PESHAWAR: A report, submitted to the Khyber Pakhtunkhwa government, has revealed causes behind Peshawar BRT buses’ catching fire.
More people were travelling than the capacity of the bus which created abnormal external conditions and eventually increased pressure on motor controller which led to eruption of fire in capacitor.
“Due to the unexpected abnormal external conditions, which includes multiple parameters, which eventually led to significant increase in ripple current that led to failure of the capacitor to smooth the current as it was beyond the capacity of the capacitors installed in the motor controller.
“The failure of the capacitor directly led to the violent heat up and malfunction, even explosion, which consequently led to short circuit of the high volt power circuit and fire started,” said the report.
It read that the peak current was supposed to be restrained by software upgrade to limit the flow of current from the motor controller change, however, certain electronic components in the motor controller of the buses were checked to have been damaged by the abnormal current before the software updating which caused the accident after the program upgrading.
The report read that according to the site test on Sept 15, the capacitance value of the thin film capacitor had decreased from 350 to 332 whose attenuation reached about 5 percent and the temperature rise was more drastic because of the deviation.
Special Assistant to KP Chief Minister on Information Kamran Bangash said that the government had increased capacity of the buses, while minor faults still existed. He said the bus manufacturing company would replace the parts and not charge extra money as the buses were in warrantee.
He said the BRT service would be restored from Oct 25 onwards.