McKay and MGE played a key role in the upgrade of the Clarks Beach Wastewater Treatment Plant, delivering critical electrical infrastructure to support the plant’s advanced treatment systems.
At McKay’s Hamilton branch, two fully containerised switchgear cabins were prepared over a six-week fitout. They were then integrated with MGE switchboards and programmable logic controller (PLC) cabinets before being transported to site and connected to the plant’s electrical systems. Together, the cabins act as the plant’s engine room, powering critical systems that treat and manage wastewater for the growing Clarks Beach community. This infrastructure forms part of the plant’s upgraded treatment capabilities, allowing it to treat more than five million litres of wastewater a day to a high environmental standard. The work completed by McKay and MGE ensured that all electrical and mechanical systems were ready for cold commissioning, setting the stage for the plant’s eventual full operation.
Project deliverables
The project centred on two custom-built, 40-foot containers prepared at McKay’s Hamilton branch and purpose-designed to serve as switchboard rooms at the Clarks Beach plant.
- Container fit-out: Each container was fitted with new exit doors installed to Watercare standards and compliant with AS/NZS 3000:2007. The walls were lined with poly panelling for thermal and acoustic insulation, the floors were reinforced to support the weight of the switchboards, and internal lighting, including emergency fittings, was installed throughout.
- Switchboard manufacturing: Switchboards were built by MGE – McKay’s group switchboard manufacturing company – as MGE NZ Powerak boards. They included main switchboards (MSBs), motor control centres (MCCs), PLC cabinets, and distribution boards (DBs), all manufactured to Watercare standards. The flexibility of the Powerak design was critical, allowing the MGE team to design boards specifically to fit within the two containers.
- Power distribution: The main switchboard distributes power to two process switchboards, which monitor and control all motor-driven equipment across the plant.
- Control systems: Multiple PLC cabinets were installed to coordinate and control all plant processes, forming the core of the facility’s operational control system.
- Cable containment and support: Cable ladder containment was installed inside the containers to provide appropriate support for the wiring systems and safe access throughout the switchboard rooms.
- Energy efficiency and resilience: Variable-speed drives were incorporated to optimise motor control and reduce energy consumption. An uninterruptible power supply (UPS) system was also installed to ensure that critical instruments and equipment remained operational during any power outages.
Our approach
This project presented a notable logistical challenge worth highlighting. Installing the switchboards required a multi-person team to carefully lift and manoeuvre each unit into the containers before securely anchoring and bracing them for transport. The containers were then moved to site using a swinglift sideloader, and a 100-tonne crane was used to lift and position each unit onto its final supporting structure. The off-site prefabrication approach at McKay’s Hamilton branch was key to streamlining the on-site installation and keeping the project on programme.
