Kiunga Power Station, PNG – 11 kV switchboard audit

Client: Ok Tedi Mining Limited
Location: Kiunga, Papua New Guinea
Date: September 2014 – November 2014

Identifying workable and cost-effective options to upgrade a power station’s electrical infrastructure to meet increasing demand.


The Ok Tedi copper and gold mine is a major contributor to Papua New Guinea’s economy. The expansion of the port town of Kiunga, which services the mine, was requiring more power than Ok Tedi’s Kiunga Power Station could provide.

Entura was engaged to audit the power station’s main 11 kV switchboard and connected infrastructure, including the outgoing 11 kV township cable, to determine the capacity and/or limitations of the existing power infrastructure, and the capacity for additional generation.


Entura collected data on the existing switchboard, circuit breakers, current transformers and voltage transformers, and completed a pre-site-visit desktop study. Prior to the site audit, Entura met with Ok Tedi representatives to clarify the focus of the audit and the client’s goals and expectations.

A site inspection was performed at the power station, which included visually inspecting the switchboard (including racking out CBs, and taking bus bar, VT and cable box covers off) and associated infrastructure (including feeder transformers, generators, 11 kV and 415 V electrical feeds).

The existing fault level and capacity for additional generation were calculated. Entura demonstrated that the existing 11 kV switchboard bus had significant electrical capacity for adding more generation and load. We also identified that the 11 kV township cable appeared to be overheating, leading to plans for its replacement.

A detailed audit report was prepared including condition assessment and single line diagrams for various options to upgrade the power station.


Entura investigated several potential options through which the client could achieve its primary goal, including doing nothing, adding more generation, installing a new switchboard, constructing a new switchroom, and adding renewable energy.

Entura’s practical, real-world experience of electrical asset management enriched these investigations by incorporating consideration of important variables such as reliability, availability, capacity, efficiency, security,  longevity, cost-effectiveness, simplicity and timeliness – enabling the client to select the most appropriate solution for their particular situation and priorities.