The challenge of building portable switchrooms

Building a portable switchroom is no simple task. Given the electrical infrastructure they house, switchrooms must comply with a range of safety standards — something that is further complicated when a switchroom also needs to be easily moved from site to site.

When looking for a solution that could deliver a standards-compliant, safe and portable switchroom for its major projects across the country, a leading Australian electrical company turned to Modulate Group.

Modulate manufactures customised containerised buildings at its 20,000 m² production facility in Mayfield, near Newcastle, NSW, where production and customisation to different needs are handled in-house.

Working together with the electrical company, Modulate created a fully sealed containerised switchroom that can be moved to different sites as required. The customised switchroom houses a motor control centre, variable speed drive, distribution board, transformer, local control station, fire indication panel and remote switching panel.

“Electrical switchrooms are some of the more complex containerised buildings we manufacture. We make sure they meet strict AS3000 standards, other relevant safety standards and any client-specific requirements,” said Jack Adams, General Manager at Modulate.

“The customer placed a high importance on safety and quality from the start, and they were clear with their requirements. Not only did they want to meet all relevant standards, but they wanted to maximise internal space, which is an area where Modulate sets itself apart from other portable offices,” he added.

Fully sealed to keep out dust and moisture, the electrical switchroom could be temperature controlled through three air-conditioning units integrated into the roof to save internal space.

“Two units will be operating, and the third is a backup in case one of the others fails. The system will be set up to maintain an overall temperature of below 25°C, with a calculated heat load of 20.432 kW,” Adams said.

Safety and standards compliance

Modulate containerised buildings, configured from standard 20, 30 and 40 ft (approx 6, 9 and 12 m) container templates, are cyclone-rated structures with a design life of 25 years under heavy use.

The switchroom’s safety features included:

• an emergency push-bar door, for a quick exit — a requirement for all switchrooms;
• a larger-size, fire-rated door (2.3 m high and 1 m wide);
• as a second exit, the original shipping container’s exit (on the opposite side of the switchroom to the main door) with a push bar added;
• a full fire-detection system and fire extinguishers;
• fireproof flooring made from compressed fibre cement;
• emergency exit lights for additional visibility; and
• a recess to maintain optimal canal bend limits for safety and optimised cable efficiency.
   

“Due to the nature of switchrooms, with electrical equipment, heat and high voltages, these extra features mean that it is fully standards-compliant, and the customer can meet their duty of care to employees and visitors that enter the portable building,” Adams said.

Controlling the internal environment

To help keep the internal space free of dust, debris and moisture, a pressurisation fan was installed. The pressurisation fan and the air-conditioning units are all interlocked with the fire detection system, and will automatically shut down in the event of an alarm.

“A skillion roof allowed us to embed components that were essentially hidden within the roof cavity, thereby maximising space inside the switchroom,” Adams said.

“All of the doors are insulated, lined and sealed for a true pressurised space, meeting one of the customer’s key requirements.”

The custom-built portable containerised switchroom is one of hundreds of buildings that Modulate creates, including site offices, ablution units, workshops, storage rooms, lunchrooms, bathrooms, cafes and other customised options for industries such as mining, energy, infrastructure, construction, government projects, defence, and water and power utilities.

Images courtesy of Modulate Group.