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

IEEE / ANSI

ANSI/IEEE thermal-magnetic circuit breaker symbol

The thermal-magnetic form combines two protection responses associated with the same breaker. An expanded drawing may show the operating path and additional functional marks, but device selection and coordination still depend on the scheduled breaker and trip data.

Drawing use

SLD / Schematic

Application

Power distribution

Reference family

IEEE / ANSI / Manufacturer

Form evidence

Autodesk IEEE-oriented 1 Pole Circuit Breakers functional form. Autodesk explicitly publishes this block under IEEE Symbol Preview. The counterpart is the matching functional concept; no equivalence of every detailed standard graphic is asserted.

A distinction that matters

The combination is different from an electronic relay issuing a trip to an otherwise separately protected breaker.

Full referenceAdd to legend

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

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