To provide an overcurrent protective device capable of coping with cases of various reverse operating temperature and various overcurrent by changing types of bimetal and wire sizes of a heater since a movable contact is forcibly removed from a fixed contact by melting a thermofused metal with heat generation of the heater when the contact for opening a current conduction circuit to an electric motor at the time of overcurrent and preventing burnout is welded.

The overcurrent protective device 1 is provided with a first overcurrent relay 2 having the first bimetal contact piece which intercepts a current supply circuit at first temperature or above and returns at temperature lower than the first temperature and higher than 0C, and a second overcurrent relay 3 having a second bimetal contact piece which is connected in series with the first overcurrent relay and intercepts the current supply circuit to an electric compressor at second temperature or above higher than the first temperature and returns only at temperature lower than 0C. An amount of heat generation of the first electric heater is set up to be greater than an amount of heat generation of the second electric heater so as to make an operating time of the second bimetal contact piece longer than an operating time of the first bimetal contact piece.