Final answer:
True, electrical appliances must have a means to safely disconnect from the power source to allow maintenance, prevent thermal hazards, and protect against electrical shocks. This is often facilitated by safety features such as the three-wire system, circuit breakers, fuses, and Ground Fault Circuit Interrupters (GFCI).
Step-by-step explanation:
The statement that 'All electrical appliances are required to have a disconnecting means' is generally true. Electrical safety regulations typically require that electrical appliances have a way to disconnect them from their power source. This serves multiple safety purposes, such as allowing for safe maintenance, preventing thermal hazards, and protecting against electrical shocks.
Most appliances are connected to the power source using a three-wire system, which includes a live/hot wire, neutral wire, and an earth/ground wire. The earth/ground wire serves to ground the appliance, reducing the risk of shock hazards. Additionally, the neutral wire may be grounded at the voltage source and user location. Electrical safety devices such as circuit breakers and fuses are in place to interrupt excessive currents, also serving as a form of disconnecting means by protecting against thermal overload.
More advanced safety systems, like Ground Fault Circuit Interrupters (GFCI), are designed to prevent electrical shock by detecting the loss of current to unintentional paths and immediately disconnecting the circuit. These systems are essential not only for compliance with electrical codes but for user safety.