PURPOSE: To lessen seismic erroneous operation of an oil-containing electric appliance by forming it in such a manner as to vary the pressure detecting direction by all the pressure detecting means.

CONSTITUTION: Pressure-releasing devices 8 and 9 installed on pressure-releasing tubes 6 and 7, respectively, are so designed that their respective directions are shifted by a fixed angle (e.g. 180°) so that pressure detecting devices 10 and 11 can have their respective pressure detecting direction of 22 and 23. Respective relays in the pressure detecting devices 10 and 11 are connected to AND circuit 15. In the case of occurrence of an earthquake, when the pressure detecting device 10 is operated by inertia of oil due to vibration of the pressure-releasing tubes 6 and 7, the pressure detecting device 11 is not operated, so that AND condition to be obtainable from these devices become unable to be obtained, and therefore, it is possible to reduce the seismic erroneous operation in this mechanism.