Symbol U in electrical schematics represents which of the following?

The symbol U in electrical schematics denotes a circuit breaker that has both thermal and magnetic overloads (OLs). This type of circuit breaker is designed to provide precise protection against both overheating and short-circuit conditions. The thermal component of the breaker protects against overloads caused by excessive current flow that can lead to overheating, while the magnetic component is designed to react quickly to short-circuits, interrupting the current flow almost instantaneously to prevent damage to the circuit and connected equipment.

This dual protection mechanism makes the circuit breaker versatile and effective in various applications, ensuring enhanced safety within electrical systems. By recognizing symbol U as representing a circuit breaker with both thermal and magnetic overload capabilities, professionals can make informed decisions regarding circuit protection and system reliability in their electrical designs and installations.