Carrier 69NT20-531-300 manual Compressor in a deep vacuum, internal dam- age will result

Page 66

system can be charged. Oil can also be added to the system.

A R-134a manifold gauge/hose set with self-sealing hoses (see Figure 6-4) is required for service of the models covered within this manual. The manifold gauge/hose set is available from Carrier Transicold. (Carrier Transicold P/N 07-00294-00, which includes items 1 through 6, Figure 6-4.) To perform service using the manifold gage/hose set, do the following:

a. Preparing Manifold Gauge/Hose Set For Use

1.If the manifold gauge/hose set is new or was exposed to the atmosphere it will need to be evacuated to remove contaminants and air as follows:

2.Back seat (turn counterclockwise )both field service couplings (see Figure 6-4) and midseat both hand valves.

3.Connect the yellow hose to a vacuum pump and re- frigerant 134a cylinder.

SUCTION

1

DISCHARGE

PRESSURE

PRESSURE

 

GAUGE

 

GAUGE

OPENED

CLOSED

(Backseated )

(Frontseated)

HAND VALVE

HAND VALVE

2.Connect the field service coupling (see Figure 6-4) to the access valve.

3.Turn the field service coupling knob clockwise, which will open the system to the gauge set.

4.To read system pressures: slightly midseat the ser- vice valve.

5.Repeat the procedure to connect the other side of the gauge set.

CAUTION

To prevent trapping liquid refrigerant in the manifold gauge set be sure set is brought to suction pressure before disconnecting.

c. Removing the Manifold Gauge Set

1.While the compressor is still ON, backseat the high side service valve.

2.Midseat both hand valves on the manifold gauge set and allow the pressure in the manifold gauge set to be drawn down to low side pressure. This returns any liquid that may be in the high side hose to the system.

3.Backseat the low side service valve. Backseat both field service couplings and frontseat both manifold set valves. Remove the couplings from the access valves.

4.Install both service valve stem caps and service port caps (finger-tight only).

To Low Side

Access Valve

3

BLUE

6

4

 

Blue Knob

 

To High Side

Access Valve

2

3

 

 

 

 

RED

 

3

 

 

YELLOW

4

5

 

2

Red Knob

6.4 PUMPING THE UNIT DOWN

To service the filter-drier, economizer, expansion valves, moisture-liquid indicator, suction modulation valve, economizer solenoid valve, unloader solenoid valve or evaporator coil, pump the refrigerant into the high side as follows:

CAUTION

The scroll compressor achieves low suction pressure very quickly. Do not operate the

1.Manifold Gauge Set

2.Hose Fitting (0.5-16 Acme)

3.Refrigeration and/or Evacuation Hose

. (SAE J2196/R-134a)

4.Hose Fitting w/O-ring (M14 x 1.5)

5.High Side Field Service Coupling

6.Low Side Field Service Coupling

Figure 6-4 R-134a Manifold Gauge/Hose Set

7.Evacuate to 10 inches of vacuum and then charge with R-134a to a slightly positive pressure of 0.1 kg/ cm@ (1.0 psig).

8.Front seat both manifold gauge set valves and dis- connect from cylinder. The gauge set is now ready for use.

b. Connecting Manifold Gauge/Hose Set

To connect the manifold gauge/hose set for reading pressures, do the following:

1.Remove service valve stem cap and check to make sure it is backseated. Remove access valve cap. (See Figure 6-1)

compressor in a deep vacuum, internal dam- age will result.

a.Attach manifold gauge set to the compressor suction and discharge service valves. Refer to paragraph 6.3.

b.Start the unit and run in the frozen mode (controller set below -10°C) for 10 to 15 minutes.

c.Check function code Cd21 (refer to paragraph 3.2.2). The economizer solenoid valve should be open. If not, continue to run until the valve opens.

d.Frontseat the oil return service valve then, frontseat the liquid line service valve. Place start-stop switch in the OFF position when the suction reaches a positive pressure of 0.1 kg/cm@ (1.0 psig).

e.Frontseat the economizer service valve and then frontseat the suction and discharge service valves. The refrigerant will be trapped between the compres- sor suction service valve and the liquid line valve.

f.Before opening up any part of the system, a slight positive pressure should be indicated on the pressure

T-309

6-2

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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 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 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 Two expansion valves are used, the evaporator Wrapped with Insulating compound. SeeRemoving 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

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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