PURPOSE: To detect surely the defective state of a cable in adaptation to actual operation, by counting welding times, shortcircuiting a welding electrode by a test start signal when the value thereof attains a set value and detecting abnormal current.
CONSTITUTION: When a welding control device operates, a signal for closing a counting switch 5 at every welding is outputted from a generation section 23 for counting signal and a counter is counted up. When the count attains a set value, a test start signal is outputted to a sequence controller 20, by which the pressurization control signal from a welding control device 21 is supplied to a valve section 22 for pressurization. Thereafter the shortcircuiting welding current of a welding electrode attaining a shortcircuiting state is detected with the device 21. When current abnormality arises as a result of flowing the test current thereafter, a pilot lamp for abnormality is lighted; at the same time, an abnormality detection signal is fed to the controller 20, by which the necessary control is accomplished.
NAGAI OSAMU
ONO YOSHIYUKI
