The invention concerns a device for localizing a closing fault in landing doors equipped with locks that are electrically connected series.
The localizing device includes a number of electric impedances (R
. . . R
) respectively mounted in parallel with said locks (
. . . 12
), measuring devices (
) for measuring the total impedance of the safety chain, microprocessor (
) which allow to compare said measured impedance with a cross reference table of floor impedances that provides all the impedance values of the safety chain obtained by opening one or the other of the landing doors, and display (
) which show the floor or floors on which the breakdown occurred.