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Resumen del manual
The refrigerant can be pumped for service work to either the chiller compressor vessel or chiller condenser vessel by using the optional pumpout system. If a pumpout storage tank is supplied, the refrigerant can be isolated in the storage tank. The following procedures describe how to transfer refrigerant from vessel to vessel and perform chiller evacuations. Always run the chiller cooler and condenser water pumps and always charge or transfer refrigerant as a gas when the chiller pressure is less than 30 psig (207 kPa). Below these pressures, liquid refrigerant flashes into gas, resulting in extremely low temperatures in the cooler/condenser tubes and possibly causing tube freeze-up. During transfer of refrigerant into and out of the optional storage tank, carefully monitor the storage tank level gage. Do not fill the tank more than 90% of capacity to allow for refrigerant expansion. Overfilling may result in damage to the tank or personal injury. Do not mix refrigerants from chillers that use different compressor oils. Compressor damage can result. Operating the Optional Pumpout Unit 1. Be sure that the suction and the discharge service valves on the optional pumpout compressor are open (back- seated) during operation. Rotate the valve stem fully counterclockwise to open. Front-seating the valve closes the refrigerant line and opens the gage port to compressor pressure. 2. Ensure that the compressor hold-down bolts have been loosened to allow free spring travel. 3. Open the refrigerant inlet valve on the pumpout compressor. 4. Oil should be visible in the pumpout unit compressor sight glass under all operating conditions and during shutdown. If oil is low, add oil as described under Optional Pumpout System Maintenance section, page 75. The pumpout unit control wiring schematic is detailed in Fig. 35. TO READ REFRIGERANT PRESSURES during pumpout or leak testing: 1. The CVC/ICVC display on the chiller control panel is suitable for determining refrigerant-side pressures and low (soft) vacuum. To assure the desired range and accuracy when measuring evacuation and dehydration, use a quality vacuum indicator or manometer. This can be placed on the Schrader connections on each vessel (Fig. 9) by removing the pressure transducer. 2. To determine pumpout storage tank pressure, a 30 in. -0-400 psi (-101-0-2769 kPa) gage is attached to the storage tank. 3. Refer to Fig. 29, 30, and 36 for valve locations and numbers. Transfer, addition, or removal of refrigerant in spring- isolated chillers may place severe stress on external piping if springs have not been blocked in both up and down directions. 67 68 DATE REFRIGERATION LOG CARRIER 19XR HERMETIC CENTRIFUGAL REFRIGERATION MACHINEPlant MACHINE MODEL NO. MACHINE SERIAL NO. REFRIGERANT TYPE DATE COOLER CONDENSER COMPRESSOR OPERATORINITIALS REMARKSTIME Refrigerant Water Refrigerant Water BEARINGTEMP Oil Motor Press. Temp Pressure Temp Press. Temp Pressure Temp Press.Diff. Temp(reservoir) Level FLA In Out GPM In Out In Out GPM In Out Amperage(or vaneposition) REMARKS: Indicate shutdowns on safety controls, repairs made and oil or refrigerant added or removed. Include amounts. Fig. 34 — Refrigeration Log LEGEND C— Contactor FU — Fuse, 3 Amps HP — High-Pressure Cutout OL — Compressor Overload T’STAT — Internal Thermostat Compressor Terminal Contactor Terminal Overload Terminal Pumpout Unit Terminal *Bimetal thermal protector imbedded in motor winding. Fig. 35 — 19XR Pumpout Unit Wiring Schematic the CONTROL TEST table to turn on the water pumps and monitor pressures. If the chilled water and condenser water pumps are not controlled by the PIC II, these pumps must be started and stopped manually at the appropriate times during the refrigerant transfer procedure. b. Close pumpout unit valves 2, 4, 5, 8, and 10, and close chiller charging valve 7; open chiller isolation valves 11, 12, 13, and 14 (if present). c. Open pumpout unit/storage tank valves 3 and 6, open chiller valves 1a and 1b. VALVE 1a 1b 2 3 4 5 6 7 8 10 11 12 13 14 CONDITION C C C C C C Follow Steps d and e carefully to prevent damage from freeze-up. d. Slowly open valve 5 to increase chiller pressure to 68 psig 35 psig (141 kPa) for HFC-134a. Feed refrigerant slowly to prevent freeze up. e. Open valve 5 fully after the pressure rises above the freeze point of the refrigerant. Open liquid line valves 7 and 10 until refrigerant pressure equalizes. VALVE 1a 1b 2 3 4 5 6 7 8 10 11 12 13 14 CONDITION C C C 2. Transfer the remaining refrigerant. a. Close valve 5 and open valve 4. OIL RETURN LINE CONNECTION CONDENSER WATER REFRIGERANT INLET VALVE CONNECTIONS Fig. 36 — Optional Pumpout Unit Chillers with Storage Tanks — If the chiller has isolation valves, leave them open for the following procedures. The letter “C” describes a closed valve. See Fig. 17, 18, 29, and 30. TRANSFER REFRIGERANT FROM PUMPOUT STORAGE TANK TO CHILLER 1. Equalize refrigerant pressure. a. Use the PIC II terminate lockout function on the PUMPDOW...
Otros modelos de este manual:Refrigeradores - XRV (4.03 mb)
Refrigeradores - XRV (4.03 mb)