[Reporter Su Meng-juan / Taichung report] Yesterday, the Taichung Green Line of the MRT experienced abnormal braking of a train which could not move, and the faulty train was taken to the workshop of the Taichung MRT and checked and repaired overnight. It was judged that the abnormality was caused by the electromagnetic valve of the parking brake in the carriage, which caused the circuit breaker to trip. This is the first time this type of failure has occurred on the Taichung Green Line. The Taichung MRT company stated that in addition to adding regular inspection items in response to this abnormal event, this item will also be included in periodic inspection items in the future. In addition, the Taichung MRT will also review the fault elimination procedures and improve the maintenance procedures.
The Taichung Green Line train set 01/02 was unable to move due to abnormal braking at the Taichung HSR Station yesterday. The faulty train was dispatched to the end of the track and parked, allowing the system to resume normal operations. It was sent back to the Beitun depot for inspection and repair in the early hours of today. The system is still under warranty. The deputy general manager of the Taichung MRT company, Yeh Chin-tsai, personally led the team with personnel from the North Metropolitan Bureau and Kawasaki Heavy Industries to inspect the train overnight, and confirmed the cause of the fault was the coil failure of the parking brake solenoid valve of car 01, which caused the power-end control circuit breaker to trip due to overload at 4 a.m.
The Taichung MRT company stated that this abnormal event was the first case of a parking brake solenoid valve failure causing a circuit breaker to trip. The abnormal component has been further analyzed by the manufacturer to determine the cause of the fault. In order to ensure the proper functioning of the system equipment, this abnormal event will be discussed with the manufacturer and included in the periodic inspection items.
The Taichung MRT company explained that during daily routine inspections, they will check whether the brake system function is operating normally and whether there are any abnormal warning signals in the train management system (TMS) monitoring screen. However, the original manual does not have specific inspection or measurement items for the solenoid valve. This abnormality was caused by a sudden failure of the solenoid valve. Therefore, the company will discuss with the manufacturer to establish a routine measurement record to detect early warning signs of failure.
The Taichung MRT company deeply apologizes to passengers affected by yesterday’s journey. Through this event, the company has reviewed and improved the fault elimination procedures and maintenance procedures. In addition, the parking brake solenoid valve of train set 01/02 has been replaced with a new one, and will undergo a 100-kilometer test run on the testing track today. After the test, it will be checked and, if normal, will return to passenger service.
