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Projects Changi-Airport power-turn-on-inspection-socials
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22kV Network System for Changi Airport

Projects Changi-Airport switchroom-1

Supplying a 22kV network system to support the development of a new passenger terminal (T5) at Singapore’s Changi Airport.


Voted as the world’s number one airport for the previous eight years, Singapore’s Changi Airport is one of the largest in the world.

Located at the eastern end of the island nation, the airport occupies 13 square kilometres of ground and services over 68.3 million passengers a year.

A new passenger terminal (T5) was under development to enhance the airport’s capacity to meet future growth. The T5 terminal was set to be one of the world’s largest airport terminals and was part of a wider plan for Changi East development, which included the development of a three-runway system and network of inter and intra terminal tunnels. These tunnels would allow for convenient movement of baggage, passengers and air side vehicles.


Ampcontrol was contracted to design, supply, deliver, install, test and commission the 22kV network system, including the following:

• Engineering and design, including power studies for the entire temporary electrical reticulation works.

• Supply to surface ancillaries and 3x tunnel boring machines including high voltage cables and couplers.

• Testing and commissioning of the 22kV power system including the 3 tunnel boring machines.

• Licensed electrical worker services including monthly inspections, yearly and half yearly maintenance and testing.

As this was the first large diameter bored tunnel in Singapore, the power requirements were much more than the previous projects completed in the country.

A 22/22kV isolation transformer was used to supply the tunnel boring machine to limit the secondary fault current to the system. Additional protection was also implemented due to the transformer size.

This design and approach were both safer and more practical than using a 11kV system.


The site supply was successfully powered on 7 October 2021. The project is still ongoing.

Some of the successful outcomes of this project included:

  • Delivering through the Covid-19 pandemic.
  • Site PM and construction supervisor were sent for courses (SDO and SMO) to manage the site in a safe manner.

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