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6.6 kV Switchgear Replacement Project

PWCS 6.6kV Switchgear Replacement Project

Background and Project Summary

Port Waratah Coal Services (PWCS) operates a large coal handling facility in Newcastle, NSW. Over the past several years, it has undertaken a rolling program of replacing aging 6.6kV switchgear throughout it's Kooragang site, including original switchrooms constructed in the 1970’s.

The new switchgear chosen for installation was ‘ABB’ UniGear ZS1, 550 and ZVC switchgear. To date, five switchboards have been replaced over an eight-year period, ranging in size from 2 to 8 panels, with the sixth and final switchboard planned for installation in late 2021.



Figure 1 - Typical Legacy Switchgear 


Project Execution

PCE has worked closely with PWCS for many years as a trusted HV engineering partner. As such we were engaged to provide electrical engineering and technical support for the Kooragang 6.6kV Switchgear Replacement Project.

This initially included feasibility investigations of possible OEM switchboard suppliers to ensure the most suitable switchgear was selected as the replacement. The selected ABB equipment was chosen due to its robustness, proven reliability, cost effectiveness and ability to supply narrow footprint, fully withdrawable air insulated switchgear with its ZVC range of feeder modules.

PCE were responsible for, and successfully completed:

  • Preparation of the technical specification documents for supply of switchgear;
  • Preparation of the technical specification documents for installation of switchgear during dedicated and tightly controlled shutdown periods ranging from 3-5 days;
  • Working with ABB and PWCS, then approving all electrical schematics and other new drawings required for removal and replacement of the switchgear;
  • Technical advice with regard to lengthening and/or re-terminating the existing paper lead insulated and XLPE 11/6.6kV cabling to the new switchboard cubicles;
  • Preparation of protection reports and Arc Flash studies for each location;
  • Programming the ABB REF/REM protection relay files including arc flash detection logic, Modbus communications via fibre/Ethernet;
  • Onsite Commissioning, Installation and Testing Plans, plus commissioning and general assistance during the switchroom outages;
  • Carrying out on-line Partial Discharge testing on the new switchboards and cables to ensure new equipment and 6.6kV terminations showed no early singes of insulation damage or failure.


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Figure 2 - Typical Replacement Switchgear


Project Challenges

This PWCS site has been in operation for over 40 years, which has led to a mixture of equipment, cables, network communication and control philosophy (including latest conveyor safety codes) throughout the switchrooms. The new equipment had to be adaptable to all these situations, as well as adopting the latest HV equipment safety designs, such as arc blast venting and arc detection that will trip a fault supplied feeder in milliseconds. Remote switching stations were also installed that removed the Authorised Switchgear Operator form harm’s way in the event of a fault occurring during switching.

Another major challenge was obtaining suitable time frames for outages to enable the old switchgear to be removed, new to be installed, HV/LV cables and comms to be connected, testing and commissioning. These outages, and the associated switchgear replacements, had a direct impact on the coal delivery schedule for PWCS, who is the major contributor to this, Australia’s largest coal export terminal.

Looking Forward

PCE is proud to be a major contributor to the design and implementation of the PWCS Kooragang 6.6kV Switchgear Replacement Project. As this project comes to a close, PCE is excited to assist PWCS with a similar HV switchgear conversion project for its Carrington site; containing a further eight switchrooms of varying switchgear models / vintages, control systems and design challenges.