Carrier 69NT20-531-300 manual Section Service, Valve Frontseated Backseated

Page 65

SECTION 6

SERVICE

NOTE

To avoid damage to the earth’s ozone layer, use a refrigerant recovery system whenever removing refrigerant. When working with refrigerants you must comply with all local government environmental laws. In the U.S.A., refer to EPA section 608.

WARNING

Never use air for leak testing. It has been de- termined that pressurized, mixtures of re- frigerant and air can undergo combustion when exposed to an ignition source.

6.1 SECTION LAYOUT

Service procedures are provided herein beginning with refrigeration system service, then refrigeration system component service, electrical system service, temperature recorder service and general service. Refer to the Table Of Contents to locate specific topics.

6.2 SERVICE VALVES

The compressor suction, compressor discharge, compressor economizer, oil return and the liquid line service valves (see Figure 6-1) are provided with a double seat and an access valve which enable servicing of the compressor and refrigerant lines. Turning the valve stem clockwise (all the way forward) will frontseat the valve to close off the line connection and open a path to the access valve. Turning the stem counterclockwise (all the way out) will backseat the valve to open the line connection and close off the path to the access valve.

With the valve stem midway between frontseat and backseat, both of the service valve connections are open to the access valve path.

For example, the valve stem is first fully backseated when connecting a manifold gauge to measure pressure. Then, the valve is opened 1/4 to 1/2 turn to measure the pressure.

2 3

1

 

5

4

 

 

VALVE

VALVE

 

FRONTSEATED

BACKSEATED

 

(Clockwise)

(Counterclockwise)

1.

Line Connection

4.

Valve stem

2.

Access Valve

5.

Compressor Or Filter

3.

Stem Cap

 

Drier Inlet Connection

Figure 6-1 Service Valve

5

4

 

 

 

2

1

3

 

 

VALVE

VALVE

 

FRONTSEATED

BACKSEATED

 

(Clockwise)

(Counterclockwise)

1.

Line Connection

4.

Valve stem

2.

Access Valve

5.

Compressor Inlet

3.

Stem Cap

 

Connection

Figure 6-2 Suction Service Valve

SUCTION

DISCHARGE

PRESSURE

PRESSURE

GAUGE

GAUGE

A

B

C

OPENED (Backseated )

CLOSED (Frontseated)

HAND VALVE

 

HAND VALVE

A. CONNECTION TO LOW SIDE OF SYSTEM B. CONNECTION TO EITHER:

REFRIGERANT CYLINDER OR OIL CONTAINER

C. CONNECTION TO HIGH SIDE OF SYSTEM

Figure 6-3 Manifold Gauge Set 6.3. MANIFOLD GAUGE SET

The manifold gauge set (see Figure 6-3) is used to determine system operating pressure, add refrigerant charge, and to equalize or evacuate the system.

When the suction pressure hand valve is frontseated (turned all the way in), the suction (low) pressure can be checked. When the discharge pressure hand valve is frontseated, the discharge (high) pressure can be checked. When both valves are open (turned counter-clockwise all the way out), high pressure vapor will flow into the low side. When the suction pressure valve is open and the discharge pressure valve shut, the

6-1

T-309

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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 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 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 Removing the Expansion Valve Two expansion valves are used, the evaporatorWrapped with Insulating compound. See 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
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