The power outage in Parliament was caused as the substation responsible for supplying electricity failed to adjust to the low voltage, according to inquiries opened over the incident.
The power cut for more than three hours in the parliament building halted the ongoing session.
The outage struck the building at 4.45pm on Tuesday, leaving most of the blocks without electricity.
The House relied on back-up generators to keep the session alive before it was adjourned for the day.
Four separate inquiries were opened by the Power Division, Dhaka Power Distribution Company (DPDC), Bangladesh Power Development Board (PDB) and Power Grid Company of Bangladesh (PGCB).
According to the findings, filed with the power ministry on Wednesday, there were no glitches with the transmission, but the substation failed to respond to the low voltage, which triggered the back-up generators to go online.
The DPDC report said that the substation at the Parliament premises didn’t have a number of parameters coordinated, including load of electricity being supplied and system voltage.
The time interval for breakers in case of low voltage was not specified, it added, causing the outage.
According to current arrangement for power supply to the House, the second source from DPDC’s Asad Gate 33/11 KV feeder will automatically go online if the primary source from PWD’s Khejurbagan 33/11 KV falters. A third source from DPDC’s Mogbazar 33/11 KV feeder is set to ensure supply through auto-change over-switch.
In case all of the three sources trip, a fourth source from DPDC’s Kawran Bazar 33/11 KV feeder can be invoked manually.
The PGCB report echoed saying there were no issues with the electricity transmission and blamed the substation’s glitch.
“Our investigations found no problems in our system on Tuesday. The power supply did not trip anywhere. The same system is used for supplying power to the Bangabhaban and the Ganabhaban. There were no problems there. So we think it’s the parliament substation,” PGCB Chief Engineer (Transmission-1) Md Rafiqul Islam Chowhdury, who headed the inquiry, said.
The DPDC made six recommendations, including setting up of generators in line with the power supply load and activating automatic voltage regulator (AVR) at the Khejurbagan power feeder.
It also alleged that the Public Works Department, which was responsible for setting up the parliament substation, did not include anyone from the DPDC in the procurement process.
DPDC Executive Director Engineer Ramiz Uddin Sarkar said, “The PWD installed it themselves. They didn’t inform us. We were not even in the committee.”
“We supply electricity at 11 KV from 33 KV to the Parliament. The substation is the PWD’s authority,” he added.
The Bangladesh Power Development Board (BPDB) said that production at the 440 MW power plant on the banks of Meghna and the Ghorashal 100 MW plant halted Tuesday afternoon.
The halt created a shortage of 500MW power to the national grid, which however, did not trip the PGCB transmission lines but caused a low voltage.