Carrier 69NT20-531-300 manual If applicable, braze the equalizer connection to, Equalizer line

Page 74

Copper Tube (Apply heat for 10-15 seconds)

Bi-metallic Tube Connection (Apply heat for 2-5 seconds)

Braze Rod

(’Sil-Phos” = 5.5% Silver, 6% Phosphorus)

Use of a wet cloth is not neces- sary due to rapid heat dissipation of the bi--metallic connections

Figure 6-12 Hermetic Thermostatic Expansion Valve Brazing Procedure

 

7. If applicable, braze the equalizer connection to the

 

equalizer line.

 

8. Check superheat (refer to step 6.14.1).

INLET

6.15 EVAPORATOR COIL AND HEATER

 

ASSEMBLY

 

The evaporator section, including the coil, should be

 

cleaned regularly. The preferred cleaning fluid is fresh

 

water or steam. Another recommended cleaner is Oakite

OUTLET

202 or similar, following manufacturer’s instructions.

The two drain pan hoses are routed behind the

 

 

condenser fan motor and compressor. The drain pan

 

Figure 6-13 Economizer Expansion Valve

line(s) must be open to ensure adequate drainage.

6.15.1 Evaporator Coil Replacement

1. Pump down the unit per paragraph 6.4.

a. Pump unit down. (Refer to paragraph 6.4.)

 

2.Remove cushion clamps located on the inlet and out- let lines.

3.Unbraze the equalizer connection (if applicable), the outlet connection and then the inlet connection.

4.Remove insulation (Presstite) from expansion valve bulb.

5.Unstrap the bulb, located below the center of the suc- tion line (4 o’clock position), and remove the valve.

b. Installing the Expansion Valve

1.Clean the suction line with sandpaper before instal- ling bulb to ensure proper heat transfer. Apply ther- mal grease to the indentation in the suction line.

2.Strap the thermal bulb to the suction line, making sure bulb is placed firmly into the suction line. See Figure 6-10 for bulb placement.

3.Insulate the thermal bulb.

4.The economizer expansion valves should be wrapped in a soaked cloth for brazing. See Figure 6-12. Braze inlet connection to inlet line

5.Braze outlet connection to outlet line.

6.Reinstall the cushion clamps on inlet and outlet lines.

b. With power OFF and power plug removed, remove the screws securing the panel covering the evaporator section (upper panel).

c. Disconnect the defrost heater wiring.

d. Disconnect the defrost temperature sensor (see Fig- ure Figure 2-2 from the coil. .

e. Remove middle coil support.

f.Remove the mounting hardware from the coil.

g.Unsolder the two coil connections, one at the distrib- utor and the other at the coil header.

h.After defective coil is removed from unit, remove defrost heaters and install on replacement coil.

i.Install coil assembly by reversing above steps.

j.Leak check connections per paragraph 6.5. Evacuate the unit per paragraph 6.6 and add refrigerant charge per paragraph 6.7.

6.15.2 Evaporator Heater Replacement

a.Before servicing unit, make sure the unit circuit break- ers (CB-1 & CB-2) and the start-stop switch (ST) are in the OFF position, and that the power plug and cable are disconnected.

b. Remove the lower access panel (Figure 2-1) by removing the T.I.R. locking device lockwire and mounting screws.

T-309

6-10

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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 60FBy starting P10-0 over Requirements Control temperature must be at least 7.2C 45FSet point, the test proceeds to test Inapplicable Functions Display Title Data 10 DataCORDER Alarm Indications Operation 69NT Fresh AIR MakeupWill be displayed To start a pre-trip test, do the followingWill 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 Removing the Expansion Valve Two expansion valves are used, the evaporatorWrapped with Insulating compound. See 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

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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