| 摘要 |
PROBLEM TO BE SOLVED: To provide a fault diagnosing device which can appropriately inform the user of the device of faults by dividing the main causes of the faults into temporary causes and steady causes by means of smaller numbers of detecting means and signals. SOLUTION: When the overcurrent detecting section 11a or voltage-drop detecting section 11b of an abnormality detecting section 11 detects the abnormal drive of a power transistor 10 and outputs a signal, a control section 7 stops the power supply to the transistor 10 by temporarily turning off an outdoor power source 9a through an outdoor control section 7a. The section 7 discriminates the occurrence of an overcurrent when the signal from the abnormality detecting section 11 is discontinued immediately after the transistor 10 is stopped or a voltage drop when the signal from the section 11 is continuously outputted at a prescribed voltage level or higher. Each of an overcurrent discriminating counter 12 and a voltage-drop discriminating counter 13 counts the number of continuing times of fault discrimination. When the count values of the counters 12 and 13 reaches prescribed values, the control section 7 discriminates that the main cause of the fault is a steady cause, such as the breakage of the transistor 10, breakdown of the parts of a power supplying voltage circuit, etc., and informs the user of the cause. |
