Home · Services · Safety switches (RCDs)
An RCD trips in milliseconds if current starts flowing where it shouldn't — through a drill, a frayed cable, or your hand. If any circuit in your home doesn't have one, you're rolling dice. From $260 per circuit, estimate online.
What it is
A circuit breaker protects the wiring from overload. It stops your house burning down. An RCD (Residual Current Device) protects you. It detects tiny imbalances — milliamps — and cuts power fast enough to prevent electrocution. You need both.
Under AS/NZS 3000, every final subcircuit in a new or upgraded installation must have RCD protection — that's power and lighting circuits. Older homes aren't legally forced to retrofit, but they should be. A safety switch costs $260. A trip to the ICU costs everything.
Signs you don't have enough
RCDs have a small test button (often labelled T or TEST). If your board has only rocker-style breakers, it probably has no RCD protection at all.
Common in pre-2000 homes. Technically compliant at the time but means a single fault takes out your entire house — including the fridge. Modern best practice is one RCD per circuit.
Many older homes have RCDs on power points only. Lights were assumed "safe." But you change a bulb, drop something, touch a live wire — same risk. RCD the lighting too.
Wet environments = higher electrocution risk. RCDs on these are non-negotiable. If you've got outdoor power without one, sort it this week.
What it costs
From $260 for the first circuit protected, $160 per additional circuit (gear + labour). Most Sydney homes need 2–4 new RCDs added — total job typically $420–$750. If your board's tight on space and needs an extension, add ~$380.
Takes 1–2 hours. No mess. CCEW issued on every job. If multiple circuits need doing, it's often cheaper per unit — build a quote and see.
RCD FAQ
Sometimes. Old fridges, old dishwashers, damp circuits — they leak enough current to trip a sensitive RCD. That's the RCD doing its job, not malfunctioning. I test every circuit after install. If something's leaking, I trace it and fix it — not bypass the safety device.
Push the test button every 3 months. Takes 5 seconds. That's all. If the test button doesn't trip it, the RCD is failed and needs replacing.
AS/NZS 3000 requires separate RCDs per final subcircuit on new installations. On older homes being retrofitted, one master RCD is better than nothing but one-per-circuit is best practice. I'll recommend per your specific board.
Usually yes, if there's space. If your board is full of ceramic fuses or older breakers, I'll often recommend the full upgrade — RCDs alone can't be fitted to some boards. I'll tell you honestly which path saves you money long-term.
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