The device providing overload protection for motors is commonly a thermal ______.

The device providing overload protection for motors is commonly a thermal ______.

• A. Device
• B. Relay
• C. Switch
• D. Controller

Answer: (A)

Overload protection in motors is driven by heat. When a motor draws more current than it can safely handle, the windings heat up, which, if left unchecked, can damage insulation or shorten the motor’s life. A thermal device uses a temperature-sensitive element (like a bimetal strip) to sense that rise in temperature and trip the circuit before damage occurs. Because the emphasis is on the heat-driven protection mechanism rather than a specific logic, contact, or control function, the generic term that fits naturally is a thermal device. While a relay, switch, or controller can be part of motor protection or control systems, the fundamental concept here is the temperature-based protective element, i.e., a thermal device.

Overload protection in motors is driven by heat. When a motor draws more current than it can safely handle, the windings heat up, which, if left unchecked, can damage insulation or shorten the motor’s life. A thermal device uses a temperature-sensitive element (like a bimetal strip) to sense that rise in temperature and trip the circuit before damage occurs. Because the emphasis is on the heat-driven protection mechanism rather than a specific logic, contact, or control function, the generic term that fits naturally is a thermal device. While a relay, switch, or controller can be part of motor protection or control systems, the fundamental concept here is the temperature-based protective element, i.e., a thermal device.