A fluctuating voltage supply is detrimental to a refrigerator motor, but not a ceiling fan motor, although both are single-phase induction motors because, the refrigerator motor
1
Is made more robust than the fan motor
2
Is subjected to short duty cycle but the fan motor is subjected to continuous duty
3
Is enclosed in a sealed unit while the fan motor is open to the environment
4
Load is constant, but the fan motor load is voltage dependent.