🔍 Key Concepts

• Overcurrent protection and what happens when too much current flows in a wire • How circuit breakers and fuses work to protect wiring and equipment • How thermal protectors / overload relays protect electric motors and machinery from overheating

💭 Think About

• Ask yourself: does device I (circuit breakers and fuses) respond to excessive current, temperature, or both? • Ask yourself: does device II (thermal protectors / overload relays) act when the load (like a motor) overheats or only when there is a short circuit? • Consider if both types of devices are recognized methods of preventing overheating and damage in electrical circuits and equipment.

✅ Before You Answer

• Verify whether overcurrent protection (breakers/fuses) is a standard method for preventing conductor overheating. • Verify whether thermal overload relays are commonly installed on motors to prevent overheating due to overload conditions. • Confirm that the question asks about protecting against overheating, not just short circuits or ground faults.