This article provides an in-depth exploration of how circuit breakers function in substations, covering their types, components, operation, and significance, supplemented with examples for clarity. ZW32-12 Outdoor high voltage vacuum circuit breaker,also known as outdoor vacuum column circuit breaker,which is mainly used for closing and opening the load current,overloads current and short circuit current in power system. Circuit breakers perform two fundamental roles in substations: (1) interrupt high fault. A circuit breaker in substation systems interrupts fault current to protect transformers, busbars, and grid assets while supporting protection coordination, maintenance planning, and long-term substation reliability. Circuit breakers are essential components in They are designed to automatically interrupt the flow of electricity during In substations, where the management of This article provides an in-depth. Design, manufacturing, assembling, transportation of 138 (69)kV 40MVA mobile substation. CHINT delivered a 138 (69)kV 40MVA mobile substation to Honduras, featuring dual-voltage adaptability (138kV/69kV to 34. 5kV) for emergencies, grid upgrades, and remote power needs.