Carrier 50TC*17 Series Service And Maintenance Instructions

4Removing the Return Air Filters1. Remove the return air filter and indoor coil accesspanel. See Fig. 1.2. Reach inside and remove filters from the filter rack.3. Replace these filters as required with similar replace-ment filters of same size.4. Re−install the return air filter and indoor coil accesspanel.Outdoor Air HoodOutside air hood inlet screens are permanentaluminum−mesh type filters. See Fig. 2. Inspect thesescreens for cleanliness. Remove the screens whencleaning is required. Clean by washing with hotlow−pressure water and soft detergent and replace allscreens before restarting the unit. Observe the flowdirection arrows on the side of each filter frame.Economizer Inlet Air ScreenThis air screen is retained by spring clips under the topedge of the hood. (See Fig. 3.)CLEANABLEALUMINUMSCREENHOODFILTERCLIPOUTSIDEAIRBAROMETRICRELIEFDIVIDER17 1/4(438 mm)C06027Fig. 3 − Inlet Air Screen InstallationRemove screens be removing the screws in the horizontalclips on the leading edge of the hood. Slide the filters out.See Fig. 3.Install the filters by sliding clean or new filters into thehood side retainers. Once positioned, re−install thehorizontal clips.SUPPLY FAN (BLOWER) SECTIONELECTRICAL SHOCK HAZARDFailure to follow this warning could cause personalinjury or death.Before performing service or maintenance operationson the fan system, shut off all unit power andLockout/Tagout the unit disconnect switch. DO NOTreach into the fan section with power still applied tothe unit.! WARNINGSupply Fan AssemblyThe supply fan system consists of two forward−curvedcentrifugal blower wheels mounted on a solid blower shaftthat is supported by two greasable pillow block concentricbearings. A fixed−pitch driven fan pulley is attached tothe fan shaft and an adjustable−pitch driver pulley ismounted on the motor. The pulleys are connected using aV−belt. (See Fig. 4.)Vertical Supply ModelsThe two fan wheels used on the vertical supply models arethe same: 15″ diameter x 15″ width. This arrangementprovides uniform airflow distribution across the width ofthe evaporator coil, electric heater, and into the supplyduct.Horizontal Supply ModelsThe horizontal supply models have two different fanwheel sizes on a single shaft. The front side wheel is 18″diameter x 15″ wide, while the rear side fan is 15″diameter x 11″ wide. This arrangement promotes uniformairflow across the width of the evaporator coil and heaterassembly while using a supply outlet on the rear side ofthe unit.NOTE: This major difference in the fan system designmakes it impossible to field−convert the 50TC unit’ssupply fan outlet configuration.VERTICAL SUPPLY FANSHORIZONTAL SUPPLY FANS15” X 15” SUPPLY FANS15” X 11” SUPPLY FAN18” X 15” SUPPLY FANC12683Fig. 4 − Supply Fan ArrangementsBeltCheck the belt condition and tension quarterly. Inspect thebelt for signs of cracking, fraying or glazing along theinside surfaces. Check belt tension by using a spring−force