A circuit protector is a circuit breaker that has a function to protect load equipment against overcurrent. Used for overcurrent protection of control panels and overcurrent of power supplies such as communication equipment, OA equipment, etc. Of the safety functions built into control panels and switchboards, the purpose is to protect electrical equipment from electrical circuits, and is used to protect low-capacity control circuits, motors, electronic circuits, etc. that are not protected by wiring breakers (MCCB). Switches with a switch function can actively cut off load current, and circuit protectors may be used as power switches for small-capacity devices. There are also trip-free structures and those with an alarm switch. When selecting a product, check whether it is AC / DC compatible or dedicated, rated current, number of poles, overcurrent operation characteristics, etc.