The SMTZ series refers to a type of universal circuit breaker, specifically a Type Z Miniature Circuit Breaker (MCB). These breakers are designed for highly sensitive applications and devices prone to short circuits, like those in electronics, according to RS Components. Type Z MCBs trip at much lower overloads than other types, typically between two and three times the rated current, according to EcoSoch.
Key Characteristics of Type Z MCBs:

Sensitivity: High sensitivity, tripping at low overloads.
Application: Used for protecting sensitive electronic circuits and devices.
Trip Time: Provide tripping protection within one-tenth of a second.
Function: Protects against overloads and short circuits.

Examples of Universal Circuit Breakers (including SMTZ series):

Miniature Circuit Breakers (MCBs): A common type of circuit breaker used in residential and commercial settings.

Ground Fault Circuit Interrupter (GFCI): Protects against electrical shocks by detecting ground faults.
Arc Fault Circuit Interrupter (AFCI): Protects against electrical fires caused by arc faults.
Residual Current Circuit Breakers (RCCB): Protect against electric shock by detecting and tripping on small current leakage.

In the context of SMTZ, it’s important to note that “SMTZ” likely refers to a specific manufacturer’s model or product line of Type Z MCBs, rather than a generic term for this type of breaker.