Carrier 69NT20-531-300 manual Frozen Mode

Page 58

noid valve changing from economized operation to unloaded operation. (As shown in Figure 4-5)

d.The controller monitors the supply air. Once the sup- ply air falls below set point the controller periodically records the supply air temperature, set point and time. A calculation is then performed to determine temper- ature drift from set point over time.

e.If the calculation determines cooling is no longer re- quired, contacts TD and TN are opened to de-energize compressor motor and condenser fan motor. The cool light is also de-energized.

f.The evaporator fan motors continue to run to circulate air throughout the container. The in-range light re- mains illuminated as long as the supply air is within tolerance of set point.

g.If the supply air temperature increases to 0.2_C (0.4_F) above set point and the three minute off time has elapsed, relays TD, TU and TN are energized to restart the compressor and condenser fan motors in unloaded operation. The cool light is also illumi- nated.

ENERGIZED

 

DE--ENERGIZED

CONTROL TRANSFORMER

FOR FULL DIAGRAM AND

 

LEGEND, SEE SECTION 7

 

POWER TO

CONTROLLER

T6

PB

 

PA

TD

T6

PA

PB

SIGNAL TO

 

 

 

CONTROLLER

TU

USV

 

TS

 

 

ESV

NOTE: HIGH SPEED EVAPORATOR FAN SHOWN. FOR LOW SPEED CONTACT TE IS DE--ENERGIZED AND CONTACT TV IS ENERGIZED

Figure 4-5 Perishable Mode Heating

4.9.3Sequence Of Operation -- Perishable Mode Heating

a.If the air temperature decreases 0.5_C (0.9_F) below set point, the system enters the heating mode. (See Figure 4-2). The controller closes contacts TH (see Figure 4-5) to allow power flow through the heat ter- mination thermostat (HTT) to energize the heaters (HR). The HEAT light is also illuminated. The evapo- rator fans continue to run to circulate air throughout the container.

b.When the temperature rises to 0.2_C (0.4_F) above set point, contact TH opens to de-energize the heat- ers. The HEAT light is also de-energized. The evapo-

rator fans continue to run to circulate air throughout the container.

c. A safety heater termination thermostat (HTT), at- tached to an evaporator coil support, will open the heating circuit if overheating occurs.

4.9.4Sequence Of operation -- Frozen Mode Cool- ing

a. With supply air temperature above set point and de- creasing, the unit will transition to economized cool- ing with the condenser fan motor (CF), compressor motor (CH), economizer solenoid valve (ESV), low speed evaporator fan motors (ES) energized and the COOL light illuminated. (See Figure 4-6.)

b.When the air temperature decreases to a predeter- mined tolerance above set point, the in-range light is

illuminated.

 

 

 

ENERGIZED

 

 

 

DE--ENERGIZED

CONTROL TRANSFORMER

FOR FULL DIAGRAM AND

 

 

 

LEGEND, SEE SECTION 7

 

 

 

POWER TO

 

 

 

CONTROLLER

 

 

 

T6

PB

 

PA

TD

T6

PA

PB

SIGNAL TO

 

 

 

CONTROLLER

TU

USV

 

TS

 

 

ESV

Figure 4-6 Frozen Mode

c. When the return air temperature decreases to 0.2_C (0.4_F) below set point, contacts TD, TS and TN are opened to de-energize the compressor, economizer solenoid valve and condenser fan motors. The cool light is also de-energized.

d. The evaporator fan motors continue to run in low speed to circulate air throughout the container. The in-range light remains illuminated as long as the re- turn air is within tolerance of set point.

e.When return air temperature is 10_C (18_F) or more below set point, the evaporator fans are brought to high speed.

f.When the return air temperature increases to 0.2_C (0.4_F) above set point and the three minute off time has elapsed, relays TD, TS and TN are energizes to restart the compressor and condenser fan motors. The cool light is illuminated.

4.9.5 Sequence Of Operation -- Defrost

The defrost cycle may consist of up to three distinct operations. The first is de-icing of the coil, the second is a probe check cycle and the third is snap freeze.

T-309

4-6

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Contents Service Model Safety Summary 309 Safety-2 Safety-3 309 Table of Contents Table of Contents Connect Remote Monitoring Check Controller Function CodesReplacing The Evaporator Fan Assembly Valve ReplacementEvaporator Coil Replacement Evaporator Heater Replacement Precheck Procedure Checking The Stepper valveElectrical Wiring Schematic Refrigeration Circuit Schematic Standard Operation Refrigeration Circuit Schematic Economized OperationDataCORDER Configuration Variables List of TablesSection Introduction Unit is fitted with a scroll compressorManual, T-300 Section Description Evaporator Section Compressor Section Condenser Section Module which allow communication with a master Communications interface module For further informationApproved Oil Mobil ST32 Oil Charge 2957 ml 100 ounces Model RSH105 Weight Dry 46.5 kg 103 lbTemperature Oil level range, with the compressor offElectrical Data Safety and Protective Devices Refrigeration Circuit 2.5.1 Standard Operation Standard Operation with Receiver Refrigeration Circuit Schematic -- Economized Operation Temperature Control System Section MicroprocessorKEY Function Controller Software Modes of Operation Perishable Mode -- Economy Controller Alarms Unit PRE-TRIP Diagnostics DCF02=5 Usda thermistor inputs Thermistor inputssupply & returnDCF02=2 DCF02=6Standard Configuration Download Report Raw Data Report for ABC1234567DataCORDER may be powered up in any one of four ways Logging Interval dCF03DataView DataCORDER Alarms CnF33 Snap Freeze Option CnF11 Defrost Off Selection NoOFFStd, Full SnAPDisplay Only Functions Sensor Reading Defrost temperature sensor reading is displayedPossibly delaying a needed defrost cycle Plicable with frozen set pointsController Function Codes Sheet 3 Controller Alarm Indications Sheet 1 Controller Alarm Indications Sheet 2 Controller Alarm Indications Sheet 3 Error Description Memory failureDraw test is done after 10 seconds Draw test is done after 15 secondsP1-1 OndsP6-2 Supply is comparedTest fails Crease, the test failsDenser fan is started and a 60 second timer is started Pressure switch is open or the condenser fan switch is openTimer is started Requirements Control temperature must be at least 15.6C 60FSet point, the test proceeds to test Requirements Control temperature must be at least 7.2C 45FBy starting P10-0 over Inapplicable Functions Display Title Data 10 DataCORDER Alarm Indications Operation 69NT Fresh AIR MakeupWill be displayed To start a pre-trip test, do the following Will be displayed Controller Operation -- Perishable Mode Pull Down Falling RisingController Operation -- Frozen Mode Frozen Mode Defrost Section Troubleshooting Unit will not heat or has insuffi Will not initiate defrost Bent motor shaftSuperheat Unit reads abnormal currents Current sensor wiring Check Section Service Valve Frontseated BackseatedCompressor in a deep vacuum, internal dam- age will result Refrigerant Leak Checking Remove all refrigerant using a refrigerant recovery system Refrigerant Charge Compressor Upper Mounting Compressor OIL Level Condenser FAN and Motor Assembly Wrapped with Insulating compound. See Two expansion valves are used, the evaporatorRemoving the Expansion Valve Equalizer line Cleaned regularly. The preferred cleaning fluid is freshIf applicable, braze the equalizer connection to Check superheat refer to stepStart unit and check operation 14. Unloader Solenoid ValveEvaporator FAN Motor Capacitors Valve Override Controls Precheck Procedure TP1 Mounting Stud Type Shorter than the other wire Cut wires 5 cm 2 inches from shoulder of defecCut one wire of existing cable 40 mm 1-1/2 inch Cut one replacement sensor wire opposite colorMaintenance of Painted Surfaces 23 Door Hinge Repair Crack, Chip & Hole Repair Kit 24. Insert Location In-lbs #10 Ft-lbs 12.72 17.14 In-lbs Ft-lbs 13.99 18.8614.6 49.4 37.08 12.3 41.6 31.25 32.8 24.64 22.7 17.00 11.9 Section Electrical Wiring Schematic Schematic Diagram Wiring Diagram Sheet 1 Wiring Diagram Sheet 2 Index 309 Index-2
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