Carrier 50JZ024 Installation, Start-up And Service Instructions Manual

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Contents

SPECIAL PROCEDURES FOR 208V OPERATION1. Be sure unit disconnect switch is open.2. Disconnect the yellow primary lead (w110) from the trans-former. See unit wiring label (Fig. 12 and 13).3. Connect the yellow primary lead (w110) to the transformerterminal labeled 200v.Indoor blower-motor speeds may need to be changed for 208voperation. Refer to indoor airflow and airflow adjustments section.PRE-START-UPFailure to observe the following warnings could result inserious personal injury or death:1. Follow recognized safety practices and wear protectivegoggles when checking or servicing refrigerant system.2. Do not operate compressor or provide any electric power tounit unless compressor terminal cover is in place andsecured.3. Do not remove compressor terminal cover until all electri-cal sources are disconnected.4. Relieve and recover all refrigerant from both high- andlow-pressure sides of system before touching or disturbinganything inside terminal box if refrigerant leak is suspectedaround compressor terminals.5. Never attempt to repair soldered connection while refrig-erant system is under pressure.6. Do not use torch to remove any component. Systemcontains oil and refrigerant under pressure.To remove a component, wear protective goggles andproceed as follows:a. Shut off electrical power to unit.b. Relieve and reclaim all refrigerant from system usingboth high- and low-pressure ports.c. Cut component connecting tubing with tubing cutter andremove component from unit.d. Carefully unsweat remaining tubing stubs when neces-sary. Oil can ignite when exposed to torch flame.Use the Start-Up Checklist supplied at the end of this book andproceed as follows to inspect and prepare the unit for initialstart-up:1. Remove all access panels.2. Read and follow instructions on all DANGER, WARNING,CAUTION, and INFORMATION labels attached to, orshipped with, unit.3. Make the following inspections:a. Inspect for shipping and handling damages such as brokenlines, loose parts, disconnected wires, etc.b. Inspect for oil at all refrigerant tubing connections and onunit base. Detecting oil generally indicates a refrigerantleak. Leak-test all refrigerant tubing connections usingelectronic leak detector, or liquid-soap solution. If a refrig-erant leak is detected, see following Check for RefrigerantLeaks section.c. Inspect all field and factory-wiring connections. Be surethat connections are completed and tight.d. Inspect coil fins. If damaged during shipping and handling,carefully straighten fins with a fin comb.4. Verify the following conditions:a. Make sure that outdoor-fan blade is correctly positioned infan orifice.b. Make sure that air filter(s) is in place.c. Make sure that condensate drain pan and trap are filled withwater to ensure proper drainage.d. Make sure that all tools and miscellaneous loose parts havebeen removed.5. Compressors are internally spring mounted. Do not loosen orremove compressor hold-down bolts.6. Each unit system has 2 Schrader-type ports, one low-sideSchrader fitting located on the suction line, and one high-sideSchrader fitting located on the compressor discharge line. Besure that caps on the ports are tight.START-UPUsing the Start-Up Checklist supplied at the end of this book,proceed as follows:Step 1—Check for Refrigerant LeaksLocate and repair refrigerant leaks and charge the unit as follows:1. Use both high- and low-pressure ports to relieve systempressure and reclaim remaining refrigerant.2. Repair leak following accepted practices.NOTE: Replace biflow filter drier whenever the system hasbeen opened for repair.3. Check system for leaks using an approved method.4. Evacuate refrigerant system and reclaim refrigerant if noadditional leaks are found.5. Charge unit with R-410A refrigerant, using a volumetric-charging cylinder or accurate scale. Refer to unit rating platefor required charge.Step 2—Start-Up AdjustmentsComplete the required procedures given in the Pre-Start-Upsection on this page before starting the unit. Do not jumper anysafety devices when operating the unit. Do not operate the unit inCooling mode when the outdoor temperature is below 40°F (unlessaccessory low-ambient kit is installed). Do not rapid-cycle thecompressor. Allow 5 minutes between ‘‘on’’ cycles to preventcompressor damage.CHECKING COOLING AND HEATING CONTROL OPERA-TION — Start and check the unit for proper control operation asfollows:Fig. 19—Transformer Label C99058TRANSFORMER CONTAINS A MANUALRESET OVERCURRENT PROTECTORIT WILL NOT AUTOMATICALLY RESETDISCONNECT POWER PRIOR TOSERVICINGTHIS COMPARTMENT MUST BE CLOSEDEXCEPT WHEN SERVICINGFig. 20—Fan Blade ClearanceC99009FAN GRILLEMOTOR1/8" MAX BETWEENMOTOR AND FAN HUB MOTOR SHAFT14