What a safety switch actually does
Most people know they’re supposed to have safety switches but aren’t clear on what they actually do. A safety switch - technically an RCD (residual current device) - continuously monitors the balance of current flowing out and back through a circuit. If it detects that current is finding a path to earth (through a person, for example), it cuts power in 30 milliseconds or less. That’s fast enough to prevent electrocution in most scenarios.
Circuit breakers don’t do this. They protect the wiring from overloads and short circuits, which is important but different. A circuit breaker will not save you from a shock - only an RCD will.
The gap in older homes
Homes built before the late 1990s often have circuit breakers on every circuit but safety switches on none, or only on the power circuits added later. This is still legal in existing installations that haven’t been modified - but it means a fault on a lighting circuit, for example, has no RCD protection.
The practical solution depends on the switchboard. Some older boards can have RCDs added. Others are better replaced outright, particularly if they’re also old enough that replacement parts aren’t readily available. Ed will assess the board and give you a clear recommendation rather than defaulting to the most expensive option.
RCDs versus RCBOs - what’s the difference
An RCD protects a group of circuits - you can have one RCD protecting all power circuits, for example. An RCBO combines the functions of an RCD and a circuit breaker in a single device, protecting one circuit at a time. The advantage of RCBOs is that a fault on one circuit trips only that circuit rather than all circuits on the shared RCD.
For modern switchboard upgrades, RCBOs on individual circuits are generally preferred because they reduce nuisance tripping. The right choice depends on the board layout and what you’re trying to achieve.
Rental properties and safety obligations
Landlords have obligations around the safety of the electrical installation in a rental property. Safety switches on power circuits are considered standard for rental properties - their absence creates liability exposure. Ed can assess the switchboard at a rental, identify what protection is in place, and provide documentation of any additions made.
Related next steps often include Electrical Safety Inspections Central Coast and Fault Finding Electrician Central Coast . If you are comparing local coverage as well, start with Electrician in Erina NSW or Electrician in Gosford NSW .