If the protective device, such as a fuse or circuit breaker, fails to operate as expected (fuse doesn't open or circuit breaker doesn't trip), it can have several potential consequences for the electrical appliance:
Overheating: The protective device is designed to interrupt the electrical circuit when the current exceeds a safe level. If it fails to do so, the excessive current flowing through the circuit can lead to overheating of the appliance's components. Prolonged overheating can cause damage to the internal wiring, insulation, and other sensitive electronic components, which may result in reduced performance or even total failure of the appliance.
Fire Hazard: An electrical appliance that experiences a sustained current overload due to a failed protective device can become a fire hazard. Overheating can lead to ignition of flammable materials inside the appliance or nearby objects, potentially causing a fire.
Short Circuit Damage: In some cases, the protective device's failure may lead to a short circuit. A short circuit occurs when two conductors that are not supposed to be in contact touch each other, creating a low-resistance path for current flow. This can cause a significant increase in current, leading to rapid overheating and possible damage to the appliance.
Electrical Shock Hazard: In situations where the protective device fails and the fault occurs in the appliance's external casing or conductive parts, there is an increased risk of electrical shock to users who come into contact with the appliance.
In summary, if the protective device fails to operate as expected and doesn't interrupt the circuit when an electrical fault occurs, the appliance may experience various degrees of damage, ranging from reduced performance to complete failure, electrical fires, or posing a danger to users due to electrical shock hazards. It's crucial to regularly check and maintain the protective devices in electrical circuits to ensure they function correctly and provide the necessary protection against electrical faults. If you encounter any issues with your electrical appliances or protective devices, it's best to seek assistance from a qualified electrician to diagnose and rectify the problem safely.