KUALA SELANGOR, Dec 19 — Tenaga Nasional Bhd (TNB) today said the maintenance work at the Bukit Badong substation is proceeding as scheduled.

The electrical maintenance which is causing water disruptions in the Klang Valley is expected to be completed by midnight, The Star Online reported TNB chief engineer (operations and maintenance) Ishak Muhammad Zain as saying.

"60 per cent of the maintenance work is completed as at 3pm and it is expected to be fully completed by midnight,” Ishak was quoted saying.

He also said it was crucial that the maintenance work was not postponed in order to prevent a flashover, which will result in a longer period of shutdown in the future.

The maintenance work has resulted in the shutdown of the substation from 8am with 120 staff involved.