Understand the difference.

Compare the meaning, drawing context and source references of two entries. A similar graphic or shared abbreviation does not establish equivalence.

CB TM

Symbols

Thermal-magnetic circuit breaker

A thermal-magnetic breaker combines overload response with a magnetic response to high current. Its functional annotation helps distinguish the trip mechanism from an electronic trip unit.

Drawing use

SLD / Schematic

Application

Power distribution

Reference family

IEC / Manufacturer

A distinction that matters

An electronic trip unit may provide similar protection functions through a different measurement and operating system.

Full referenceAdd to legend

CB

Symbols

Circuit breaker

A circuit-breaker representation identifies a device capable of interrupting its circuit under the operating conditions for which it is rated. The drawing should connect that device to its equipment identification, protection arrangement and control information. The graphical mark alone does not establish the current rating, breaking capacity or trip settings.

Drawing use

SLD / Schematic

Application

Power distribution

Reference family

IEC / IEEE / ANSI

A distinction that matters

A disconnector provides isolation; it is not automatically a fault-interrupting circuit breaker. Check published device capabilities.

Full referenceAdd to legend

Original educational previews. Follow the source references on each full entry for the appropriate standard or selected product.