Thermo King 914 724 Manual Download Page 59

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Refrigeration Maintenance (Rev. 1/99)

REFRIGERANT HOSE ROUTING

To prevent oil trapping, the suction hose must be clamped in

a U trap before it goes to the compressor

Correct Hose Routing

Incorrect Hose Routing

(Will Cause Oil Trapping)

To Condenser

Under Cab

To Compressor

Vertical Lift

Form A “U” Trap

AGA294

Summary of Contents for 914 724

Page 2: ...ourse of dealing or usage of trade are made regarding the information recommendations and descriptions contained herein Manufacturer is not responsible and will not be held liable in contract or in to...

Page 3: ...ontact your local THERMO KING dealer R 404A and R 134a CAUTION Use ONLY Polyol Ester based refrigeration compressor oil TK P N 203 413 in R 404A and R 134a units DO NOT use Polyol Ester based oil in s...

Page 4: ......

Page 5: ...the Unit 25 Adjusting the Thermostat 26 After Start Inspection 26 Loading Procedure 27 Post Loading Procedure 27 Weekly Post Trip Checks 27 Electrical Maintenance 29 Unit Wiring 29 Remote Control Box...

Page 6: ...Hoses 55 Liquid Injection Solenoid Valve 56 Liquid Injection Metering Orifice 56 Testing the Liquid Injection Solenoid Valve and Metering Orifice 57 High Pressure Cutout And Condenser Fan Switches 57...

Page 7: ...emoval and Installation 71 Special Tools 74 System Compressor and Oil 76 Checking the Oil Level 77 Electrical Connection 77 Clutch Test 78 Belt Tensions 78 Engine Compressor Belt and Pulleys 78 Over t...

Page 8: ......

Page 9: ...Refrigerant tends to displace air and can cause oxygen depletion resulting in suffocation and possible death 11 In the USA EPA Section 608 Certification is needed to work on refrigeration systems REF...

Page 10: ...ilable The source of shock must be immediately removed by either shutting down the power or removing the victim from the source If it is not possible to shut off the power the wire should be cut with...

Page 11: ...o 48 kPa Condenser Pressure Fan Switch Opens 130 10 psi 896 69 kPa Closes 180 10 psi 1241 69 kPa Suction Pressure Regulator Setting 18 psi 124 kPa Defrost Timer Initiation Interval 4 hours Termination...

Page 12: ...12 Vdc 0 17 0 12 1850 to 2250 8 0 to 14 5 amps 24 Vdc 0 1 0 12 1850 to 2250 4 2 to 7 8 amps Pilot Solenoid and Liquid Injection Solenoid Coils Voltage Current Resistance 12 Vdc 0 6 to 0 8 amps 15 to...

Page 13: ...onal Electric Heaters Voltage Power Rating Watts Current Resistance 230 Vac 800 3 48 amps 66 1 ohms 380 Vac 800 2 1 amps 180 5 ohms BELT TENSION Using Tool P N 204 427 Field Reset Engine Compressor 35...

Page 14: ...4...

Page 15: ...ts Check thermostat and thermometer calibration in 32 F 0 C ice water bath Inspect wire harness for damaged wires or connections Inspect replace dc fan motor brushes yearly REFRIGERATION Check refrige...

Page 16: ...6...

Page 17: ...the electric standby cord is still plugged into the power receptacle The electric standby compressor is connected in parallel with the engine driven compressor on the Model 20 units The engine compres...

Page 18: ...the condenser and evaporator fans The condenser fan is also controlled by the condenser fan pressure switch This normally open switch monitors the compressor discharge pressure When the discharge pres...

Page 19: ...which terminates the defrost cycle If the defrost termination switch does not open in less than 45 minutes the defrost timer will terminate the defrost cycle 45 minutes after is was started OPERATING...

Page 20: ...ant High Pressure Cutout Refrigerant Low Pressure Cutout Refrigerant High Pressure Relief Valve Power Cord Warning Light in Optional Cab Control Box for Model 20 only Overload Relay Protection for Ele...

Page 21: ...Unit Description Rev 1 99 11 Front Roadside View 1 Electric Motor Reset Model 20 Only 2 Master On Off Switch 3 Control Box Cover Front Curbside View 1 2 3 AGA321 AGA320...

Page 22: ...it Description Rev 1 99 12 1 Receiver Outlet Valve 5 Sight Glass 2 Accumulator 6 Condenser Check Valve 3 Drier 7 High Pressure Valve 4 Liquid Injection Solenoid Roadside Components 5 6 4 7 1 2 3 AGA41...

Page 23: ...13 1 Defrost Timer 6 Fan Relay 2 Defrost Relay 7 Cool Relay 3 Circuit Breakers 8 Heat Relay 4 Terminal Board 9 Power Disconnect Relay 5 Defrost Jumper Emergency Use Only Model 10 Control Box Component...

Page 24: ...on Rev 1 99 14 1 Defrost Timer 5 Terminal Board 2 Defrost Relay 6 Motor Contactor 3 Circuit Breakers 7 Overload Relay 4 Fan Relay 8 3 Phase Transformer Model 20 3 Phase Control Box Components AGA336 8...

Page 25: ...Unit Description Rev 1 99 15 1 Fan 2 Thermometer Sensor 3 Thermostat Sensor Evaporator 1 2 3 AGA358...

Page 26: ...ion Rev 1 99 16 1 ORS Fittings 5 Thermostat Sensor 2 Heat Exchanger 6 Thermometer Sensor 3 Expansion Valve 7 Evaporator Coil 4 Defrost Termination Switch 8 Pan Heater Evaporator Components 8 7 6 5 4 A...

Page 27: ...1 99 17 1 Defrost Termination Switch 5 Heat Exchanger 2 Expansion Valve 6 Thermostat Sensor 3 Fan Motor Two Used 7 Pan Heater 4 ORS Fittings 8 Evaporator Coil Exploded View of CBci MAX Evaporator 6 5...

Page 28: ...Unit Description Rev 1 99 18 1 On Light 4 Manual Defrost Switch 2 On Off Switch 5 Defrost Light 3 Wing Screw 6 Thermometer Remote Control Box 1 2 3 6 5 4 AGA416...

Page 29: ...Unit Description Rev 1 99 19 1 Cool Light 5 Inner Dial 2 Heat LED 6 Thermostat Module 3 Thermostat Dial 7 On LED 4 Outer Bezel Inside Remote Control Box AGA292 1 2 3 4 5 6 7...

Page 30: ...Overload Relay 2 Defrost Relay 8 Chokes 3 Circuit Breakers 9 Clutch Relay 4 Fan Relay 10 Fuse 5 Terminal Board 11 Standby Relay 6 Motor Contractor 12 Single Phase Transformer Model 20 Single Phase Con...

Page 31: ...21 1 LED Display 6 Manual Defrost Switch 2 Setpoint LED 7 On Off Switch 3 Power Cord LED Model 20 Only 8 Setpoint Switch 4 On LED 9 Thermostat Dial 5 Defrost LED Cab Control Box Standard on New Units...

Page 32: ...22...

Page 33: ...t switch must be pushed to display the thermostat setpoint 2 SETPOINT SWITCH Pushing this switch displays the thermostat setpoint on the LED display and causes the setpoint LED to light up 3 ON OFF SW...

Page 34: ...CTION DEVICES 1 CONTROL SYSTEM CIRCUIT BREAKERS The control system circuit breaker is located in the unit con trol box It trips if the control circuit is overloaded Model 20 units have a second contro...

Page 35: ...pleted before loading the truck While the weekly inspection is not a substitute for regularly scheduled maintenance inspections it is an important part of the preventive mainte nance program designed...

Page 36: ...ears on the LED display while the unit is turned on Pressing the setpoint switch lights the setpoint LED and causes the thermostat setpoint to appear on the LED display To check or change the thermost...

Page 37: ...oducts should be precooled before loading Thermo King units are designed to maintain loads at the temperature at which they are loaded Transport refrigeration units are not designed to pull hot loads...

Page 38: ...28...

Page 39: ...t terminal and the CH circuit terminal on the back of the ther mometer Battery voltage 12 or 24 volts should be present 5 If battery voltage is not present check a The wiring connectors and components...

Page 40: ...Thermometer Before replacing the thermometer make sure that another problem such as a loose wire connection or a bad ground is not causing the thermometer to malfunction Thermometer Calibration Test...

Page 41: ...wires 3 pin connector 4 Disconnect the thermostat sensor harness from the ther mostat wires SN4 SN5 and SN6 from terminals T11 T10 and T9 respectively 5 Connect the thermostat sensor harness wires to...

Page 42: ...he thermometer reading 1 F 0 6 C the unit should shift to null The Heat LED should go out and the Cool LED should not be lit The cool relay and the heat relay should both be de energized 5 Continue to...

Page 43: ...omponents 1 3 4 2 AGA295 3 Use a known good thermometer or a 32 F 0 C ice water bath to check the switch points The unit should shift from cool to null at 32 F 0 C 4 If the unit shifts modes properly...

Page 44: ...on the LED display This is the tem perature display a Normal display 40 to 199 F 40 to 93 C TCM Display Diagnosis Chart Setpoint Display Normal Display Blank Display Erratic Display No Change Tempera...

Page 45: ...k the wiring and con nectors in the SN1 SN2 and SN3 circuits back to the cab control box If there are no faults in the SN1 SN2 and SN3 circuits repeat the Initial TCM Display Test If the results of th...

Page 46: ...t defective before assuming that the TCM is faulty Specifically 1 Battery voltage must be present on wire CR1 pin 5 and wire HR1 pin 7 in the 14 pin connector on the cab control box wire harness when...

Page 47: ...r in the defrost timer socket slots 1 2 and 3 Pressing the Manual Defrost switch should then cause the unit to shift to defrost until the defrost termination switch opens Manual Defrost Switch A Manua...

Page 48: ...noid coil is energized it lifts the pilot solenoid valve piston and allows refrigerant pressure to shift the three way valve This routes hot refrigerant gas to the evap orator Testing the Defrost Syst...

Page 49: ...utes after it is initiated Unit Sticks in Defrost Indefinitely 1 Check the defrost timer If the unit has been stuck in defrost for more than 45 minutes remove the defrost timer from its socket If the...

Page 50: ...opened 1 Test Terminal Defrost Timer 1 AEA502 Temporary Defrost Timer Bypass Procedure If the timer fails and a replacement is not available bypass ing the timer will allow the manual defrost switch...

Page 51: ...iate for another brief period of time This On Off cycle should repeat until the 12 circuit opens 5 If the defrost timer fails to function properly replace the defrost timer Defrost Timer Bench Test Th...

Page 52: ...eration If CBI opens check the unit for a grounded wire a defec tive solenoid a defective relay or a defective fan motor CONDENSER FAN PRESSURE SWITCH CFPS The CFPS is located in the discharge line El...

Page 53: ...line voltage is accept able and the transformer fuses are intact go to step 2 2 Measure the transformer output voltage AC at the ter minal board Measure the voltage between wires A and B between wire...

Page 54: ...nstalled correctly the rectifier is defec tive If the rectifier output voltage is more than 14 Vdc the choke is defective 24 Volt System Single Phase Electric Standby The DC voltage should be 24 to 30...

Page 55: ...repair the leak 6 After the additional hour of evacuation close the valve at the evacuation pump stop the vacuum pump and observe the reading on the vacuum gauge for 5 min utes The pressure should no...

Page 56: ...o not operate the compressor for shorter inter vals Checking the Refrigerant Charge If the unit has an insufficient charge of refrigerant the evap orator will be starved and the box temperature will r...

Page 57: ...hours or until the compressor oil level reaches a minimum allowable level whichever occurs first Drain the col lected oil from the oil separator as it fills taking care to not allow any collected oil...

Page 58: ...ch as a TK 214 model Connect an oil separator on the discharge or suction line to collect and drain out circulated oil NOTE A suction line oil separator can be improvised by installing a suction filte...

Page 59: ...prevent oil trapping the suction hose must be clamped in a U trap before it goes to the compressor Correct Hose Routing Incorrect Hose Routing Will Cause Oil Trapping 1 To Condenser 2 Under Cab 3 To...

Page 60: ...nifold set on the compressor 4 Close front seat the receiver tank outlet valve 5 Operate the unit in cool and pump down the low side to 20 in Hg of vacuum 68 kPa 6 Stop the unit The condenser and suct...

Page 61: ...s tem 1 Place the compressor in position and install the mount ing screws and the belt 2 Use belt tension tool P N 204 427 to adjust belt ten sion The engine compressor belt tension should be adjusted...

Page 62: ...e housing 2 Install the mounting bolts and tighten them 3 Clean the tubes for soldering 4 Solder the suction line to the evaporator coil 5 Connect the hot gas line to the distributor 6 Connect the exp...

Page 63: ...5 Recharge the unit OIL SEPARATOR Once installed the oil separator unit requires no mainte nance However all connections to the separator and throughout the refrigeration system should be checked on...

Page 64: ...example of the installa tion NOTES 1 When using flare fittings lubricate the mating surfaces as well as the flare fitting threads prior to connecting 2 Use tubing wrenches to tighten all connections...

Page 65: ...41 AGA342 b Lubricate nipple threads and inside of hose with refrigerant oil Refrigerant Hose Installation 1 Apply clean compressor oil to the flares to facilitate the connection and use two wrenches...

Page 66: ...enoid valve to the mounting bracket 2 Connect refrigerant lines to both sides of the solenoid valve The line from the liquid line is connected to the port marked IN 3 Connect the coil wires to the sol...

Page 67: ...llation 1 Apply a refrigerant locktite to the threads of the switch 2 Install and tighten the switch and reconnect the wires 3 Pressurize the refrigeration system and test for leaks 4 If no leaks are...

Page 68: ...is increasing or has increased noticeably the discharge check valve is leaking internally 7 Turn the unit off and shut off the truck engine Connect the remote control box to an appropriate electric p...

Page 69: ...surfaces Replace the pistons if the sealing surfaces are worn or damaged 8 Inspect the valve body The piston bores should be clean and undamaged The pistons should move freely in the piston bores Cle...

Page 70: ...he copper sealing washer should face the valve body and the smooth side should face the end cap 7 Carefully place the end cap in the valve body to avoid damaging the piston copper sealing washer or th...

Page 71: ...support area b Seat sealing surface c Top cap sealing and support area Remove the screen If any particles drop from the screen into the discharge line the discharge line must be removed at the compre...

Page 72: ...Remove the snap ring 4 Unscrew the check valve stem by using a screwdriver in the slot provided NOTE The spring and the check valve are held in by the stem While removing the stem use care to make su...

Page 73: ...down the low side and equalize the pressure to slightly positive 2 Disconnect the coil wires 3 Disconnect the refrigeration lines to the solenoid and immediately seal them to prevent moisture and air...

Page 74: ...frigerant and check the compressor oil O Ring Seal ORS Connections Replacement 1 Close the receiver outlet valve pump down the low side and equalize the pressure to slightly positive 2 To break the th...

Page 75: ...wing compressed air down through the coil out into the box direction opposite the normal air flow Inspect the coil and fins for damage and repair if nec essary requires removing the evaporator fan and...

Page 76: ...tions by blowing compressed air from the back side of the coil out toward the front of the unit the direction opposite normal air flow Inspect the coil and fins for dam age and repair if necessary UNI...

Page 77: ...inst the pulley web and compresses the flat springs This causes the hub and disk to rotate with the pulley Compressor Clutch Assembly CLUTCH REMOVAL NOTE Make sure the proper tools are available befor...

Page 78: ...ng the clutch remover TK No 204 806 and the spacer positioned on the cylinder head hub 1 Snap Ring 2 Cover NOTE To avoid damaging the pulley groove the pulley claws should be hooked into NOT UNDER the...

Page 79: ...plate 3 Coil Inspect the coil for a loose connector or cracked insula tion If the insulation is cracked replace the coil Repair or replace the wire or the connector if either is loose or damaged Clut...

Page 80: ...ers NOTE When installing the snap ring the chamferred inner edge of the snap ring should face upward Install Cover and Snap Ring 6 Install the driver plate on the drive shaft together with the origina...

Page 81: ...0 0197 in 0 5 mm 1 Shims NOTE Specified clearance 0 01 to 0 02 in 0 3 to 0 6 mm Check Clearance Electrical Connection 1 Connect the lead wire to the electrical circuit NOTE The stationary field is gro...

Page 82: ...4 Use the seal remover from the shaft seal kit P N 204 805 to remove the shaft seal Turn the seal remover to engage the hook on the seal remover with the hook on the shaft seal then slowly pull the sh...

Page 83: ...es and apply clean compressor oil 3 Place the seal guide from the shaft seal kit P N 204 805 on the end of the shaft Place Guide on Shaft 1 Seal Guide 4 Place the shaft seal on the seal guide and slid...

Page 84: ...l kit P N 204 805 to press the shaft seal cover into the cylinder 10 Remove the seal guide from the shaft NOTE Position the shaft seal cover as shown in the illus tration The felt pad should also be r...

Page 85: ...Compressor and Clutch Maintenance Rev 1 99 75 Clutch Installation Kit P N 204 890 Snap Ring Pliers P N 204 808 8932c 8932d Shaft Seal Kit P N 204 805 8932e...

Page 86: ...tity of oil that travels around inside the system This oil lubricates all the components returns to the compressor for a while and again travels around the system Adding Extra Oil to the System The in...

Page 87: ...by black oil in the compressor If severe contamination occurs it will be necessary to flush the complete system If flushing is required use industry approved materials In all cases when this occurs y...

Page 88: ...es sor clutch must be perfectly aligned with the engine pulley and any auxiliary idler or belt adjustment pulley compo nents When installing the clutch be sure the shaft drive key is in place and the...

Page 89: ...checked by warming the expansion valve with either a hand or hot towels to see if the valve opens Evacuate the system in the same manner used during installation Install a new drier 8 EXPANSION VALVE...

Page 90: ...mm 4 41 in 112 mm 8 55 in 217 3 mm 4 09 in 104 mm TM 13 HD 6000 rpm 8 0 cid 131 cc 3 28 in 83 3 mm 4 41 in 112 mm 8 55 in 217 3 mm 4 09 in 104 mm TM 13 HD 6000 rpm 8 0 cid 131 cc 2 89 in 73 3 mm 3 86...

Page 91: ...OK replace stator High pressure cutout switch open Eliminate cause of excessive pressure Thermostat faulty Repair or replace Compressor piston stuck Replace compressor Frozen compressor or motor bear...

Page 92: ...inefficient Replace compressor Plugged expansion valve Clean or replace Iced or plugged coil Defrost or clean Defective truck body insulation Correct or replace Too many door openings Keep doors clos...

Page 93: ...level or refrigerant charge Check expansion valve for proper superheat Compressor loses oil Shortage of refrigerant Repair leak and recharge Plugged expansion valve or strainer Clean or replace Wrong...

Page 94: ...er at source 2 Check for power at plug 3 Check for power at compressor contactor 4 Check for power at overload terminals contactor closed 5 Check for power at motor terminals 2 Power at motor terminal...

Page 95: ...restricted dirty Air through condenser too cold ambient Air in refrigerant system Condenser fan blades bent or broken Air short cycling around evaporator coil Air through evaporator restricted Evapora...

Page 96: ...on Leaky bypass check valve Leaky condenser check valve Condenser fan motor not operating Evaporator fan motor not operating Belts are loose Rapid cycling Unit cools in defrost cycle Unit heats in ref...

Page 97: ...efrost Reference Only for Older Units 94 CBci 20 in Cool Reference Only for Older Units 95 CBci 20 in Defrost Reference Only for Older Units 96 Dwg No Drawing Title Rev Page 5D37084 Model 10 and 20 Sc...

Page 98: ...88...

Page 99: ...uction Pressure Regulator 19 Oil Return Line to Compressor 7 Low Pressure Cutout Switch 20 Pilot Solenoid Valve 8 Heat Exchanger 21 Liquid Injection Solenoid Valve 9 Evaporator Coil 22 Receiver Outlet...

Page 100: ...r 19 Liquid Injection Solenoid Valve 7 Suction Pressure Regulator 20 Pilot Solenoid Valve 8 Low Pressure Cutout Switch 21 Liquid Injection Solenoid Valve 9 Heat Exchanger 22 Receiver Outlet Valve 10 E...

Page 101: ...perature Switch 7 Oil Separator 21 Compressor 8 Oil Return Line to Compressor 22 Liquid Injection Line Orifice 9 Low Pressure Cutout Switch 23 Liquid Injection Solenoid Valve 10 Suction Pressure Regul...

Page 102: ...rature Switch 7 Oil Separator 21 Compressor 8 Oil Return Line to Compressor 22 Liquid Injection Line Orifice 9 Low Pressure Cutout Switch 23 Liquid Injection Solenoid Valve 10 Suction Pressure Regulat...

Page 103: ...Pressure Cutout Switch 19 Oil Return Line to Compressor 7 Heat Exchanger 20 Pilot Solenoid Valve 8 Evaporator Coil 21 Liquid Injection Solenoid Valve 9 Expansion Valve 22 Receiver Outlet Valve 10 Pan...

Page 104: ...ressure Cutout Switch 19 Oil Return Line to Compressor 7 Heat Exchanger 20 Pilot Solenoid Valve 8 Evaporator Coil 21 Liquid Injection Solenoid Valve 9 Expansion Valve 22 Receiver Outlet Valve 10 Pan H...

Page 105: ...Pressure Cutout Switch 21 Liquid Injection Line Orifice 8 Suction Pressure Regulator 22 Oil Return Line to Compressor 9 Heat Exchanger 23 Liquid Injection Solenoid Valve 10 Evaporator Coil 24 Drier 11...

Page 106: ...ressure Cutout Switch 21 Liquid Injection Line Orifice 8 Suction Pressure Regulator 22 Oil Return Line to Compressor 9 Heat Exchanger 23 Liquid Injection Solenoid Valve 10 Evaporator Coil 24 Drier 11...

Page 107: ...97 Model 10 and 20 Schematic Diagram...

Page 108: ...98 Model 10 Wiring Diagram...

Page 109: ...99 Model 20 Wiring Diagram...

Page 110: ...100 Model 20 Single Phase with Heat Option Schematic Diagram...

Page 111: ...101 Model 20 Single Phase Wiring Diagram...

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