Assessments - 3, GPA: 4
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13 — 38AKS Unit with Access Panels Removed 18 Fan Adjustment — Adjust fan as shown in Fig. 14. NOTE:Dimensionin()isinmillimeters. Fig.14—LocationofProponMotorShaftfromOutsideofOrificeRing Oil Charge — Compressors are factory charged with oil as follows: COMPRESSOR AMOUNT pints (liters) 06E9265 20.0 (9.4) 06E9275 20.0 (9.4) 06E9299 19.0 (9.0) When additional oil or a complete charge is required, use only Carrier-approved compressor oil: Petroleum Specialities Inc...................Cryol 150 Texaco,Inc. .........................CapellaWF-32 WitcoChemicalCorp. ...................Suniso3GS IMPORTANT: Do not use drained oil or use oil that has been exposed to atmosphere. Refer to Carrier Training Booklet, GTAC II, Module 5, for procedures to add oil. To remove oil, isolate the compressor, reclaim internal compressor charge, and use the compressor drain plug. Liquid Shutoff/Charging Valve — Valve is located inside the compressor compartment and is provided with 1.4-in. flare connection for field charging. Capacity Control — Capacity control is by 2 suction pressure actuated unloaders. Each controls 2 cylinders. Unloaders are factory set (see Table 1A or 1B) but may be field adjusted. Number 1 unloader is on cylinder bank on same side of compressor as terminal box. CONTROL SET POINT — The control set point (cylinder load point) is adjustable from 0 to 85 psig (0 to 586 kPag). To adjust, turn control set point adjustment nut (Fig. 15) clockwise to its bottom stop. In this position, set point is 85 psig (586 kPag). Then, turn adjustment counterclockwise to desired control set point. Every full turn counterclockwise decreases set point by 7.5 psig (52 kPag). Fig. 15 — Capacity Control Valve PRESSURE DIFFERENTIAL — The pressure differential (difference between cylinder load and unload points) is adjustable from 6 to 22 psig (41 to 152 kPag). To adjust, turn pressure differential adjustment screw (Fig. 15) counterclockwise to its backstop position. In this position, differential is 6 psig (41 kPag). Then, turn adjustment clockwise to desired pressure differential. Every full turn clockwise increases differential by 1.5 psig (10 kPag). 19 Oil Pressure Safety Switch (OPS) — The OPS in the control circuit stops the compressor and unit, if proper oil pressure differential is not established at start-up or maintained during operation. If OPS stops the unit, determine the cause and correct before restarting unit. Failure to do so will constitute abuse. Equipment failure due to abuse may void the warranty. Compressor Protection CIRCUIT BREAKER — Calibrated trip manual reset, ambient compensated, magnetic breaker protects against motor overload and locked rotor conditions. CONTROL MODULE TIMER — This control protects compressor against short cycling. See Sequence of Operation on page 17. CRANKCASE HEATER — This minimizes absorption of liquid refrigerant by oil in crankcase during brief or extended shutdown periods. IMPORTANT: Never open any switch or disconnect that deenergizes the crankcase heater unless unit is being serviced or is to be shut down for a prolonged period. After a prolonged shutdown on a service job, energize the crankcase heater for 24 hours before starting the compressor. High-Pressure Switch — This switch has fixed, nonadjustable settings. Switch is mounted on the compressor (See Table 4). Low-Pressure Switch — This switch has fixed, nonadjustable settings. Switch is mounted on the compressor. (See Table 4.) Table 4 — Pressure Switch Settings, psig (kPa) HIGH PRESSURE LOW PRESSURE Cutout Cut-in Cutout Cut-in 426±7 (2937 ± 48) 320±20 (2206 ± 138) 27±3 (186 ± 21) 44±5 (303 ± 34) Winter Start Control — Bypass relay timer bypasses low-pressure switch for 2 minutes on unit start-up. Head Pressure Control — Control maintains adequate discharge pressure under low ambient temperature conditions. See Table 5. FAN CYCLING — These 38AKS units have standard provision for fully automatic intermediate-season head pressure control through condenser fan cycling. Fan no. 2 is cycled by a fan cycling pressure switch (FCPS) which responds to variation in discharge pressure. The pressure sensor is located in the liquid line of the refrigerant circuit. Fan no. 3 cycling is controlled by outdoor-air temperature through an air temperature switch (ATS) (38AKS044 units only). Table 5 — Minimum Outdoor-Air Operating Temperature MIN OUTDOOR TEMP, F (C) COND UNIT COMPR Low Ambient TEMP, Standard 38AKS CAP. (%) Control F (C) Unit (MotormasterT) 100 90 (32) 31 (–1) –20 (–29) 028 67 80 (27) 35 (2) –20 (–29) 33 70 (21) 43 (6) –20 (–29) 100 90 (32) 30 (–1) –20 (–29) 034 67 80 (27) 34 (1) –20 (–29) 33 70 (21) 42 (6) –20 (–29) 100 90 (32) 25 (–4) –20 (–29) 044 67 80 (27) 30 (–1) –20 (–29) 33 70 (21) 35 (2) –20 (–29) The ATS is located in the lower divider panel between the compressor compartment and condenser section. Through a hole in the panel, the sensing element is exposed to air entering the no. 1 fan compartment. Fan no. 1 is noncyclin...