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Form 4 Switchboard for Southern Charity Hospital, Invercargill

Clive Wilson Switchboards designed, manufactured, and installed the main switchboard (MSB) and distribution sub-boards for the Southern Charity Hospital in Invercargill — Southland’s first free community hospital. Built to AS/NZS 61439 with Form 4 internal segregation, the MSB provides safe, reliable power distribution across the entire facility. Every hour of workshop labour was donated by the Clive Wilson Switchboards team, and all materials were supplied at cost — our contribution to a community-driven project that now delivers free healthcare to patients across the Southern region.

Home › Case Studies › Southern Charity Hospital
Healthcare • Community • 2021 • Invercargill

Project Overview

ClientSouthern Charity Hospital Trust, Invercargill
Year Completed2021
ScopeMain Switchboard (MSB) and distribution sub-boards
MSB SpecificationAS/NZS 61439 Form 4 internal segregation
StandardAS/NZS 61439-1 and AS/NZS 61439-2
ContributionAll labour donated; materials supplied at cost
SectorHealthcare / Community
LocationInvercargill, Southland, New Zealand

The Southern Charity Hospital Trust – A Community-Built Healthcare Facility

Southern Charity Hospital logo

The Southern Charity Hospital Trust was established following the campaign of Winton man Blair Vining, who was diagnosed with terminal bowel cancer in 2018. After discovering how access to healthcare in New Zealand depended on where you lived, Blair dedicated his final years to fighting for equity in the southern region’s health system.

The result is the Southern Charity Hospital – a facility founded by the community, for the community. It provides free healthcare to people across the Health New Zealand Southern region who cannot access treatment through the public or private systems.

The hospital opened on 28 February 2025. Construction began in 2021. The Trust needed a complete electrical distribution solution built to a clinical standard, without drawing on donated funds that should go directly to patient care.

Switchboard Challenges for a Community Hospital Build

Electrical switchboard design for healthcare facilities in New Zealand must account for requirements that go well beyond a standard commercial building. Hospitals require automatic generator changeover with minimal transfer times, dedicated circuits for life-safety and medical equipment, and strict compliance with AS/NZS 3003 (the electrical installations standard for patient care areas).

The Southern Charity Hospital also needed to be delivered within a tight construction programme, coordinating switchboard delivery with the building contractor’s fit-out schedule. As a community-funded project, cost control was critical – but the specification could not be compromised. The electrical infrastructure had to meet the same standards as any publicly funded hospital in New Zealand.

Healthcare facilities place demands on electrical distribution that most commercial builds do not. The main switchboard needed to handle medical equipment, HVAC, lighting, and essential services simultaneously – with the fault isolation and circuit segregation expected in a clinical environment.

At the same time, every dollar saved on construction is a dollar available for patient care. The brief was to deliver a specification well above the minimum required, supply materials at cost, and donate the labour.

Southern Charity Hospital switchboard

Southern Charity Hospital MSB and distribution boards

What Clive Wilson Switchboards Designed and Manufactured

Southern Charity Hospital – Form 4 MSB, generator changeover, power monitoring, and distribution sub-boards.

Main Switchboard (MSB) – AS/NZS 61439 Form 4 Compliant

The MSB was designed and manufactured to AS/NZS 61439-1 and AS/NZS 61439-2 with Form 4 internal segregation – the highest level of internal separation available under the standard. Form 4 provides full isolation between busbars and every functional unit, meaning individual circuits can be isolated and worked on safely without de-energising the rest of the board.

For a healthcare facility where surgical operations, diagnostic imaging, and life-safety systems cannot tolerate unplanned power interruptions, Form 4 is the correct specification. The MSB is rated at 250A and accommodates 40 circuits across the facility, with top-entry sub-main cable connections to four downstream distribution boards.

Generator Changeover System With UA Controller

The MSB includes an integrated generator changeover system with a UA automatic transfer switch controller. In the event of a mains power failure, the system automatically switches the hospital’s electrical supply to the standby generator – maintaining power to all critical systems including operating theatres, patient monitoring, emergency lighting, and refrigerated storage.

The UA controller manages the transfer sequence, monitors both mains and generator supply status, and handles re-transfer back to mains once normal supply is restored. For a hospital facility, automatic changeover with minimal transfer time is a non-negotiable requirement.

Power Monitoring

The MSB is fitted with power monitoring equipment, giving the hospital’s facilities management team real-time visibility of energy consumption, load profiles, and supply quality across the facility. Power monitoring supports ongoing energy management, helps identify abnormal load conditions early, and provides the data needed for preventive maintenance planning.

Distribution Sub-Boards – AS/NZS 61439 Form 2 Segregation

Four distribution sub-boards were manufactured to AS/NZS 61439 Form 2 segregation for local circuit distribution throughout the hospital. Each sub-board serves a different zone of the facility, distributing power from the MSB to final circuits including lighting, general power, mechanical services, and dedicated medical equipment circuits.

Form 2 segregation provides separation between busbars and functional units – compliant and cost-effective for downstream distribution where the full isolation of Form 4 is not required.

Labour and Materials

All workshop labour was donated by the Clive Wilson Switchboards team. Materials were supplied at cost, zero margin. Every board was factory acceptance tested (FAT) in our workshop before delivery to site. Full circuit schedules, single-line diagrams, and labelling were supplied as part of the documentation package.

Technical Summary

MSB rated at 250A, 40 circuits, AS/NZS 61439-1 and AS/NZS 61439-2, Form 4 internal segregation

Generator changeover system with UA automatic transfer switch controller

Power monitoring for facility energy management and load visibility

Four distribution sub-boards to AS/NZS 61439 Form 2 segregation, top-entry sub-main connections

All assemblies factory acceptance tested (FAT) in our workshop

Full circuit schedules, single-line diagrams, and labelling supplied

Workshop labour 100% donated by Clive Wilson Switchboards staff

Materials supplied at cost

“These AMAZING people from Clive Wilson Switchboard donated their time to build the Southland Charity Hospital’s massive switchboard. Thank you so much for giving of your time and talent. By the community, for the community.”

– Blair Vining’s Epic Journey, Facebook

Outcome – Powering Southland’s Community Hospital

The Southern Charity Hospital opened on 28 February 2025 and is now providing free healthcare to patients across the Health New Zealand Southern region. The Form 4 main switchboard and distribution sub-boards manufactured by Clive Wilson Switchboards are in full service, delivering safe, reliable power distribution throughout the facility.

This project demonstrates Clive Wilson Switchboards’ capability in designing and building AS/NZS 61439-compliant main switchboards for healthcare and critical infrastructure in New Zealand. From hospital electrical switchboards in Invercargill to industrial projects across the country, every board leaves our Hastings workshop fully tested, documented, and built to last.

Southland built the hospital. We built the boards.

Frequently Asked Questions

Form 4 is the highest level of internal separation specified in AS/NZS 61439. It requires full separation between busbars, between functional units, and between functional units and busbars. Any individual circuit can be isolated and worked on safely without affecting adjacent circuits or de-energising the rest of the assembly. Form 4 is commonly specified for hospitals, data centres, and facilities where continuous operation and safe maintenance access are critical.

Form 2 provides separation between busbars and functional units but does not require separation between individual functional units. Form 4 provides full separation between all internal components. Form 4 gives greater fault containment and allows safer live working on adjacent circuits. Form 2 is a cost-effective compliant solution for downstream distribution boards where full Form 4 separation is not required.

Yes. Clive Wilson Switchboards manufactures LV switchboards and distribution boards for healthcare, industrial, commercial, and infrastructure applications across New Zealand. All assemblies are manufactured to AS/NZS 61439 in our Invercargill workshop and can be specified to Form 1 through Form 4 segregation.

All switchboards are designed, manufactured, and factory acceptance tested at 33 Clyde Street, Invercargill, Southland, New Zealand. We deliver switchboard projects nationwide.

Need a Switchboard for Your Next Healthcare or Community Project?

Clive Wilson Switchboards manufactures main switchboards, distribution boards, and motor control centres to AS/NZS 61439 for projects across New Zealand — from hospitals and community facilities to dairy plants and water treatment infrastructure.

Whether you need a Form 4 MSB for a healthcare facility or a complete electrical assembly package for infrastructure, our Hastings-based team can help.

Contact us to discuss your project requirements.