Carrier 69NT20-531-300 manual Superheat

Page 63

 

 

REMEDY/

CONDITION

POSSIBLE CAUSE

REFERENCE

 

 

SECTION

5.9 CONTROLLER MALFUNCTION

 

 

 

 

 

Defective Sensor

6.22

 

 

 

 

Defective wiring

Check

 

 

 

Will not control

Fuse (F1, F2, F3) blown

Replace

 

Stepper motor suction modulation valve circuit malfunction

6.20

 

 

 

 

Low refrigerant charge

6.7

 

 

 

5.10 NO EVAPORATOR AIR FLOW OR RESTRICTED AIR FLOW

 

 

 

 

Evaporator coil blocked

Frost on coil

5.6

Dirty coil

6.15

 

 

 

 

 

Evaporator fan motor internal protector open

6.17

 

 

 

No or partial evaporator air flow

Evaporator fan motor(s) defective

6.17

 

 

Evaporator fan(s) loose or defective

6.17

 

 

 

 

Evaporator fan contactor defective

Replace

 

 

 

5.11 THERMOSTATIC EXPANSION VALVE MALFUNCTION

 

 

 

 

 

Low refrigerant charge

6.7.1

 

External equalizer line plugged

Open

 

 

 

 

Wax, oil or dirt plugging valve or orifice Ice formation at

6.14

 

valve seat

 

 

Low suction pressure with high

Superheat not correct

6.7.1

superheat

 

 

Power assembly failure

 

 

 

 

Loss of element/bulb charge

6.14

 

 

 

Broken capillary

 

 

 

Foreign material in valve

 

 

 

 

High suction pressure with low

Superheat setting too low

6.14

External equalizer line plugged Ice holding valve open

Open

superheat

 

 

Foreign material in valve

6.14

 

 

 

 

Liquid slugging in compressor

Pin and seat of expansion valve eroded or held open by for-

 

eign material

 

 

6.14

Fluctuating suction pressure

Improper bulb location or installation

 

Low superheat setting

 

 

 

 

 

 

5.12 AUTOTRANSFORMER MALFUNCTION

 

 

 

 

Unit will not start

Circuit breaker (CB-1 or CB-2) tripped

Check

 

 

Power source not turned ON

Check

 

 

 

 

5.13 WATER-COOLED CONDENSER OR WATER PRESSURE SWITCH

 

 

 

 

Condenser fan starts and stops

Water pressure switch malfunction

Check

 

 

Water supply interruption

Check

 

 

 

 

T-309

5-4

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Page 62 Page 64
Contents Service Model Safety Summary 309 Safety-2 Safety-3 309 Table of Contents Table of Contents Check Controller Function Codes Connect Remote MonitoringPrecheck Procedure Checking The Stepper valve Valve ReplacementEvaporator Coil Replacement Evaporator Heater Replacement Replacing The Evaporator Fan AssemblyElectrical Wiring Schematic Refrigeration Circuit Schematic Economized Operation Refrigeration Circuit Schematic Standard OperationList of Tables DataCORDER Configuration VariablesUnit is fitted with a scroll compressor Section IntroductionManual, T-300 Section Description Evaporator Section Compressor Section Condenser Section Communications interface module For further information Module which allow communication with a masterOil level range, with the compressor off Model RSH105 Weight Dry 46.5 kg 103 lbTemperature Approved Oil Mobil ST32 Oil Charge 2957 ml 100 ouncesElectrical Data Safety and Protective Devices Refrigeration Circuit 2.5.1 Standard Operation Standard Operation with Receiver Refrigeration Circuit Schematic -- Economized Operation Section Microprocessor Temperature Control SystemKEY Function Controller Software Modes of Operation Perishable Mode -- Economy Controller Alarms Unit PRE-TRIP Diagnostics DCF02=6 Thermistor inputssupply & returnDCF02=2 DCF02=5 Usda thermistor inputsRaw Data Report for ABC1234567 Standard Configuration Download ReportLogging Interval dCF03 DataCORDER may be powered up in any one of four waysDataView DataCORDER Alarms SnAP CnF11 Defrost Off Selection NoOFFStd, Full CnF33 Snap Freeze OptionDisplay Only Functions Plicable with frozen set points Defrost temperature sensor reading is displayedPossibly delaying a needed defrost cycle Sensor ReadingController Function Codes Sheet 3 Controller Alarm Indications Sheet 1 Controller Alarm Indications Sheet 2 Controller Alarm Indications Sheet 3 Memory failure Error DescriptionOnds Draw test is done after 15 secondsP1-1 Draw test is done after 10 secondsCrease, the test fails Supply is comparedTest fails P6-2Requirements Control temperature must be at least 15.6C 60F Pressure switch is open or the condenser fan switch is openTimer is started Denser fan is started and a 60 second timer is startedRequirements Control temperature must be at least 7.2C 45F Set point, the test proceeds to testBy starting P10-0 over Inapplicable Functions Display Title Data 10 DataCORDER Alarm Indications 69NT Fresh AIR Makeup OperationTo start a pre-trip test, do the following Will be displayedWill be displayed Pull Down Falling Rising Controller Operation -- Perishable ModeController Operation -- Frozen Mode Frozen Mode Defrost Section Troubleshooting Unit will not heat or has insuffi Bent motor shaft Will not initiate defrostSuperheat Unit reads abnormal currents Current sensor wiring Check Valve Frontseated Backseated Section ServiceCompressor 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 Two expansion valves are used, the evaporator Wrapped with Insulating compound. SeeRemoving the Expansion Valve Check superheat refer to step Cleaned regularly. The preferred cleaning fluid is freshIf applicable, braze the equalizer connection to Equalizer line14. Unloader Solenoid Valve Start unit and check operationEvaporator FAN Motor Capacitors Valve Override Controls Precheck Procedure TP1 Mounting Stud Type Cut one replacement sensor wire opposite color Cut wires 5 cm 2 inches from shoulder of defecCut one wire of existing cable 40 mm 1-1/2 inch Shorter than the other wireMaintenance of Painted Surfaces 23 Door Hinge Repair Crack, Chip & Hole Repair Kit 24. Insert Location In-lbs Ft-lbs 13.99 18.86 In-lbs #10 Ft-lbs 12.72 17.1414.6 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

69NT20-531-300 specifications

The Carrier 69NT20-531-300 is a cutting-edge rooftop unit designed to meet the demanding requirements of commercial heating and cooling applications. This model embodies Carrier’s commitment to energy efficiency, reliability, and advanced technological features that enhance indoor comfort while minimizing operational costs.

One of the standout features of the Carrier 69NT20-531-300 is its high energy efficiency. It is equipped with advanced compressor technology that optimizes performance while reducing energy consumption. This ensures that businesses can maintain a comfortable indoor climate without incurring exorbitant utility bills. With a high Seasonal Energy Efficiency Ratio (SEER) and Energy Efficiency Ratio (EER), users can expect not only enhanced comfort but also significant cost savings over time.

The cooling capabilities of the 69NT20-531-300 are complemented by its robust heating options. This unit utilizes a gas heat exchanger, ensuring quick and even heating throughout the space. The combination of cooling and heating capabilities in one compact unit makes it a versatile choice for various applications, including retail spaces, offices, and warehouses.

In addition to its impressive performance specifications, the Carrier 69NT20-531-300 incorporates innovative technologies that further enhance its functionality. The unit comes with advanced controls, allowing for precise temperature regulation and zoning capabilities. This ensures that different areas of a building can maintain their desired temperatures based on usage, improving overall energy efficiency.

Durability is another hallmark of the Carrier 69NT20-531-300. The unit is constructed with high-quality materials and features a weather-proof cabinet that protects it from the elements, ensuring long-term reliability even in harsh conditions. Furthermore, its modular design simplifies maintenance, making it easy for technicians to access critical components.

The 69NT20-531-300 is also designed with low noise operation in mind. It employs sound-dampening technology to ensure that operations are quiet, making it an ideal choice for locations where noise reduction is a priority, such as schools or healthcare facilities.

Overall, the Carrier 69NT20-531-300 stands out as a premier choice for businesses looking for an efficient, reliable, and feature-rich rooftop HVAC unit. Its blend of energy efficiency, advanced technology, and durability positions it as a leader in commercial heating and cooling solutions, making it a valuable investment for any commercial property.
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