Abstract: An overcurrent relay comprises a housing having an external portion, an overcurrent responsive mechanism, disposed within the housing, for opening or closing a pair of contacts in response to an overcurrent, an adjusting screw device for adjusting the operating current of the overcurrent responsive mechanism, the adjusting screw device being rotatably supported by the housing and having serrations on the periphery thereof, and an engaging member mounted on the external portion of the housing for engaging with a serration of the adjusting screw device for preventing an unintentional rotation of the adjusting screw device.

Abstract: Series circuits consisting of diodes for blocking reverse currents are inserted between the upper and lower arms of bridge-connected transistors constituting an inverter, and contacts of a contactor adapted to close upon a stoppage of power supply are respectively connected in parallel with the series circuits so as to short-circuit the series circuits of the diodes, whereby the inverter is changed-over from a current type inverter to a voltage type inverter upon the stoppage of the power supply. Thus, even in an elevator employing the current type inverter, a rescue operation during the stoppage of the power supply can be performed with a simple circuit arrangement employing a D.C. power source.