Check all electrical connections, tighten as necessary
Inspect all contactors and relays, replace as necessary
Check accuracy of thermistors, replace if greater than ± 2° F (1.2° C) variance from calibrated thermometer.
Check accuracy of transducers, replace if greater than ± 5 psig (35 kPa) variance from calibrated gage.
Obtain and test an oil sample. Change oil only if necessary.
Check refrigerant filter driers for excessive pressure drop, replace as necessary.
Check condition of condenser fan blades and ensure they are securely fastened to the motor shaft.
Perform service test to confirm operation of all components.
If the unit is equipped with a UPC, check the battery and replace if necessary.
If the unit is equipped with a ground fault interrupterconvenience outlet, GFI-CO (208/230, 460, or 575-3-60 only), test the operation of the device. Replace if necessary.
Source: Carrier (www.shareddocs.com)