A home electrical panel might not have a main breaker because it's a split-bus panel (common in 1950s-1970s homes), has a main disconnect located elsewhere, or uses a rule of six design 1 with multiple disconnect switches instead of a single main breaker. Looking at your electrical panel and can't find the main breaker? This common issue leaves many homeowners confused and worried about safety. The main disconnect is usually 200 amps but can sometimes be as low as 100 amps. The main disconnect is a safety device that lets you shut off all power to a house. A main breaker, or service disconnect, is a single switch designed to interrupt all electrical power flowing from the utility company into a home's electrical panel. Any subpanels are only required to have a disconnect breaker upstream in the main.