Miniature Circuit Breaker’s job: On-off control + Fault protection
✅ Normal: Conductive parts pass power
⚠ Fault: Protection triggers, breaks circuit in 0.01-1s!
⚡ Key Scenarios
Handle "ON" → Latch locks contacts, spring stores energy
Current: Terminal → Fixed contact → Moving contact → Terminal
Overload bends bimetallic strip
Latch releases → Contacts separate
Arc extinguished by grid → Reset handle post-fix
Protection
Short-circuit = Coil activates armature
Contacts separate (＜0.1s!) → Arc device puts out arcs
(High-End)
Leakage → Transformer detects current difference
Triggers tripping → Test button verifies function
Open: Handle "OFF" → Contacts separate
Close: Handle "ON" → Contacts lock
Core Component Tips
Bimetallic Strip: Timely overload trip
Arc Grid: 0.5-1mm spacing = fast arc extinction
Silver Contacts: ≥85% Ag = low resistance + anti-welding
Leakage Transformer: Detects ≥30mA → Trip in 0.1s
