The switchboard is the heart of your property's electrical system. Every circuit in the building originates here, and every protection device that stands between a wiring fault and a fire lives here. Yet switchboards are routinely the most neglected part of a building's infrastructure — older panels still contain ceramic fuse holders with rewireable fuse wire, semi-enclosed rewirable fuses, or first-generation miniature circuit breakers (MCBs) installed without any residual current protection. A modern switchboard upgrade is not a cosmetic exercise; it is a safety-critical replacement with measurable, quantifiable benefits.
Replacing Ceramic Fuses and Legacy Breakers
Ceramic fuse holders rely on the owner (or a tenant, or a visitor) replacing blown fuses with the correct rating of fuse wire. In practice, fuses are replaced with heavier wire or bypassed with a nail or a coin — creating a circuit with no meaningful overcurrent protection at all. This is a leading cause of insulation fires in older Australian homes and commercial premises. PrismTech removes all rewireable fuse equipment and replaces it with type-tested MCBs or RCBOs, each rated to the current-carrying capacity of the circuit it protects.
First-generation MCBs installed in the 1970s and 1980s were frequently B-curve devices rated to fault currents that no longer match the prospective short-circuit current available at modern supply points. AS/NZS 60898 requires that circuit breakers be coordinated with the available fault level, and aged boards often fail this test. PrismTech verifies the prospective fault current at the main switchboard and specifies replacement breakers with appropriate breaking capacity.
RCBOs — Per-Circuit Protection
A residual current device (RCD) operates by detecting imbalance between the active and neutral conductors of a circuit — the signature of current flowing through a person or through an earth fault. The RCD trips in milliseconds, before the leakage current reaches the threshold associated with ventricular fibrillation (30mA for a Type A RCD, the Australian standard type). Fitting a single RCD across multiple circuits means a fault on any one circuit trips all of them — a nuisance in a home, a serious incident in a commercial kitchen or server room.
PrismTech installs RCBOs (residual current circuit breakers with overcurrent protection) as the default protection device in upgraded switchboards. Each circuit has its own RCBO, providing both earth leakage and overcurrent protection independently. A fault on the oven circuit trips only the oven — the lighting, refrigeration, and security system remain powered. This is the correct engineering approach and is now the baseline expectation in modern Australian electrical practice.
Surge Protection, EV, and Battery Readiness
Transient overvoltages from lightning strikes, utility switching events, and nearby industrial loads routinely reach 2,000V to 6,000V at the point of entry to a building — well above the 230V the installation's components are designed for. AS/NZS 61643.11 defines Type 1, Type 2, and Type 3 surge protection devices (SPDs). PrismTech installs a Type 2 SPD at the main switchboard as standard on all upgrade projects, with a Type 1 available where the building has a direct aerial supply or a separate overhead service. SPDs are non-sacrificial to the switchboard in operation and replace themselves when they reach end-of-life — a status indicated by a visual flag on the device.
- Full switchboard replacement with DIN-rail mounted RCBOs per circuit
- Removal of all ceramic fuse holders, rewireable fuses, and legacy equipment
- Type 2 surge protection device (SPD) installed as standard
- Dedicated circuit and isolator provision for EV charger installation
- Battery system (VPP or home storage) connection infrastructure
- AS/NZS 3000 compliant labelling, circuit schedules, and Certificate of Compliance
What the Upgrade Process Looks Like
Most residential and small commercial switchboard upgrades are completed in a single day. PrismTech arrives with the new enclosure pre-populated with RCBOs sized to the existing circuit schedule, minimising the time the installation is de-energised. We transfer circuits one by one, testing each before reconnecting, and restore power progressively rather than leaving the entire property without electricity for the full duration of the work. A Certificate of Compliance is issued before we leave.
If your switchboard still has ceramic fuses, or if your MCB panel doesn't have residual current protection on every circuit, the risk is real and measurable. Contact PrismTech for a switchboard assessment — we'll tell you exactly what's there, what standard it falls short of, and what a compliant upgrade will cost.
Frequently asked questions
How do I know if my switchboard needs upgrading?
If you have ceramic fuse holders with rewireable fuse wire, a board without RCDs, or a switchboard that can't accommodate a new circuit without overloading a shared RCD, an upgrade is warranted. Age alone is not the only indicator — condition, protection level, and capacity headroom all matter.
Will my power be off all day during the upgrade?
No. PrismTech pre-populates the new enclosure with correctly sized RCBOs before arriving. We transfer circuits progressively, restoring power to each group before moving to the next. Total de-energisation is typically under two hours for a residential board.
What is an RCBO and how is it different from a standard circuit breaker?
An RCBO combines residual current detection (earth leakage protection, 30mA threshold) and overcurrent protection (circuit breaker) in a single device. Unlike a shared RCD covering multiple circuits, each RCBO protects only its own circuit, so a fault on one circuit does not trip others.
Can the new switchboard support an EV charger or home battery system?
Yes. PrismTech includes a dedicated 32A or 40A circuit and isolator for EV charger provision and can install the appropriate breaker and submain cabling for a battery system at the same time as the switchboard upgrade — avoiding a second disconnection event later.