Carrier 69NT20-531-300 manual Refrigerant Charge

Page 69

6.7 REFRIGERANT CHARGE

6.7.1 Checking the Refrigerant Charge

NOTE

To avoid damage to the earth’s ozone layer, use a refrigerant recovery system whenever remov- ing refrigerant. When working with refriger- ants you must comply with all local govern- ment environmental laws. In the U.S.A., refer to EPA section 608.

a. Connect the gauge manifold to the compressor dis- charge and suction service valves. For units operating on a water cooled condenser, change over to air cooled operation.

b. Bring the container temperature to approximately 1.7_C (35_F) or -17.8_C (0_F). Then set the control- ler set point to -25_C (-13_F) to ensure that the suc- tion modulation valve is fully open. (Position of the suction modulating valve may be checked at control- ler function code Cd01.)

c. Partially block the condenser coil inlet air. Increase the area blocked until the compressor discharge pres- sure is raised to approximately 12 kg/cm@ (175 psig).

d.On units equipped with a receiver, the level should be between the glasses. On units equipped with a water cooled condenser, the level should be at the center of the glass. If the refrigerant level is not correct, contin- ue with the following paragraphs to add or remove re- frigerant as required.

6.7.2 Adding Refrigerant to System (Full Charge)

a. Evacuate unit and leave in deep vacuum. (Refer to paragraph 6.6.)

b.Place cylinder of R-134a on scale and connect charg- ing line from cylinder to liquid line valve. Purge charging line at liquid line valve and then note weight of cylinder and refrigerant.

c.Open liquid valve on cylinder. Open liquid line valve half-way and allow the liquid refrigerant to flow into the unit until the correct weight of refrigerant (refer to paragraph 2.2) has been added as indicated by scales.

NOTE

It may be necessary to finish charging unit through suction service valve in gas form, due to pressure rise in high side of the system. (Refer to section paragraph 6.7.3)

d. Backseat manual liquid line valve (to close off gauge port). Close liquid valve on cylinder.

e. Start unit in cooling mode. Run approximately 10 minutes and check the refrigerant charge.

6.7.3Adding Refrigerant to System (Partial Charge)

a.Examine the unit refrigerant system for any evidence of leaks. Repair as necessary. (Refer to paragraph 6.5.)

b.Maintain the conditions outlined in paragraph 6.7.1

c.Fully backseat the suction service valve and remove the service port cap.

d.Connect charging line between suction service valve port and cylinder of refrigerant R-134a. Open VAPOR valve.

e.Partially frontseat (turn clockwise) the suction ser- vice valve and slowly add charge until the refrigerant appears at the proper level . Be careful not to frontseat the suction valve fully, if the compressor is operated in a vacuum internal damage may result.

6.8 COMPRESSOR -- Model RSH105

WARNING

Make sure power to the unit is OFF and power plug disconnected before replacing the compressor.

WARNING

Before disassembly of the compressor make sure to relieve the internal pressure very carefully by slightly loosening the couplings to break the seal.

CAUTION

The scroll compressor achieves low suction pressure very quickly. Do not use the com- pressor to evacuate the system below zero psig. Never operate the compressor with the suction or discharge service valves closed (frontseated). Internal damage will result from operating the compressor in a deep vacuum.

6.8.1 Removal and Replacement of Compressor

NOTE

Service compressor contains a nitrogen charge. Due to the hygroscopic nature of the oil, time the compressor is left open to the atmosphere should be minimized as much as possible.

a.Procure a replacement compressor kit. A list of items contained in the compressor kit is provided in Table 6-1.

b.If the compressor is operational, pump the unit down (refer to paragraph 6.4).

6-5

T-309

Page 68 Page 70
Image 69
Page 68 Page 70
Contents Service Model Safety Summary 309 Safety-2 Safety-3 309 Table of Contents Table of Contents Check Controller Function Codes Connect Remote MonitoringEvaporator Coil Replacement Evaporator Heater Replacement Valve ReplacementReplacing The Evaporator Fan Assembly Precheck Procedure Checking The Stepper valveElectrical 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 masterTemperature Model RSH105 Weight Dry 46.5 kg 103 lbApproved Oil Mobil ST32 Oil Charge 2957 ml 100 ounces 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 Section Microprocessor Temperature Control SystemKEY Function Controller Software Modes of Operation Perishable Mode -- Economy Controller Alarms Unit PRE-TRIP Diagnostics DCF02=2 Thermistor inputssupply & returnDCF02=5 Usda thermistor inputs DCF02=6Raw Data Report for ABC1234567 Standard Configuration Download ReportLogging Interval dCF03 DataCORDER may be powered up in any one of four waysDataView DataCORDER Alarms Std, Full CnF11 Defrost Off Selection NoOFFCnF33 Snap Freeze Option SnAPDisplay Only Functions Possibly delaying a needed defrost cycle Defrost temperature sensor reading is displayedSensor Reading Plicable with frozen set pointsController Function Codes Sheet 3 Controller Alarm Indications Sheet 1 Controller Alarm Indications Sheet 2 Controller Alarm Indications Sheet 3 Memory failure Error DescriptionP1-1 Draw test is done after 15 secondsDraw test is done after 10 seconds OndsTest fails Supply is comparedP6-2 Crease, the test failsTimer is started Pressure switch is open or the condenser fan switch is openDenser fan is started and a 60 second timer is started Requirements Control temperature must be at least 15.6C 60FRequirements 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 If applicable, braze the equalizer connection to Cleaned regularly. The preferred cleaning fluid is freshEqualizer line Check superheat refer to step14. Unloader Solenoid Valve Start unit and check operationEvaporator FAN Motor Capacitors Valve Override Controls Precheck Procedure TP1 Mounting Stud Type Cut one wire of existing cable 40 mm 1-1/2 inch Cut wires 5 cm 2 inches from shoulder of defecShorter than the other wire Cut one replacement sensor wire opposite colorMaintenance 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.
Top Page Image Contents