KARACHI, July 7: Power failures continued unabated on Sunday as the Karachi Electric Supply Corporation grappled with power breakdowns.

KESC consumers phoned Dawn to lodge their complaints against the power utility and protested the inability of the power utility to prevent power breakdowns from occurring and removing the faults promptly.

Gulshan-i-Iqbal residents told Dawn that their ordeal had not yet finished, as the power breakdown that had started some days back continued intermittently on Sunday.

A resident of North Nazimabad, Block A, said it was beyond his comprehension why so many cable faults occurred at the same time in different parts of the city. “On Saturday KESC officials told Gulshan-i-Iqbal’s consumers that because of a cable fault the power supply had been interrupted. In my area the power supply remained now-on and now-off because of the same cable fault. How long does the KESC take to rectify a cable fault?” he wondered.

A KESC official told Dawn that complaint centres were tasked to remove at least six types of faults: fluctuation/high voltage, one phase missing, meter burnt, fire case, service cable fault, and public lights complaints.

He explained that service cable faults were experienced due to the following reasons: excess load of the consumer, load of the consumer not equally distributed to all the three phases, and damage to the cable done during digging by some civic agency.

“In all types of service cable faults, the supply to the consumer is temporarily restored by providing overhead connection and then the complaint note is forwarded to the underground cable maintenance department.”

He added that a lot of consumers complained about fluctuation/high voltage during summers on low-tension networks (400 volts). “Fluctuation/high voltage is mostly caused by the discontinuity of neutral. In a three-phase system load is connected to a Y configuration in which neutral is grounded. Whenever there is loss of continuity at any point in the circuit, the neutral voltage acquires a potential and starts floating.”

He added that fluctuation/high voltage occurred mostly when consumer load was not connected in balance to all the three phases. “Most of the equipment is connected to one phase while the other phases are either free or lightly loaded. This causes unbalanced current to flow through neutral jumpers which finally burns causing high voltage/ fluctuation.”

The KESC official added that theft of neutral conductors from overhead lines and neutral leads from the KESC sub-stations also caused high voltage/fluctuation.

Calling from Kharadar, a resident said that recently people of his locality had put up a lot of illuminations to celebrate a religious festival.

Calling from Federal B. Area, Block 8, a resident said his locality had been without electricity for some time earlier in the day.