Carrier 50TC*17 Series Service And Maintenance Instructions

7NOTE: The Remote VFD Keypad is a field-installed option. It is not included as part of the Factory installed VFDoption. See “Variable Frequency Drive (VFD) Installation, Setup and Troubleshooting Supplement” for wiringschematics and performance charts and configuration. SeeFig. 9 for location of the (VFD) as mounted on the various50HC models.VariableFrequencyDrive (VFD)C11531Fig. 9 − VFD Location for 50HC 15–27.5 UnitsADDITIONAL VFD INSTALLATIONAND TROUBLESHOOTINGAdditional installation, wiring and troubleshooting information for the VFD can be found in the following manuals: “Variable Frequency Drive (VFD) Installation, Setupand Troubleshooting Supplement.”MotorWhen replacing the motor, use the following steps. SeeFig. 10.BLOWER PULLEYV-BELTMOTOR PULLEYMOTORMOTOR MOUNTINGBOLTS (4)JACK BOLTJAM NUT (2)JACK BOLT (2)C12034Fig. 10 − Replacing Belt Driven MotorReplacing the Motor1. Turn off all electrical power to the unit. Use approvedlockout/tagout procedures on all electrical powersources.2. Remove the cover on the motor connection box.3. Disconnect all electrical leads to the motor.4. Loosen the two jack bolt jamnuts on the motormounting bracket.5. Turn the two jack bolts counterclockwise until themotor assembly moves closer to the blower pulley.6. Remove the V-belt from the blower pulley and motorpulley.EQUIPMENT DAMAGE HAZARDFailure to follow this CAUTION can result inpremature wear and damage to equipment.Do not use a screwdriver or pry−bar to place the newV−belt in the pulley groove. This can cause stress onthe V−belt and the pulley, resulting in premature wearon the V−belt and damage to the pulley.CAUTION!7. Loosen the four mounting bracket bolts and lockwashers.8. Remove four bolts, four flat washers, four lock washers and four nuts attaching the motor mounting plateto the unit. Discard all lock washers.9. Remove the motor and motor mounting bracket fromthe unit.10. Remove four bolts, flat washers, lock washers andsingle external-tooth lock washer attaching the motorto the motor mounting plate. Discard all lock washersand external-tooth lock washer.11. Lift the motor from the motor mounting plate and setaside.12. Slide the motor mounting band from the old motor.13. Slide the motor mounting band onto the new motorand set the motor onto the motor mounting plate.14. Remove the variable pitch pulley from the old motorand attach it to the new motor.15. Inspect the variable pitch pulley for cracks and wear.Replace the pulley if necessary.16. Secure the pulley to the motor by tightening the pulley setscrew to the motor shaft.17. Insert four bolts and flat washers through the mounting holes on the motor and into holes on the motormounting plate.18. On one bolt, place a new external-tooth lock washerbetween the motor and motor mounting band.19. Make sure the teeth of the external-tooth lock washermake contact with the painted base of the motor. Thiswasher is essential for properly grounding the motor.20. Install four new lock washers and four nuts on thebolts on the bottom of the motor mounting plate, butdo not tighten the mounting bolts at this time.21. Set the new motor and motor mounting bracket backonto the unit. See Fig. 10.22. Install four bolts, four flat washers, four new lockwashers and four nuts attaching the motor assemblyto the unit, but do not tighten the mounting bolts atthis time.