Assessments - 2, GPA: 4.5
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III. INTERNAL CURRENT AND TEMPERATURE SENSITIVE OVERLOAD Control resets automatically when internal compressor motor temperature drops to a safe level (overloads may require up to 45 minutes to reset). When an internal overload is suspected of being open, check by using an ohmmeter or continuity tester. IV. PUMPDOWN PROCEDURE The system may be pumped down in order to make repairs on low side without losing complete refrigerant charge. To pump down: 1. Attach pressure gage to suction service valve gage port. 2. Frontseat the liquid line valve. CAUTION: The 538J unit coils hold only the factory-designated amount of refrigerant. Additional refrigerant may cause units to relieve pressure through compressor internal pressure relief valve (indicated by sudden rise of suction pressure) before suction pressure reaches 5 psig (34 kPa). If this occurs, shut off unit immediately, then frontseat the suction valve and remove and reclaim excess refrigerant following accepted practice. 3. Start unit and run until suction pressure reaches 5 psig (34 kPa). 4. Shut unit off and frontseat suction valve. 5. Depressurize low side of unit and recover refrigerant following accepted practice. —7— Table 3 — Electrical Data 538J V-PH-Hz OPERATIONAL VOLTAGE* COMPRESSOR POWER SUPPLY Min Max RLA LRA Fan FLA MCA Max Fuse† or HACR-Type Ckt Bkr Amps 018 208/230-1-60 187 254 10.7 47.0 .70 14.1 25 024 13.2 59.0 .70 17.2 30 030 15.7 73.0 .70 20.3 35 036 15.7 93.0 .70 20.3 35 048 24.3 131.0 .45 31.8 50 060 28.6 170.0 .45 37.2 65 LEGEND FLA — Full Load Amps HACR — Heating, Air Conditioning, Refrigeration LRA — Locked Rotor Amps MCA — Minimum Circuit Amps per NEC Section 430-24 NEC — National Electrical Code (U.S.A. Standard) RLA — Rated Load Amps (Compressor) *Permissible limits of the voltage range at which unit will operate satisfactorily. †Time-delay fuse. NOTES: 1. Control circuit is 24 v on all units and requires an external power source. V. LOW PRESSURE SWITCH This switch, mounted on the suction line, has fixed nonadjustable settings. To check pressure switch, attach pressure gage to suction service valve gage port. Slowly close liquid shutoff valve and allow compressor to pump down. Do not allow compressor to pump down below 2 psig (14 kPa). Compressor should shut down when suction pressure drops to cutout pressure in Tables 1A and 1B, and should restart when pressure builds up to cut-in pressure shown after accessory CLO (compressor lockout) switch has been reset and accessory Time Guard® II device has completed its timing cycle. VI. SERVICE VALVES The service valves in the outdoor unit come from the factory frontseated. This means the refrigerant charge is isolated from the line-set connection ports. To prevent damage to the valve, use a wet cloth or other acceptable heat sink material on the valve before brazing. The service valves must be backseated (turned counterclockwise until seated) before the service port caps can be removed and the hoses of the gage manifold connected. In this position, refrigerant has access from the through outdoor and indoor unit. The service valve cannot be field repaired; only a complete valve or valve stem seal and service port caps are available for replacement. VII. ACCURATER® (BYPASS TYPE) DEVICE See Fig. 4 for bypass type AccuRater device components. The piston has a refrigerant metering hole through it. The retainer forms a stop for the piston in the refrigerant bypass mode and a sealing surface for liquid line flare connection. To check, clean or replace piston: 1. Shut off power to unit. 2. Pump down using Pumpdown Procedure section on page 7. 3. Remove liquid line flare connection from AccuRater device. 4. Pull retainer out of body, being careful not to scratch flare sealing surface. If retainer does not pull out easily, carefully use locking pliers to remove retainer. 5. Slide piston out by inserting a small soft wire, with small kinks, through metering hole. Ensure metering 2. All motors and compressors contain internal overload protection. 3. In compliance with NEC (U.S.A. Standard) requirements for multimotor and combination load equipment (refer to NEC Articles 430 and 440), the overcurrent protective device for the unit shall be fuse or HACR breaker. 4. Motor RLA values are established in accordance with UL (Underwriters’ Laboratories) Standard 465 (U.S.A. Standard). hole, sealing surface around piston cones, and fluted portion of piston are not damaged. 6. Clean piston refrigerant metering hole. 7. Replace retainer O-ring before reassembling Accu- Rater device (O-ring part no. 99CC501052). VIII. REFRIGERANT CHARGING WARNING: To prevent personal injury, wear safety glasses and gloves when handling refrigerant. Do not overcharge system — this can cause compressor flooding. NOTE: Do not vent or depressurize unit refrigerant to atmosphere. Remove and recover refrigerant following practice. A. Superheat Method (Cooling, Non-TXV) To check and adjust charge during cooling season, use Tables 4A-5...