . . . . . . . . . . . . . .2-2 Electrical Control Positions --- Below ---10_C (+14_F) 2-7. . . . . . . . . . . . . . . . . . . . .

4-1 Partlow Bulb Temperature --- Resistance Chart 4-22. . . . . . . . . . . . . . . . . . . . . . . . . . .

4-2 Selector Settings And Resistance 4-23. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4-3 Recommended Bolt Torque Values 4-23. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4-4 Wear Limits For Compressors 4-24. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4-5 Compressor Torque Values 4-25. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4-6 Sensor D.C. Voltages 4-25. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4-7 Temperature-Pressure Chart --- R-12 4-26. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

5/22/2018 T252 - 69 NT20-284 69NT40-461-464

7/120

1-1

SECTION 1

DESCRIPTION

1.1 INTRODUCTION

This manual contains Operating Data, ElectricalData andServiceInstructions for the refrigeration unitslisted in Table 1-1. Also Table 1-1 charts most of thesignificant differencesbetween these models.

The unit, of lightweight aluminum frameconstruction, is an all electric, one piece self-containedcooling and heating refrigeration unit. The unit isdesigned to fit in the front of a container andto serve asthe container front wall. Fork lift pockets are providedfor installation and removal of the unit.

Theunit iscompletewitha charge of Refrigerant-12(T hese units can be converted to Refrigerant-22. Theelectrical schematic has an R-22 option for CDV, CHT,UV and UVT, these parts can be added to convert theunitto R-22), compressor lubricatingoil, modeindicatinglights, temperaturecontroller and is readyfor operationupon installation.

Some units are dual voltage units designed tooperate on 190/230or 380/460 vac, 3 phase, 50-60hertzpower. (Refer to Table 1-1 and section 1.6) Other unitsare designed to operate on 380/460 vac, 3 phase 50/60hertz power.

Operating control power is provided by a sinphase transformer which steps down the AC posupplyvoltage to 24 vac, 1 phase control power.

Thetemperaturecontroller isasolidstatecontro(Refer to section 1.16) Oncethetemperaturecontrois set at desired container temperature, the unit

operate automatically to maintain the destemperaturewithin veryclose limits. Thecontrol sysautomatically selects cooling, holding or heatingnecessaryto maintain thedesiredtemperaturewithincontainer.

Theunitsareequipped witha Partlowdual Simpprobe recorder or a Fuji Kiki or Saginombattery-driven recorder.

Also, these units are equipped with a digtemperature display (switchable for_C or_F). Refesection 1.9.

WARNING

Beware of unannounced starting of theevaporator and condenser fans. Do not opencondenser fangrillebefore turningpower OFFanddisconnectingpower plug.

Table1-1. Model Chart

MODELS

UNIT WEIGHT

REFRIGER-

ANT

12

LB KG LB KG

69NT20-284 1330 620 9.0 4.1 X --- --- X X --- ---69NT20-284-1 1170 531 9.0 4.1 --- --- --- --- --- --- ---

69NT20-284-2 1160 526 9.0 4.1 --- --- --- --- --- --- ---

69NT20-284-3 1285 583 12.3 5.6 --- X --- --- --- X ---

69NT40-461-7 1260 571 12.3 5.6 --- --- X --- --- X C

69NT40-461-8 1260 572 12.3 5.6 --- --- X --- --- X ---

69NT40-464 1200 545 8.8 4.0 --- A --- --- --- X ---

69NT40-464-1 1210 560 8.8 4.0 --- A --- --- X X ---

69NT40-464-2 1200 545 8.8 4.0 --- A --- --- --- X ---

69NT40-464-3 1470 667 12.0 4.4 X X --- X X --- ---

69NT40-464-4 1250 567 8.8 3.9 X --- --- X X --- ---

69NT40-464-5 1230 558 8.8 4.0 --- A --- --- --- X ---

69NT40-464-7 1260 572 12.3 5.58 --- --- X --- --- X C69NT40-464-8 1200 545 8.8 4.0 --- A --- --- --- X ---

69NT40-464-9 1240 562 8.8 4.0 --- A --- --- --- X C

69NT40-464-10 1230 558 12.3 5.6 --- --- X --- --- --- ---

69NT40-464-12 1200 545 8.8 4.0 --- A --- --- --- --- ---

69NT40-464-15 1230 558 8.8 4.0 --- A --- --- --- X ---

A --- Provision for water-cooled condenser. If water-cooled condenser is added, refrigerant charge will change.B --- Provision for step-up power transformer.C --- Provision for heat exchanger.X --- Designates item provided.

5/22/2018 T252 - 69 NT20-284 69NT40-461-464

8/120

1-2

1.2 GENERAL DESCRIPTION

a. Compressor Section

NOTE

Check the compressor Serial/M odel Numberplate for CF M displacement, refer to Table 1-2.

The compressor section includes the compressor(with high pressure switch), power cable storagecompartment, and an optional power transformer,

located to the left of the compressor.

This section also contains the modulating solenoidvalve, suction solenoid valve (69NT40), quench valve,moisture-liquid indicator, manual liquid line valve,filter-drier, pressure relief valves, an optional receiver,and the optional water-cooled condenser/receiver.

Thesupplyair temperaturesensor(STS) islocatedattheright of thecompressor.

Table1-2. Compressor Model NumberSignificanceChart

06DR2379CC19701st, 2nd &3rd DIGIT

06D Hermetic Reciprocal

4th DIGIT

R Reefer

6th &7th DIGIT VOLUME

28 28CFM

37 37CFM

41 41CFM

b. Condenser Section

The condensing section consists of a condenser fanmotor, condenser fan, and anair-cooled condenser coil.When the unit is operating with air-cooled condenser

operation, air is pulled in the bottom of the coil anddischarges horizontally through thecenter of theunit.

Some units are equipped with an optionalwater-cooled condenser (condenser/receiver) and awater pressureswitch.Thisswitchis located on thewaterinlet line.

c. Evaporator Section

The evaporator section contains the recorder bulb,controller return air sensor (RTS), thermostaticexpansion valve, evaporator fan motors and fans (2),evaporator coil and heaters, drain pan and heaters,defrost and heat termination switches, humidistat(optional), safetyoverridethermostat(optional), andthesuction solenoid thermostat (located on the fan deck,model 69NT 40 only).

The evaporator fans circulate air throughout thecontainer bypullingair in thetopof therefrigerationunitand directingtheair through theevaporator coil whereitis either heated or cooled, and then discharged out thebottomof the refrigeration unit into the container.

The evaporator coil heaters and the thermostaticexpansion valve are accessible by removing the front,lower access panel. The safety override thermostat maybe serviced by removing the rear, middle, panel. Thedefrost termination switchislocatedonthefar sideof thecoil and may be serviced by removing the rear, middle,panel or byremoving the front, upper access panel andreaching through the left hand evaporator fan venturiAFTER POWER IS TURNED OFF AND POWERPLUG DISCONNECTED.

d. Control Box

Thecontrolboxanddoorincludetheindicator lights,manual switches, temperature selector, circuit

breaker(s), relays, transformers (current limiting andcontrol) and fuses (6 amp for control and 3 amp forcontroller). (See Figure1-4 or Figure1-5) Also, locatedabove the temperature selector is the defrost intervalselector.

5/22/2018 T252 - 69 NT20-284 69NT40-461-464

9/120

1-3

1. Access Panel (Evaporator Fan Motor #2)

2. Access Panel (Heater Location)

3. TIR Locking Devices

4. Recording Thermometer5. Make-Up Air Cover

6. Unit Serial/Model No. Plate --- Location

7. Power Cables and Plug

8. Power Transformer --- Location

9. Discharge Service Valve

10. Compressor Sight Glass

11. High Pressure Switch

12. Compressor

13. Remote Monitoring Receptacle (RM)

14. Manual Defrost Switch15. Start-Stop Switch

16. Condenser Fan and Motor

17. Fork Lift Pockets

18. Thermostatic Expansion Valve --- Location

19. Access Panel (Evaporator Fan Motor #1)

1

2

3

4

5

6

7

8

9 10 11 12 13

Figure1-1. RefrigerationUnit --- Front

5/22/2018 T252 - 69 NT20-284 69NT40-461-464

10/120

1-4

1. Evaporator Fan Motor #1

2. Humidistat --- Location (Optional)

3. Air Pressure Switch4. Suction Solenoid Thermostat --- Location

(69NT40)

5. Evaporator Coil

6. Evaporator Fan Motor #2

7. Recording Thermometer Bulb

8. Return Air Temperature Sensor

9. Evaporator Coil Heaters

10. Defrost Termination Thermostat11. Heater Termination Thermostat

12. Drain Pan Heater

13. Safety Override Thermostat --- Location

(Optional)

Figure1-2.Refrigeration Unit --- Rear (Panels Removed)

1 2 3 4 5 6 7 8

910111213

5/22/2018 T252 - 69 NT20-284 69NT40-461-464

11/120

1-5

12 11

SIDE VIEW

5421

14

1. Suction Service Valve

2. Supply Air Temperature Sensor

3. Water-Cooled Condenser/Receiver

4. Sight Glass5. Water Pressure Switch --- Location

6. Filter-Drier

7. Quench Valve (Solenoid) or

Quench Valve (Thermostatic Expansion)

8. Moisture-Liquid Indicator

9. Liquid Line and Charging Valve

10. Suction Solenoid Valve (69NT40)

11. Modulating Solenoid Valve12. High Side Pressure Relief Valve

13. Low Side Pressure Relief Valve

14. Receiver

3

Figure1-3. Water-CooledCondenser/Receiver Section

13

6

7

10

5/22/2018 T252 - 69 NT20-284 69NT40-461-464

12/120

1-6

UNITSWITH TWO-SPEED EVAPORATOR MOTORS

1. Power Supply and In-Range Board

2. Timing and Current Control Board

3. Temperature Control Board

4. Fuse Location (3A)

5. Temperature Simulator Switch

6. Defrost Interval Selector

7. Set Temperature Display Switch

8. Time Delay Override Switch

9. Temperature Selector

10. Condenser Fan Motor Relay

11. Hour Meter (Optional)

12. Heat Relay

13. Compressor Contactor

14. Evaporator Fan Motor Relay --- High Speed

15. Evaporator Fan Motor Relay --- Low Speed

16. Voltage Switch

17. Circuit Breaker (230v)

18. Circuit Breaker (460v)

19. Control Fuse (6A)

20. Control Transformer

21. Current Limiting Transformer --- Location

22. Digital Temperature Display

23. Humidistat Control Switch (Optional)

24. Scale Selector Switch

25. Relay (24 vac w/12 vdc coil)

26. Main Control Board

27. Contol Relays (CR & KR) (Optional)

Figure1-4.Control BoxandController (Units with Two-SpeedEvaporator Motors)

4

6

0

1 2 3 4 5 9 10

17

181920212225

26

7 12 13

14

16

6 8 11

15

2324

27

5/22/2018 T252 - 69 NT20-284 69NT40-461-464

13/120

1-7

UNITS WITH ONE-SPEED EVAPORATOR MOTORS

1. Power Supply and In-Range Board

2. Timing and Current Control Board

3. Temperature Control Board

4. Fuse Location (3A)

5. Temperature Simulator Switch

6. Defrost Interval Selector7. Time Delay Override Switch

8. Set Temperature Display Switch

9. Temperature Selector

10. Condenser Fan Motor Relay

11. Evaporator Fan Motor Relay

12. Heat Relay

13. Compressor Contactor

14. Voltage Switch

15. Circuit Breaker (230v)

16. Circuit Breaker (460v)

17. Control Fuse (6A)

18. Control Transformer --- Location19. Current Limiting Transformer

20. Digital Temperature Display

21. Scale Selector Switch

22. Relay (24 vac w/12 vdc coil)

23. Main Control Board

Figure1-5. Control BoxandController (UnitswithOne-SpeedEvaporator Motors)

1 2 3 4 5 6 7 8 9 10 11 12 13

14

15

16171819202122

23

5/22/2018 T252 - 69 NT20-284 69NT40-461-464

14/120

1-8

1.3 REFRIGERATION SYSTEM DATA

a. Compressor --- Motor Assembly

No. of Cylinders: 6Model: 06DRWeight (Dry): 132 kg(290 lb)

b. ApprovedCompressor Oil

PetroleumSpecialtiesInc. --- Cryol 150Witco --- Suniso 3GSTexaco --- Capella WF32

c. Compressor Oil Charge

4.0liters (8.5U.S. Pints)

d. Compressor Oil SightGlass

Oil level should be between 1/4to 1/2of thesight glass with thecompressor in operation.

e. DefrostAir PressureSwich

Initiates at: 20.3 1.8mm WG(0.80 .07 inch)

f. DefrostTimer

Initiates Defrost: Refer to paragraph 1.16.m.

g. DefrostTermination Thermostat

Opens: 23.9 ( 3)_C = 75( 5)_FCloses: 15.6 ( 3)_C = 60( 5)_F

h. Expansion ValveSuperheat

Settingat0_C (32_F) containerboxtemperature:4.4to 5.5_C (8to 10_F)

i. Heater Termination Thermostat

Opens: 54 ( 3)_C = 130 ( 5)_FCloses: 38 ( 3)_C = 100 ( 5)_F

j. High PressureSwitch

28 or 37 CFM Compressor:Cutout: 21 ( 0.7) kg/cm@= 295 ( 10) psigCut-In: 13 ( 0.7) kg/cm@= 190 ( 10) psig41 CFM Compressor:Cutout: 25 ( 0.7) kg/cm@= 350 ( 10) psigCut-In: 18 ( 0.7) kg/cm@= 250 ( 10) psig

k. Refrigeration Charge

Refer to Table 1-1

l. RefrigerantPressureRelief Valves

L ow Side Valve:Opens: 18.63kg/cm@(265psig)

H igh Side Valve:Opens: 34.10kg/cm@(485psig)

m. RefrigerantOperatingLevel (after 20minutesoperation with unit in cooling)

Refer to section 4.4

n. Unit Weight

Refer to Table 1-1

o. Water PressureSwitch

Cut-In: 0.5 0.2kg/cm@(7 3 psig)Cutout: 1.6 0.4kg/cm@(22 5 psig)

p. Suction SolenoidThermostat (69NT40)

Closesat: ---12.2 1.7_C (10 3_F)Opensat: ---6.7 3.3_C (20 6_F)

1.4 ELECTRICAL DATA

a. Circuit Breaker(s)

CB-1 Trips at: 24.2AmpsCB-2 Trips at: 50.0Amps

b. Compressor Motor

Full L oad Amps(FL A) (Model 69NT40): 17.6A mps@ 460 vac (with current limitingswitch in position B)

c. Condenser Fan Motor

Bearing Lubrication: Factory lubricated, additionalgrease not required.

Full L oad Amps: 2.0/4.0FL ANominal Horsepower: 0.43/0.75 hpRotation: CCW when viewed fromshaft end.Speed: 1425/1725Voltage: 190/380/208/230/460vac/1ph/50/60hz

d. DrainPanHeaters

Number of Heaters: 1Rating: 750 watts+5 /---10 % at 460 VacResistance (cold): 22.7 5% ohms nominalType: Sheath

e. Evaporator Coil Heaters

Number of Heaters: 4Rating: 750 watts each at 230 +5 /---10 voltsResistance(cold)@20_C(68_F )A mbient:66.8to

77.2 ohmsType: Sheath

f. Evaporator Fan Motor(s)

Bearing Lubrication: Factory lubricated, additionalgrease not required.

Full L oad Amps:High Speed: 2.0/2.3 AmpsL ow Speed: 0.4/0.6 AmpsSingle Speed Motor: 2.01/4.0

Nominal Horsepower:High Speed: 0.58/1.0 hpL ow Speed: 0.07/0.12 hpSingle Speed Motor: 0.58/1.0 hp

Rotation:Evaporator Fan Motor #1 (See Figure1-2): CW when

viewed from shaft end/CCW when viewed from endopposite shaft end.

Evaporator Fan Motor #2 (See Figure1-2): CCWwhen viewed from shaft end/CW when viewed from endopposite shaft end.

Speed: 2850/3450rpm

Voltage: 380/460vac/1 ph/50/60 hz

g. Fuses

Control Circuit:Amps: 6 amp

Unit Control Board:Amps: 3 amp

5/22/2018 T252 - 69 NT20-284 69NT40-461-464

15/120

1-9

1.5 SAFETY OVERRIDE THERMOSTAT(OPTIONAL)

Thisthermostat isfixed at ---3.9_C (25_F) toprovidea low temperature limit on the evaporator supply air(discharge air) when transporting perishablecommodities.

Whenthetemperaturecontrollerissetbelow ---10_C(14_F), the safety override thermostat is bypassed asrelay TU is de-energized and contacts T36 to T35 are

closed, refer to section 5.

For thermostat location see Figure 1-2.

1.6 VOLTAGE SWITCH AND POWERTRANSFORMER (OPTIONAL)

WARNING

Do not attempt to remove power plug(s) beforeturning OFF start-stop switch (ST), unit circuitbreaker(S)andexternal power source.Makesurethe power plugs are clean and dry beforeconnectingtoanypower receptacle.

a. Step-Up Power Transformer

The transformer is located under the condenser coil(left-hand side of unit) and the purpose of thistransformer is to provide 380vac/3ph/50hz power whenthe190/230vacpowercable(black) is connected to a190vac power supplyor to provide 460 vac/3ph/60 hz whenthe190/230vacpowercable(black) is connected to a230vacpower supply.

WARNING

Do not attempt to remove power plug beforeturning OFF voltage switch (VS), start-stopswitch (ST), unit circuit breakers (CB-1 AndCB-2), and external power source.

b. ToPlaceUnit on 190/230vacPower Supply

1. Make sure voltage switch (V S) is in the OFFposition. Make sure start-stop switch (ST, on controlpanel) and circuit breakers CB-2 is in position O(OFF ). (See Figure 1-4 or Figure 1-5)

2. Connect 190/230 vac power cable plug (blackcable). Place voltage switch (VS) in the 230 v position.Place circuit breaker (CB-2) in position 1. Close andsecure control box door and then place the start-stopswitch (ST) in position 1.

c. ToPlaceUnit on 380/460vacPower Supply

1. Make sure voltage switch (V S) is in the OFFposition. Make sure start-stop switch (ST, on control

panel) and circuit breaker (CB -1) is in position O.(OFF).

2. Connect 380/460 vac power cable plug (yellowcable). Place voltage switch (VS) in the 460 v position.Place circuit breaker (CB-1) in position 1. Close andsecure control box door and then place the start-stopswitch (ST) in position 1.

1.7 HUMIDISTAT (OPTIONAL)

NOTE

The supply air must be in-range or humidistatcircuit will not energize.

The humidistat (Figure1-2) is factory set at relative humidity (R.H.) and is designed to operate wtransporting a chill load (controller set above ---1(14_F) and is locked out when the controller is set be---10_C (TU contactsT35to T37are open).

a. Thehumidistat will bein operation if:

1. Supply air is in-range (in-range light illuminated

2. Humidistat control switch in the ON positio

3. Controller is set above ---10_C (14_F).

4. Container relative humidity reaches the 7R.H. setting of humidistat.

The above energizes the humidistat circuit as rIRS contactsT24 to T23, TU relay contactsT35to THCS contacts1-2, andHC contacts1-3close to enertheheaters and heat light.

b. For testingpurposes:

WARNING

Beware of rotating evaporator fan whenconductingfollowingtest.

1. Remove the front evaporator fan motoraccess panel (see Figure 1-1). The humidistat is locabehind this panel.

2. Move the controller set pointer within (3.6_F) of container supplyair temperature.

3. Move the humidistat control switch to position (position 1).

4. Turn the humidistat control knob until heaare energized (heat light ON) and then reset contro70% R.H. Replace access panel and lockwire.

1.8 FRESH AIR MAKEUP VENT

The purpose of the vent is toprovide ventilationcommoditiesthat require fresh air circulation and mbe closedwhen transporting frozen foods.

0

30

60

90

120

150

180

210

240

0 10 20 30 40 50 60 70 80 90 100

AIRFLOW(CMH)

1-!

PERCENT OPEN

69NT40 FRESH AIR MAKEUP

T-

2-%

3T-

T-

ZERO EXTERNAL STATIC 50HZ

For 60HZ operation multiply curves by 1.2

5/22/2018 T252 - 69 NT20-284 69NT40-461-464

16/120

1-10

Table1-3. SafetyandProtectiveDevices

UNSAFE CONDITIONS SAFETY DEVICES DEVICE SETTING

1. Excessive current draw 1. Circuit Breaker (CB-1) ---Manual Reset

1. Trips at 24.2 amps(460 vac)

1. Circuit Breaker (CB-2) ---Manual Reset

1. Trips at 50 amps(230 vac)

2. Excessive current draw on control circuit 2. Fuse 2. Opens at 6 amps

3. Excessive condenser fan motorwinding temperature

3. Internal Protection (IP-CM) ---Automatic Reset

3. N/A

4. Excessive compressor motor windingtemperature

4. Internal Protector (IP-CP) ---Automatic Reset

4. N/A

5. Excessive evaporator fan motor(s)winding temperature

5. Internal Protector(s) (IP-EM) ---Automatic Reset

5. N/A

6. Abnormally low refrigerant temperature 6. Low Side PressureRelief Valve

6. Opens at 18.63 kg/cm@(265 psig)

7. Abnormally high refrigerant temperature 7. High Side PressureRelief Valve

7. Opens at 34.10 kg/cm@(485 psig)

8. Abnormally high discharge pressure 8. High Pressure Switch --- 28 or37 CFM

8. Opens at 21 0.7 kg/cm@(295 10 psig)

8. High Pressure Switch --- 41 CFM 8. Opens at 25 0.7 kg/cm@(350 10 psig)

9. Solid state circuitry high voltage surge 9. Fuse (F1) 9. Opens at 3 amps10. Excessive power transformer winding

temperature10. Over Temperature Sensor ---

Automatic Reset10. Opens at 178 5_C

(350 10_F)Closes at 150 7_C(300 12_F)

11. Return air temperature below ---3.9_C(25_F) Set points above ---10_C = 14_F

11. Safety override temperature 11. Opens to stop the unit

a. Full Open or Closed Positions

Maximumair flow is achieved bylooseningthe wingnutsandmovingthecovertothemaximumopenposition(100% position). The closed position is 0% air flowposition.

Theoperator mayalso adjust theopeningtoincreaseor decrease the air flowvolume to meet the required airflow.

b. Air Samplingfor Carbon Dioxide(CO2) Level

L oosen wingnutsand move cover until thearrowonthecover is alignedwith theatmosphere samplingportlabel. Tighten wing nuts and attach 3/8 tube to thesamplingtube.

If the internal atmosphere content has reached anunacceptable level, the operator may adjust the coveropeningtomeet therequiredair flowvolumetoventilatethe container.

1.9 DIGITAL TEMPERATURE DISPLAYThedigital temperaturedisplayreceivessignalsfrom

the controller and normally displays temperature at theactive controller probe (return air temperature sensorRTS or supplyair temperature sensor STS).

Depressing theset display switch (SDS, momentarycontact) will displaythecontroller set pointtemperaturewhile depressed.

Displayisselectablein celsiusor fahrenheit. Placingthescale selector switch in thedown position causes thetemperature to bedisplayed in degrees fahrenheit (_F).

Display will read in degrees centigrade (_C) with theswitch in the up position.

With perishable cargo (set points above ---10_C =14_F) the digital temperature display and recordingthermometer may not agree as the recorder bulb is

sensing the return air temperature and the digitaltemperaturedisplaywill indicatesupplyair temperature.

Withafrozenload(setpointsbelow---10_C = 14_F),the recording thermometer and the digital temperatureboth indicate return air temperature and should be inclose agreement.

1.10 SAFETY AND PROTECTIVE DEVICES

System components are protected from damage bysafety and protective devices listed in Table 1-3. Thesedevices monitor the system operating conditions andopenasetof electrical contactswhenanunsafecondition

occurs.

Open safety switch contacts of one or more of thefollowingdevicesIP-CM, IP-CP, HPS, or IP-Trans(Auto)will shutdown thecompressor. Thecondenser fanmotorwill stop if contacts IP-CM, IP-CP, or IP-Trans (Auto)open.

Theentire refrigeration systemwill shut down if oneof the following safety devices open: (a) CircuitBreaker(s) or; (b) Fuse (6A) or; (c) Evaporator FanMotor Internal Protector(s) --- (IP-EM ).

5/22/2018 T252 - 69 NT20-284 69NT40-461-464

17/120

1-11

1.11 REFRIGERATION CIRCUIT

Starting at the compressor (see Figure 1-6), thesuction gas is compressed to a higher temperature andpressure.

1. Suction Service Valve2. Discharge Service Valve3. Air-Cooled Condenser4. Water-Cooled Condenser or Receiver5. Sight Glass6. Water Outlet7. Water Inlet8. Pressure Relief Valve (High Side)9. Pressure Relief Valve (Low Side)

10. Liquid Line Valve11. Filter-Drier12. Moisture-Liquid Indicator13. Expansion Valve14. External Equalizer Line

15. Expansion Valve Bulb16. Evaporator17. Suction Solenoid Valve (69NT40)18. Modulating Solenoid Valve19. Quench Valve (Solenoid or Thermostatic)

18

2

16

8

71

3

4

10

56

9

11

13

14

15

17

19

12

Figure1-6.Refrigeration Circuit

When operating with theair-cooled condenser, thegas flows through the discharge service valve into theair-cooled condenser. Air flowingacrossthecoil finsandtubes cools the gas to saturation temperature. Byremoving latent heat, the gas condenses to a hot liquidand then flows to the water-cooled condenser/receiverwhich stores the additional charge necessary for low

temperature operation.When operatingwiththewater-cooled condenser, the

hot gasflows through theair-cooled condenser and intothewater-cooled condenser. Theheat flowsfromthehotgas into the condenser coolant thus cooling thecompressed gas and changing the state of refrigerantfrom a gas to a liquid.

From the condenser/receiver, the liquid refrigerantflows by a pressure relief valve which opens if therefrigerant pressure is abnormally high.

Theliquidrefrigerant continuesthroughaliquidshutoff valve, filter-drier (which keeps refrigerant cand dry), a moisture-liquid indicator and then tothermostatic expansion valve. A s the liquid refrigepassesthroughtheorificeof theexpansion valve somit vaporizes into a gas (flash gas). Heat is absorbed fthe evaporator air by the balance of the liquid causinto vaporizein the evaporator coil. Thevapor then flthrough thesuction line to thecompressor.

Thethermostaticexpansionvalvebulbonthesuc

line near the evaporator coil outlet, controls the vamaintaining a relatively constant superheat at theoutlet regardlessof load conditionsexcept atabnormhigh container temperatures such as during pulldo(valveat maximumoperatingpressure condition).

1.12 WATER-COOLED CONDENSER ANDWATER PRESSURE SWITCH(OPTIONAL)

The water-cooled condenser is used when heathe surrounding air is objectionable such as in a shhold and coolingwater is available.

The water-cooled condenser is of the shell and

typewith circulatingwater through thecupro-nickelThe refrigerant vapor is admitted to the shell side ancondensed on the outer surface of the coil.

For operation of the refrigeration unit with the water-cocondenser, do the followi ng:

a. Connect water supply line to inlet sidecondenserand dischargelineto outletside of conden

b. Maintain aflowrateof 11to 26litres(3to7 Ugallons) per minute. Thewater pressureswitchwill oto de-energize the condenser fan relay. The condefan motor will stop and will remain stopped until water pressure switch closes.

The refrigeration unit operating with water-cooled condenser will perform as outlinedsection 2.4 except that the condenser fan motostopped in all modes.

To shift to air -cooled condenser operation, do the follow

Disconnectthewater supplyandthedischargelinthe water-cooled condenser. The refrigeration unitshift to air-cooled condenser operation when the wpressure switch closes. (Refer to paragraph 1.3.o.)

5/22/2018 T252 - 69 NT20-284 69NT40-461-464

18/120

1-12

1.13 REMOTE MONITORING RECEPTACLEANDCIRCUIT

When the remote monitor is connected to theremote monitoringreceptacle, Figure 1-1, thefollowingremote circuits are energized.

Circuit Function

Sockets B to A Energizes remote cool light

Sockets C to A Energizes remote defrost lightSockets D to A Energizes remote in-range light

Note

The in-range light will be illuminated if thecontainer return air temperature is within 2_C(3.6_F). Refer to paragraph 1.16.n.

1.14 SUCTION SOLENOID VALVE(Model 69NT40)

The suction solenoid valve, shown in Figure 1-3 iscontrolledbythesuction solenoidthermostat(locatedon

the evaporator fan motor deck as shown in Figure1-2).In operation, if thereturn air temperaturedecreases

to ---12.2_C (10_F), the suction solenoid thermostat(SST) closesto energizethesuction solenoid valve,whichopens to increase the refrigerant flow rate and coolingcapacity.

The thermostat opens with increasing return airtemperature at ---7 3_C (20 6_F) to de-energizethevalve.

1.15 FROST FORMATION ON COMPRESSORS

Note

Some models have a thermostatic expansion

quench valve, so frost formation on thecompressor is not applicable. To see whichmodels use a solenoid quench valve refer tosection 5.

Frost may, in normal operation, form on thecompressor suction service valve and end bell. This iscausedbynormal quench valve operation in conjunctionwith thesuction modulation valve.F igure 1-7A showstheallowable frost limit pattern for units operatingwiththecontroller set point above ---10_C (14_F). This frostpattern is described below.

The temperature controller varies the amount of

current through thesuction modulation valve coil whichin turnincreasesor decreasestheamountof restriction inthe suction line, so that the net cooling capacity of theunit will match the coolingrequired to maintain theloadat set point.

Whenthesuction modulation valveisapproximately50% closed (approximately 0.6 amps output to thesuction modulation valve coil from the temperaturecontroller), thetemperature controller will energize thequenchsolenoid valve. Whenthequenchvalveisopened,a small amount of liquid refrigerant is metered throughan orifice (which acts as an expansion device) into the

suction linedownstreamof thesuctionmodulation valve.Because of low compressor suction pressures created bythe suction modulation valve, the liquid fed by thequench valve flashes to a low temperature gas and,therefore, the compressor may form frost or ice on theend bell and top of the motor cavity adjacent to thesuction gas path of flow. This is not harmful to thecompressor, as the restrictor in the quench valve lineprevents excessive liquid from flowing into thecompressor.

Figure AController SetAbove --10_C (14_F)

Figure BController SetBelow --10_C (14_F)

Figure1-7.FrostPattern on Compressors

With the controller set below ---10_C (14_F) theallowable compressor frost pattern limit is shown inFigure1-7B. The frost line will not normally extendbeyond the suction service valve as the quench valveshould not energize when operatingwith the controllerset point below ---10_C (14_F).

If excessive frost is noticed on the compressor andthe suction modulation system is operating normally,then the thermal expansion valve superheat settingshould be checked. Flooding by a thermal expansionvalve maycause oil to foamexcessively. Normal quenchvalve operation will not foam the oil significantly after

operation has stabilized.Adhesive-backed labels depicting allowable frost

patterns on compressors are available from CarrierTransicold Replacement Component Group.

1.16 CONTROLLER

h. General Description(SeeFigure1-4or Figure1-5)

The Carrier Transicold controller is a modularassemblyof solid stateelectronic circuits that combinesanumber of refrigeration system control functions in asingle unit.

5/22/2018 T252 - 69 NT20-284 69NT40-461-464

19/120

1-13

The functions are: (1) temperature control; (2)current control; (3) temperature control function timedelays; (4) selectable time interval defrost; and, (5)out-of-range indication time delay.

Thecontroller consistsof aprogrammedmaincircuitboard, three plug-in control circuit boards, five or sixplug-in relays, and remote located components whichare: (1) temperature set point potentiometer; (2) twotemperature sensing probes; (3) two switches for

checking calibration; and, (4) current limitingtransformer.

The controller has high precision components incritical circuits which result in the elimination ofcalibration adjustments. As long as componentreplacements are made using factory specified parts,calibration will bemaintained.

i. Model 69NT40CurrentControl(CapacityOverride)

The current control function of the controller limitsthe maximum unit current draw to prevent possible

overloading of limited power sources such as anengine-generator setwhenoperatingwithhighcontainertemperatures and high ambient temperatures. Refer toTable 1-4.

The current control function, when required, willoverridethenormal modulatedcapacitycontrol function(described in paragraph 1.16.j.) to reduce coolingcapacity sufficiently to prevent total unit current fromexceeding a preset value. This is accomplished bycircuitryon the timingand current control circuit boardin response to the current sensed in one phase of thecompressor power line by current limiting transformer(CLT). The current limit on the timing and current

control board is factory set in switch position B (seeFigure 1-8).

A

B CD

ESW1

CURRENT LIMIT SWITCH

Figure1-8. CurrentControl PrintedCircuit Board

Table1-4.CurrentLimitingSwitchPositionsandAmperages

Switch Position A B C D E

460 vac Operation 15A 17A 19A 21A 23A

230 vac Operation 30A 34A 38A 42A 46A

NOTES

1. If the current limitingswitch is set too low,unit pulldown capacity may be reduced due tolimitation of compressor amperage asdetermined by the timing and current controlboard.

2. Table 1-4shows the approximate total unitamps for each position of the current limitcontrol.

j. TemperatureControl (CapacityControl)

The temperature control portion of the controconsistsof a temperature setpoint potentiometer (Creturn air (RTS) and supply air (STS) temperasensors (two thermistor probes), solid state circu(temperaturecontrol, timingand current control, posupply and IRS printed circuit boards), and associacontrol relays. Each temperature sensor is located irespective air stream.

Operation atanydesiredtemperature within thepoint range (---25_C to +25_C or ---15_F to +80_Fachieved byturningtheset point potentiometer knoposition thepointer at thedesired temperature.

A changein sensedair temperature(supplyor reair depending on set point) causes a correspondchange in electrical resistance of the thermistor senThischangeisprocessed bytheelectroniccircuitryofcontroller which actuates control relays and refrigerant suction modulating valve in accordancewthe controller operatingdiagrams as shown in NO Tand NO TAG.

For set pointsabove---10_C (14_F) relay TU wienergized along with contactor EF. The two-spevaporator motorswill bein high speed.

Also, for set points above ---10_C (14_F),

controller will maintain supplyair attheset temperabythefollowing modes of operation:

1. Conventional, Humidity Control Switch (Hin position O --- cooling by refrigeration with sucmodulation and the compressor cycling at light loElectric resistance heating.

2. Conventional plus Dehumidification, HumiControl Switchin position 1 --- coolingbyrefrigerawith suction modulation and compressor cycling athumidities, suction modulation and simultaneelectric resistance heatingat high humidities.

1. Operationin theConventional Mode

Operation in the Conventional Mode (HCSposition O) with the set point setting below thetemperature at the supply air probe but above ---1(14_F) theunit startsin coolingwithcontroller relaysand TQ energized. Compressor and condenser contactors are energized through relay TC contactandT 3(nowclosed)andrelayT Q contactsT7to T6(closed).

As the sensed temperature continues to fall, modulatingvalvecurrentwill remain atminimum(un0.2 amp) until the sensed temperature drops to 0.2(0.45_F) above set point.

5/22/2018 T252 - 69 NT20-284 69NT40-461-464

20/120

1-14

With any further drop in sensed temperature,modulated (continuously variable) capacity reductionoccurs to match cooling requirementsthat are less thanthe maximum capacity of the unit. This permits exactbalancing of unit capacity with a wide range of coolingloads while maintaining continuous compressoroperation and holding thetemperature very close to setpoint. This variable cooling capacity is achieved by amodulating solenoid valve which provides a variablerestriction in the compressor suction line. This valve

varies the flow rate of the refrigerant pumped by thecompressor.

For low coolingcapacity operation requiringhigherthan 0.62 amp modulating valve current, the two-wayquench solenoid valve is energized (opened) whichallowsa small, metered flowof liquid refrigerant to enterthe suction line and provide supplemental compressormotor cooling.

For very small cooling requirements that are lessthantheminimumrefrigerationcapacityof theunit(fullyclosed modulating valve), the controller will cyclecompressor on and off to match the load.De-energization of relay TC to stop the compressor isdelayed to prevent nuisance cycling from brief lowtemperature swings. Once off, the compressor will notrestart for 5 to 6 minutes. (Refer to paragraph k.)

In cold ambientswhencontainer heatingisrequired,thesensed temperaturewill dropto 1.0_C (1.8_F) belowset point and the controller will cycle electric resistanceheating with a transient masking delay on energizationsimilar to that associated with compressor cycling. Theheatrelay(contactor HR) isenergizedthroughtheclosedcontacts (N.C.) of relay TC by controller relay THenergizing and closing the TH contacts (N.O.). Heatrelay(contactor) HR energizesthedefrost and drain panheaters.

For set points below ---10_C (14_F), return airtemperature is sensed and the range of capacityreduction is more limited than for higher set points.When cooling requirements are less than the minimumcontinuousoperatingcapacityof theunit, theunit revertsto on-off compressor cycling to match the load. Whencooling, compressor and condenser fan contactors areenergized through thenormallyopen (N.O.) contactsofrelay TC.

Also, for set points below ---10_C (14_F), thecontroller will maintainreturn airat thesettemperatureby refrigeration. Electric resistance heating is

electronicallylockedoutin thistemperaturerange.U nitswith two-speed evaporator fan motors will have theevaporator fan motors in low speed as relayTU will bede-energized. (Contactor ES energized.)

Electricresistanceheatingislockedoutfor setpointsbelow ---10_C (14_F) bycontroller relayT H beinglockedout to prevent energizingthecircuit.

Cargo temperatures will necessarily vary somewhatfrom controlled air temperatures. A simple numericaldifference between product temperature and controlledair temperaturecannot bestatedbecauseof thecomplex

relationship of air flow variations within the containerand temperaturegradientsof air and product. However,during cooling, it can be stated that with supply aircontrol, a minimum product temperature will beeffectively maintained and with return air control, amaximum product temperature will be effectivelymaintained.

2. Operationin theDehumidification Mode

Operation in the Dehumidification Mode (HCS in

position 1). With the set point setting below the airtemperature at the supply air probe (but above ---10_C(14_F) starts with controller relays TU and TQenergized. Thecompressor andcondenserfancontactorsareenergizedthroughnormallyclosedT C relaycontacts.The evaporator fan motors are as previously described.

Cooling capacity reduction by modulation is thesame as described for the conventional operating modewhen thereturnair relative humidityis belowthesettingon the humidity controller (HC) and as long as anout-of-range temperature condition exists, regardless ofreturn air relative humidity.

For relativehumiditieshigher thantheHC setting, if

the supply air temperature drops to 2_C (3.6_F) aboveset point, in-range relay (I RS) energizes and, in turn,energizes heat relay (contactor) HR thorough closed(N.O.) relay HC contacts. A lso, the in-range and heatlights are illuminated at this time.

This applies power to the defrost and drain panheaters. This added head load causes the controller toopen the modulatingvalve to match the new total heatload while still holding the supply air temperature veryclose to set point.

Opening the modulating valve reduces thetemperature of the evaporator coil surface whichincreasestheratewater iscondensedfromtheair passing

through the coil. Removing water from the air reducestherelative humidity until theH C settingis reached andcontroller HC contacts open to de-energize heating.

Humidity controller HC will continue to cycleheating to maintain relativehumidity below HC setting.

With set points below ---10_C (14_F), operation isthesame aspreviouslydescribed for conventional mode--- heating and dehumidification arelocked out.

k. TimeDelays

TC relay operation is affected by a time delayfunction of the Timing and Current Control Board; itspurpose is to prevent short cycling of thecompressor.

To prevent short cycling of the compressor, a sixminutecompressor off time must besatisfied. Whenthetimer completes its six minute cycle, the followingtemperature requirements must be met to allow thecompressor to start.

1. .25_C ( .45_F) from setpoint, setpointsabove ---10_C (14_F).

2. .50_C ( .9_F) fromsetpoint, setpointsbelow---10_C (14_F).

Until these temperature requirementsare met, thetimer will continue to cycle.

5/22/2018 T252 - 69 NT20-284 69NT40-461-464

21/120

1-15

Additional transient override time delays affect theoperation of TC and TH relays. These delays are alloverridden by pressing the time delay override switch(TDS).

l. LockoutFunctionsHeatingfunctionlockoutfor setpointsbelow---10_C

(14_F) is achieved by relay TH being prevented fromenergizing.

m. SelectableTimeInterval Defrost

A selectable interval defrost initiation timer isincluded in the timing and current control board. Thetimeinterval between defrost initiations(90secondtest,3 hours, 6 hours, 12 hours, or 24 hours) is set with thedefrost interval selector switch (DIS).

The controller initiates defrost (providing theevaporator coil temperature is below 13_C = 55_Frequired to close the defrost termination thermostatcontacts) by:

1. Energizingdefrost relay(DR) energizes the defrostlight and stops the evaporator fan motors byde-energizing the evaporator fan motor contactor.

2. De-energizingcoolingrelay(T C) andenergizingandheating relay (TH). This stops the compressor andcondenser fanmotor and energizesthe defrost and drainpan heaters.

Defrostingis terminated bythedefrost terminationthermostat(DTT), whichopenswhentheevaporatorcoiltemperaturerisesto 24_C (75_F) after all frost hasbeenmelted fromthe coil.

Also, defrost may be manually initiated at anytimebyactuatingthemanual defrost switch (M DS).

NOTEDefrost interval timing restarts at time zerowhenever thetime delayoverride switch(TDS)is depressed or control circuit power is restoredafter an interruption such as occurs when

stoppingor startingunit (ST switch).

n. Out-of-RangeIndicationTimeDelayDuringdefrost,thetemperatureat thesensingprobe

risesabovetheupperin-rangelimit whichwouldresultinan out-of-range indication if the temporary conditionwere notoverridden. Circuitryon thetimingand currentcontrol boardworksin conjunction with thetemperaturecontrol circuitryto delayde-energization of thein-rangerelay (I RS) until approximately 90 minutes after thetemperature at the sensing probe goes beyond thein-rangetemperaturelimits. A normal operatingunit willreturn from defrost to an in-range condition beforeexpiration of the 90 minutedelay andno interruption of

in-range indication will occur. Indication of theinstantaneous temperature condition (in orout-of-range) can beobtainedbypressingthetimedelayoverrride switch (TDS).

o. Function andCalibrationCheckThe controller has precision resistors that simulate

sensing probe temperatures to permit readily checkingcontroller functions and calibration without using

temperature baths or other temperature measuinstruments.

Sensing probe temperature is simulated byholdthe temperature simulator switch (T SS) in the desposition, 0_C (32_F) or ---17.8_C (0_F).

Whencheckingcontroller functions and calibratit is also necessaryto holdthetime delayoverridesw(TDS) depressed to obtain immediate controresponses. Depressing switch TDS does thefollowin

1. Cancels 90 minutein-range delay(paragraph n.

2. Cancels 6 minute compressor recycle delay(paragraph k.).

3. Cancels relays TC OFF and TH ON nuisacyclingdelays.(Paragraphs j. and k.).

4. Resetsdefrost interval timingto zero (paragraph n.

5/22/2018 T252 - 69 NT20-284 69NT40-461-464

22/120

1-16

RISINGTEMPERATURE

FALLINGTEMPERATURE

---1.5_C (---2.7_F)

---1_C (---1.8_F)

---0.5_C (---0.9_F)---0.25_C

0.25_C

1.5_C (2.7_F)

1_C (1.8_F)

0.5_C (0.9_F)

---2_C (---3.6_F)

SET POINT

2_C (3.6_F)

IRSEnergizes

IRSDe-energizes

IRSEnergizes

IRSDe-energizes

TCDe-energizes(See Note)

TCEnergizes

(See Note)

FALLINGTEMPERATURE

RISINGTEMPERATURE

---1.5_C (---2.7_F)

---1_C (---1.8_F)

---0.5_C (---0.9_F)

---0.25_C

0.25_C

1.5_C (2.7_F)

1_C (1.8_F)

0.5_C (0.9_F)

NOTE

2_C (3.6_F)

---2_C (---3.6_F)

AIRCIRCULATIONONLY

IRSEnergizes

IRSDe-energizes

IRSEnergizes

IRSDe-energizes

TCEnergizes(See Note)

TCDe-energizes(See Note)

(See Note)

(See Note)

TH Energizes(See Note)

Switchingfunctionsareaffected bytime delays. (Refer to paragraph 1.17.k.)

Figure1-9.Controller Set Point Below---10_C (14_F) --- Return Air Control

Figure1-10. Controller Set Point Above ---10_C (14_F) --- SupplyAir Control

TH De-energizes

In-Range

In-Range

In-Range In-Range

AIRCIRCULATIONONLY

SET POINT

5/22/2018 T252 - 69 NT20-284 69NT40-461-464

23/120

2-1

SECTION 2

OPERATION

2.1 PRE-TRIP INSPECTION (BeforeStarting)

WARNING

Beware of unannounced starting of theevaporator andcondenser fan.

a. If container is empty, check insidefor the following:

1. Check channels or T bars on floor forcleanliness. Channels must be free of debris for properair circulation.

2. Check container panels, insulation and doorseals for damage. Effect permanent or temporaryrepairs.

3. Visually check evaporator fan motor mountingbolts for proper securement.

4. Check for dirtor greaseon evaporatorfanor fandeck and clean if necessary.

5. Check evaporator coil for cleanliness orobstructions. Wash with fresh water. (Refer to section 4.13)

6. Check defrost drain pans and drain lines forobstructions and clear if necessary. Wash with freshwater.

7. Check panels on refrigeration unit for loosebolts and condition of panels. M ake sure T.I.R. devicesarein place on access panels.

b. Check condenser coil for cleanliness. Wash withfresh water. (Refer to section 4.17)

c. Check position of fresh air makeup vent cover.Operator must determine if fresh air makeup vent coveris to be opened or closed.

d. Open Partlow recording thermometer (if soequipped) door and do thefollowing:

1. Manually wind clock on recordingthermometer(keyislocatedin aclip.) K EY MUST STAY WIT H TH ETH ER MOM ET ER .

2. Lift stylus(pen) bypushingdownthestyluslifterand rotating the lifter clockwise (raising stylus at sametime) until lifter locks in position.

3. Install new chart on recording thermometermakingsurechart is under thefour corner tabs. Releasestylus lifter by pushing down and rotating liftercounterclockwise until stylus lifter locks in position and

stylus has made contact with chart. Then secure door.e. Open Saginomiya recording thermometer (if soequipped) door and do thefollowing:

1. Check Chart drive battery condition. (Refer tosection 4.20)

2. Lift stylus (pen) by pushing in the stylus lifterand rotating the lifter clockwise (raising stylus at sametime) until lifter locks in position.

3. Install new chart on recording thermometermakingsurechart is under thefour corner tabs. Releasestylus lifter by pushing down and rotating lifter

counterclockwise until stylus lifter locks in positionstylus has made contact with chart. Then secure doo

f. Open Fuji Kiki recording thermometer (ifequipped) door and do thefollowing:

1. Check Chart drive battery condition. (Refesection 4.21)

2. Lift stylus (pen) by pushing in the stylus liand rotating the lifter clockwise (raising stylus at stime) until lifter locks in position.

3. Install new chart on recording thermommakingsurechart is under thefour corner tabs. Relestylus lifter by pushing down and rotating licounterclockwise until stylus lifter locks in positionstylus has made contact with chart. Then secure doo

g. Open the control/contactor box door. Check looseelectrical connectionsor hardware.

h. Check color of moisture-liquid indicator.

i. Check oil level in compressor sight glass.

j. Check quench valve operation.

k. Check modulation valve coil resistance. (Refesection 4.25)

l. Start refrigeration unit. (Refer to section 2.3)

2.2 STARTING AND STOPPING INSTRUCTION

CAUTION

Makesurethattheunitcircuit breaker(S) (CB)andthestart-stopswitchareintheOFFpositionbeforeconnectingtoanyelectricalpower source.

p. StartingtheUnit

1. Refer to Pre-Trip Inspection, section 2.1.

2. Makesureunit circuit breaker(s) andstart-switch are in position O (OFF position).

3. Check power sourcefor proper voltage.Conunit power plugand turn main power ON.

4. Turn refrigeration unit circuit breaker(s),

thestart-stop switch ON (position 1).

5. To adjust the temperature set points, depSDS switch and turn temperature selector knob wlooking at the digital temperature display. Tprocedureallowstemperaturesettingswithin atenthdegree centigrade.

6. Refer to section 2.3after unit is running.

q. StoppingtheUnit

Turn the start-stop switch to position O (OFF).

5/22/2018 T252 - 69 NT20-284 69NT40-461-464

24/120

2-2

2.3 AFTER STARTING INSPECTION

a. Check rotation of condenser and evaporator fans.

b. Check compressor oil level.

c. Check operation --- determine if unit respondsproperlyto settingof controller,cyclingfromheattocool,at controller setting.

d. Feel filter-drier. Excessive temperature drop acrossdrier indicates restriction.

2.4 UNIT OPERATION

2.4.1 Cooling --- Controller Set Below---10_C (14_F)

Ondecreasingreturnair temperaturetheunit will bein coolingwith thecondenser fan motor and evaporatorfan motors energized. With set points below ---10_C(14_F), theevaporator fanmotorswill be in lowspeedasrelayTU is de-energized (contactor ES energizes).

If thecontainer returnair iswithin2_C (3.6_F) ofsetpoint, the in-range relay contacts (IRS) are closed andthe in-range light (I RL) is illuminated.

When the return air temperature decreases to0.25_C (0.5_F) below set point, a timing function

commences which delays de-energizing of relayTC andresultingin de-energizingthecompressor andcondenserfan motor. Also, the cool light is de-energized. Theevaporator fan motors continue to run to circulate airthroughout the container.

NOTES

1. When thereturn air temperaturedecreasesto ---12.2_C (10_F) on the Model 69NT40units,the suction solenoid thermostat closes toenergize the suction solenoid valve. The valveopens to increase the refrigerant flow rate andcoolingcapacity.

2. In the frozen range the suction modulationis limited to approximately0.4amp or valveis25percent closed.

3. The quench valve will not be energized atthistimeasthesuction modulation valvecurrentwill not reach 0.6 amp (necessary to energizequench valve).

4. Somemodelshaveathermostaticexpansionquench valve (refer to section 5).

5. Setting the controller below ---10_C (14_F)on units with two-speed motors will place the

motorsin low speed (contactor ES energizes).When the return air temperature increases to 0.25_C

(0.5_F) above set point, and providing a sufficient off

period has elapsed, relay TC energizes to restart thecompressor. Also, at this time, the condenser fan motorstartsand the cool light is illuminated.

2.4.2 Controller Set Above ---10_C (14_F)

a. Cooling(SeeFigure2-1)

With decreasing supply air temperature and if thesupply air is morethan 2_C (3.6_F) above set point, theunit will be cooling with the condenser fan motor,compressor motor and evaporator fan motorsenergized.The evaporator fan motors will be in high speed as relayTU is energized (contactor ES de-energizes andcontactor EF energizes).

Also, at this time, the cool light is illuminated. Thein-range light is de-energized.

When theair temperaturedecreases to 2_C (3.6_F)aboveset pointrelayIRSenergizesandthein-rangelightis illuminated.

If the air temperature continues to fall, modulatingcoolingstartsatapproximately0.25_C (0.45_F) abovesetpoint. The modulatingvalve will have a variablecurrent

up to 1.45 ampsat full modulation.At this time, it is possible for the quench valve to

energize before the compressor shuts off as the valveenergizes with a minimumamp draw of 0.6. Thequenchvalve will de-energize if the amp draw falls below 0.55amp.

NOTE

Some Models have a thermostatic expansionquench valve (refer to section 5).

When the supply air temperature decreases to 0.25_C(0.5_F) below set point, a timing function commences

which delays de-energizing of relay TC resulting inde-energizing the compressor and condenser fan motor.Also, the cool light is de-energized.

The evaporator fan motors continue to run to circulateair throughout the container. The in-range light remainsilluminated as longas the return air is within 2_C (3.6_F) ofset point.

If the unit is in the holding mode (neither heating orcooling) and the supply air temperature increasesto 0.25_C(0.5_F) above set point, and providing a sufficient off timehas elapsed, relay TC energizes to restart the compressor.Also, at this time, the condenser fan motor starts and thecool light is illuminated.

When thesupply air temperature increases2_C (3.6_F)above set point, relay IRS and the in-range light is off. Thecool light remainsenergized.

5/22/2018 T252 - 69 NT20-284 69NT40-461-464

25/120

2-3

TO CONTROL TRANSFORMER

= Energized Circuit = De-energized Circuit

Figure2-1. Cooling --- Within 2_C (3.6_F) of Set Point

5/22/2018 T252 - 69 NT20-284 69NT40-461-464

26/120

2-4

TO CONTROL TRANSFORMER

= E nergized Circuit = D e-energized C ircuit

Figure2-2. Heating--- Within 2_C (3.6_F) of Set Point

b. Heating (SeeFigure2-2)

The unit will only heat when the controller is setabove ---10_C (14_F) asrelayTH is electronicallylockedout to prevent heating when the controller is set below---10_C (14_F).

If the supply air temperature decreases 1.0_C

(1.8_F) below controller set point T H closes and thesystementersthe heatingmodewhichis designedtoraisethe container air temperature. When TH closes, powerflows through the TC contacts T9 and T8, TH contacts,the heat termination thermostat to energize the heatrelay (HR ). This in turn energizes the heaters and heatlight. Theevaporator fans continue to runin high speedto circulate air throughout thecontainer.

Asthe supplyair decreasesto 2_C (3.6_F) belowsetpoint, relayI RS andthein-rangelight de-energize(after90minutestimedelay) andwill remainde-energizeduntilthe supplyair increases to 2_C (3.6_F) belowset point.

When thetemperaturerises to 0.5_C (0.9_F) belowset point, TH opens (heatingoff) and the system againentersthe holdingzone. Thecompressor and condenserfanmotor arenotrunningascontactorsC and CF remainde-energized. The evaporator fans continue to run inhigh speed to circulateair throughout thecontainer.

A safety heater termination thermostat (HTT)attached to an evaporator coil support, set to open at54.5_C (130_F) will open the heating circuit ifoverheatingoccurs.

5/22/2018 T252 - 69 NT20-284 69NT40-461-464

27/120

2-5

2.4.3 Defrost (SeeFigure2-3)

Refer to paragraph 1.16.f for description of thedefrostinterval selectorandautomaticdefrostinitiation.

When the defrost mode is initiated, the controllerrelaycontacts(TH, T11to T10) close to supplypower totheheat relay and in turn energizes thedefrost heaters.

Also, at the same time, the defrost relay contacts(T19 to T20) close to illuminate the defrost light.

Energizingthedefrost relayalso opensthenormally

closed contacts (T19 to T18) to stop the evaporator fanmotors.

TC (T9 toT31) openstode-energizethecomprecontactor, cool light, and the condenser fan mcontactor.

The in-range light remains illuminated dudefrost. (Refer to paragraph 1.16.g)

When the coil temperature reaches 24_C (75defrost termination thermostat opens to interrupt defrost cycle andthe unit returnsto its normal funct

The 54.5_C (130_F) heat termination thermowill open the circuit if the defrost mode does terminate at 24_C (75_F).

TO CONTROL TRANSFORMER

= E nergized C ircuit = D e-energized C ircuit

Figure2-3.Defrost

5/22/2018 T252 - 69 NT20-284 69NT40-461-464

28/120

2-6

Table2-1. Electrical Control Positions --- Above ---10_C (14_F)

CONTROL CIRCUIT COOLING HOLDINGZONE

* Dehumidifica-tion

HEATING DEFROST

Compressor Contactor(C)

Energized De-energized Energized De-energized De-energized

Condenser FanMotorContactor (CF)

Energized De-energized Energized De-energized De-energized

OneSpeed Evaporator

Motor Relay (EF)

Energized Energized Energized Energized De-energized

TwoSpeedEvaporatorMotor Relay (EF)

Energizedat set pointsabove --10_C (14_F) De-energized

TwoSpeedEvaporatorMotor Relay (ES)

De-energized atset pointsabove --10_C (14_F)

Defrost Relay (DR) De-energized De-energized De-energized De-energized Energized

Heater Relay (HR) De-energized De-energized Energized Energized Energized

QuenchSolenoid (QV) Refer topara-graph1.16.c

De-energized Refer to para-graph1.16.c

De-energized De-energized

CONTROLLER RELAYS

DR (Defrost) OFF OFF OFF OFF ON

IRS (In-Range) Closed -- If supply air iswithin 2_C (3.6_F) of set point

TC (Cooling) ON OFF ON OFF OFFTH (Heating) OFF OFF ON ON ON

TQ (Quench) Refer to N/A N/A N/A N/A

TU (Utility) paragraph 1.16.c

(Two-Speed Motors) Energized withcontroller settings above --10_C (14_F)

INDICATING LIGHTS

Cool ON OFF ON OFF OFF

Defrost OFF OFF OFF OFF ON

In-Range On-- If supply airiswithin2_C (3.5_F) of set point

Heat OFF OFF ON ON ON

POWER CIRCUIT

Compressor Energized De-energized Energized De-energized De-energized

Condenser Fan Motor Energized De-energized Energized De-energized De-energized

Heaters De-energized De-energized Energized Energized Energized

Evaporator Fan Motors Energized Energized Energized Energized De-energized

* Unit withoptional Humidistat (Refer to section 1.7)

N/A -- NotApplicable

5/22/2018 T252 - 69 NT20-284 69NT40-461-464

29/120

2-7

Table2-2. Electrical Control Positions --- Below---10_C (14_F)

CONTROL CIRCUIT COOLING HOLDINGZONE

**Dehumidifica-tion

HEATING DEFROST

Compressor Contactor(C)

Energized De-energized ** ** De-energize

Condenser FanMotorContactor (CF)

Energized De-energized ** ** De-energize

OneSpeedEvaporator

Motor Relay (EF)

Energized Energized ** ** De-energize

TwoSpeed EvaporatorMotor Relay (EF)

De-energizedat set points below --10_C (14_F)

TwoSpeed EvaporatorMotor Relay(ES)

Energizedat set points below --10_C (14_F) De-energize

Defrost Relay (DR) De-energized De-energized ** ** Energized

Heater Relay (HR) De-energized De-energized ** ** Energized

QuenchSolenoid(QV) Refer toparagraph 1.16.c

De-energized ** ** De-energize

CONTROLLER RELAYS

DR (Defrost) OFF OFF ** ** ON

IRS (In-Range) Closed -- If supply air iswithin2_C (3.6_F) of set point

TC (Cooling) ON OFF ** ** OFFTH (Heating) OFF OFF ** ** ON

TQ (Quench) Refer to N/A ** ** N/A

TU (Utility) paragraph 1.16.c

(Two-Speed Motors) Energizedwithcontroller settings below --10_C (14_F)

INDICATING LIGHTS

Cool ON OFF ** ** OFF

Defrost OFF OFF ** ** ON

In-Range On -- If supply air iswithin2_C (3.5_F) of set point

Heat OFF OFF ** ** ON

POWER CIRCUIT

Compressor Energized De-energized ** ** De-energize

Condenser Fan Motor Energized De-energized ** ** De-energize

Heaters De-energized De-energized ** ** Energized

Evaporator Fan Motors Energized Energized ** ** De-energize

** Dehumidification andheatingmodes donot operateat set pointsbelow --10_C (14_F)

N/A -- Not Applicable

5/22/2018 T252 - 69 NT20-284 69NT40-461-464

30/120

3-1

SECTION 3

TROUBLESHOOTING

INDICATION/ POSSIBLE CAUSES REFERENC

TROUBLE SECTION

3.1 UNIT WILL NOT START OR STARTS THEN STOPS

No power to unit External power source OFF Turn onStart-Stop switch O FF or defective CheckCircuit breaker tripped or OFF Check

L oss of control power Circuit breaker OFF or defective CheckControl transformer defective (T R) ReplaceFuse blown (3A or 6A) CheckStart-Stop switch O FF or defective CheckEvaporator fan motor internal protector open 4.14Condenser fan motor internal protector open 4.18Compressor internal protector open 4.5High pressure switch open 4.11

Compressor hums, L ow line voltage Checkbut does not start Single phasing Check

Shorted or grounded motor windings 4.5Compressor seized 4.5

3.2 UNIT RUNSBUT HAS INSUFFICIENT COOLING

Compressor Compressor valves defective 4.5

Refrigeration System Abnormal pressures 3.7Temperature controller malfunction 3.9Evaporator fan or motor defective 4.14Modulatingsolenoidvalvemalfunction 4.25Suction solenoid valve malfunction 1.14

3.3 UNIT OPERATESLONG OR CONTINUOUSLY IN COOLING

Container Hot load NormalDefective box insulation or air leak Repair

Refrigeration System Shortage of refrigerant 4.2/4.4Evaporator coil covered with ice 3.6E vaporator coil plugged with debris 4.13Evaporator fan(s) rotatingbackwards 4.14/4.28Defective evaporator fan motor/capacitor 4.14/4.28A ir bypass around evaporator coil CheckController set too low ResetCompressor servicevalvesor liquid Open valvesline shutoff valve partiallyclosed completely

Dirty condenser 4.17 or 4.23Compressor worn 4.5

5/22/2018 T252 - 69 NT20-284 69NT40-461-464

31/120

3-2

INDICATION/ POSSIBLE CAUSES REFERENCE

TROUBLE SECTION

3.4 UNIT WILL NOT HEAT OR HAS INSUFFICIENT HEATING

No power to unit Start-Stop switch OFF or defective CheckCircuit breaker OFF or defective CheckExternal power source OFF Turn on

No control power Circuit breaker or fuse defective ReplaceTransformer defective (TR ) ReplaceCondenser fan internal motor protector open 4.18Evaporator fan internal motor protector open 4.14Heat relay defective Check

Heater termination switch open 4.13

Unit will not heat or Heater(s) defective 4.15has insufficient heat H eater contactor or coil defective Replace

Evaporator fan motor(s) defective or rotatingbackwards 4.14/4.28Evaporator fan motor contactor defective ReplaceTemperature controller malfunction 3.9

Defective wiring ReplaceL oose terminal connections TightenL ow line voltage 1.5

3.5 UNIT WILL NOT TERMINATE HEATING

Unit failsto stop heating Temperaturecontroller improperlyset ResetTemperature controller malfunction 3.9Heater termination switch remainsclosed along with the heat relay 4.13

3.6 UNIT WILL NOT DEFROST PROPERLY

Will not initiate Defrost timer malfunction 1.16.f defrost automatically L oose terminal connections Tighten

Defective wiring ReplaceDefrost termination or heat termination switch open 4.13H eater contactor or coil defective Replace

Will not initiate Manual defrost switch defective Replacedefrost manually Defrost termination switch open 2.4.3

Initiates but defrost relay(DR) drops out L ow line voltage 1.6

Initiatesbut doesnot defrost Heater contactor or coil defective ReplaceHeater(s) burned out 4.15

Frequent defrost Wet load Normal

5/22/2018 T252 - 69 NT20-284 69NT40-461-464

32/120

3-3

INDICATION/ POSSIBLE CAUSES REFERENC

TROUBLE SECTION

3.7 ABNORMAL PRESSURES (COOLING)

High discharge pressure Condenser coil dirty 4.17 or 4.23Condenser fan rotating backwards 4.18Condenser fan inoperative 4.18

Refrigerant overcharge or noncondensibles 4.4Quench solenoid valve malfunction 4.12

L ow suction pressure Suction service valve partially closed OpenFilter-drier partially plugged 4.10L ow refrigerant charge 4.2/4.4Expansion valve defective 4.27No evaporator air flowor restricted air flow 3.10Excessive frost on evaporator coil 3.6Evaporator fan(s) rotatingbackwards 4.14/4.28

3.8 ABNORMAL NOISE OR VIBRATIONS

Compressor L oose mounting bolts TightenWorn bearings 4.5

Worn or broken valves 4.5Liquid slugging 3.11Insufficient oil 4.8

Condenser or Bent, loose or strikingventuri CheckEvaporator Fan Worn motor bearings 4.14/4.18

Bent motor shaft 4.14/4.18

3.9 TEMPERATURE CONTROLLER MALFUNCTION

Will not control or relay(s) Controller relay(s) defective 4.26do not actuate at Defective Sensor 4.26.6proper temperature Defective wiring 4.26

Controller malfunction 4.26

Compressor does not startor stop at specified temperature Timedelayperiod not elapsed 1.16.d

3.10 NO EVAPORATOR AIR FLOWOR RESTRICTED AIR FLOW

Evaporator coil blocked Frost on coil 3.6Dirty coil 4.13

No or partial E vaporator fan motor internal protector open 4.14evaporator air flow E vaporator fan motor(s) defective 4.14/4.28

E vaporator fan(s) loose or defective 4.14

5/22/2018 T252 - 69 NT20-284 69NT40-461-464

33/120

3-4

INDICATION/ POSSIBLE CAUSES REFERENCE

TROUBLE SECTION

3.11 EXPANSION VALVE MALFUNCTION

L ow suction pressure L ow refrigerant charge 4.2/4.4with high superheat External equalizer line plugged Open

Wax, oil or dirt pluggingvalve or orifice 4.27

Ice formation at valve seat 4.2/4.3Superheat too high 4.27.cPower assembly failure 4.27L oss of element/bulb charge 4.27Broken capillary 4.27Foreign material in valve 4.27

High suction pressure Superheat setting too low 4.27.cwith low superheat External equalizer line plugged Open

Ice holding valve open 4.2/4.3Foreign material in valve 4.27

Liquid sluggingin compressor Pin and seat of expansion valve eroded orheld open by foreign material 4.27

Fluctuatingsuction pressure Improper bulb location or installation 4.27L ow superheat setting 4.27.c

3.12 WATER-COOLED CONDENSER OR WATER PRESSURE SWITCH MALFUNCTION

High discharge pressure Dirty coil 4.23Noncondensibles 4.23

Condenser fan Water pressure switch malfunction Checkstarts and stops Water supply interruption Check

3.13 STEP-UPPOWER TRANSFORMER MALFUNCTION

Unit will not start Circuit breaker (CB2) tripped CheckStep-up transformer internal protector open 4.24Step-up transformer defective 4.24Power source not turned ON Check

5/22/2018 T252 - 69 NT20-284 69NT40-461-464

34/120

4-1

SECTION 4

SERVICE

4.1 REMOVING THE REFRIGERANT

NOTE

To avoid damage to the earthsozone layer,use a refrigerant recovery systemwheneverremovingrefrigerant.

To Service any High and L ow Side Refrigeration Component:

Store the refrig