A controller for a refrigerator is provided to prevent a voltage drop in the power supply occuring when AC power is supplied to a large number of air conditioners from the same power source simultaneously such as when a power failure is recovered to normal. The controller comprises a time setting circuit to arbitrarily set the timing of a reset signal applied to a microprocessor (51). A time setting switch to an arbitrary value, the time elapse from the generation of the reset signal to the activation of the compressor (41). According to the setting of the time setting switch, the microprocessor controls the delay time for starting the air conditioner. When the power supply is restored after power failure, it is possible to prevent the air conditioners from restarting simultaneously and thus prevent a voltage drop in the power supply. <IMAGE>
