Carrier WeatherExpert 48N2 Controls, Start-up, Operation, Service And Troubleshooting Instructions

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Carrier WeatherExpert 48N2 Controls, Start-up, Operation, Service And Troubleshooting Instructions Manual pdf 159 page image

1593. Start high pressure water sprayer and purge any soap orindustrial cleaners from sprayer before cleaning condens-er coils. Only clean potable water is authorized for clean-ing condenser coils.4. Clean condenser face by spraying the core steady anduniformly from top to bottom while directing the spraystraight toward the core. Do not exceed 900 psig or30 degree angle. The nozzle must be at least 12 in. fromthe core face. Reduce pressure and use caution to preventdamage to air centers.CONDENSATE DRAIN — Check and clean each year atstart of cooling season. In winter, keep drains and traps dry.FILTERS — Clean or replace at start of each heating and cool-ing season, or more often if operating conditions require. Referto Installation Instructions for type and size.1. Remove economizer outdoor-air filters from the hoods byremoving the filter retainers.2. Clean filters with steam or hot water and mild detergent.3. Reinstall filters in hoods after cleaning. Never replacecleanable filters with throwaway filters.OUTDOOR-AIR INLET SCREENS — Clean screens withsteam or hot water and a mild detergent. Do not use disposablefilters in place of screens.LubricationFAN SHAFT BEARINGS — Lubricate fan shaft bearings atleast once a year with suitable bearing grease. Optional extend-ed grease lines may be provided on pulley side of blower. Typ-ical lubricants are given below:*Preferred lubricant because it contains rust and oxidation inhibitors.FAN MOTOR BEARINGS — The condenser-fan motorshave sealed bearings so no field lubrication is required.DOOR HINGES — All door hinges should be lubricated atleast once a year.Electronic Expansion Valve (EXV) — Each circuithas 2 EXVs on which superheat may be adjusted if necessaryby using the ComfortLink controller. Adjustment is not nor-mally required or recommended.The TXV is set to maintain 10 to 13 F superheat leaving theevaporator coil. It controls the flow of refrigerant to the evapo-rator coils.Refrigeration CircuitsLEAK TESTING — Units are shipped with a full operatingcharge of R-410A (see unit nameplate). If there is no pressurein the system, introduce enough nitrogen to search for the leak.Repair the leak using good refrigeration practices. After leaksare repaired, system must be evacuated and dehydratedusing methods described in GTAC II, Module 4, SystemDehydration.REFRIGERANT CHARGE — Amount of refrigerant chargeis listed on unit nameplate. Refer to Carrier GTAC II; Module5; Charging, Recovery, Recycling, and Reclamation section forcharging methods and procedures.Unit panels must be in place when unit is operating duringcharging procedure.NOTE: Do not use recycled refrigerant as it may containcontaminants.NO CHARGE — Use standard evacuating techniques. Afterevacuating system, weigh in the specified amount of refriger-ant from the unit nameplate.LOW CHARGE COOLING — Due to the compact, all alu-minum design, microchannel heat exchangers will reducerefrigerant charge and overall operating weight. As a result,charging procedures for MCHX units require more accuratemeasurement techniques. Charge should be added in smallincrements. Using cooling charging charts provided (Fig. 58-79), add or remove refrigerant until conditions of the chart aremet. As conditions get close to the point on the chart, add orremove charge in 1/4 lb increments until complete. Ensure thatall fans are on and all compressors are running when usingcharging charts.To Use the Cooling Charging Chart — Use the outdoor airtemperature, saturated suction temperature (SST) and saturatedcondensing temperature (available on the ComfortLink dis-play), and find the intersection point on the cooling chargingchart. If intersection point is above the line, carefully recoversome of the refrigerant. If intersection point is below the line,carefully add refrigerant.NOTE: Indoor-air cfm must be within normal operating rangeof unit.Units With Humidi-MiZer® Adaptive DehumidificationSystemNOTE: All circuits must be running in normal cooling mode.Indoor airflow must be within specified air quantity limits forcooling. All outdoor fans must be on and running at normalspeed.Use the following procedure to adjust charge on Circuit Bof Humidi-MiZer equipped units:1. Start all compressors and outdoor fans. Allow unit to runfor 5-minutes.2. Switch system to run in a Dehumidification mode for 5minutes by switching RHV to ON through the ServiceTest function (Service TestCOOLRHV).3. At the end of the 5-minute period, switch back into Cool-ing mode through the Service Test function (ServiceTestCOOLRHV) by switching RHV to OFF.4. Using the cooling charging charts provided (Fig. 58-79),add or remove refrigerant until conditions of the chart aremet. As conditions get close to the point on the chart, addor remove charge in 1/4 lb increments until complete. Seeparagraph “To Use the Cooling Charging Chart” for addi-tional instructions.5. If a charge adjustment was necessary in Step 4, then re-peat the steps in this paragraph (starting with Step 2) untilno charge adjustment is necessary. When no more chargeadjustment is necessary after switching from a Dehumidi-fication Mode to a Cooling Mode (Steps 2 and 3), thenthe charge adjustment procedure is complete.CAUTIONExcessive water pressure will fracture the braze betweenair centers and refrigerant tubes.MANUFACTURER LUBRICANTTexaco Regal AFB-2*Mobil Mobilplex EP No. 1Sunoco Prestige 42Texaco Multifak 2