Ultra high-speed circuit breaker with galvanic isolation

A circuit breaker apparatus housed in a case equipped with input terminals for connection to a power supply and output terminals for connection to a load, said circuit breaker apparatus comprising:

• a disconnecting switch including main contacts that connect the input terminals to the output terminals and a manually operable control mechanism for controlling the closing or opening of the main contacts.
• an electronic switch connected in electrical series with the disconnecting switch between the input terminals and the output terminals,
• a control circuit connected to the electronic switch for switching the electronic switch between an ON state, where current can flow from the input terminals to the output terminals, and an OFF state, where current cannot flow from the input terminals to the output terminals,
• a voltage sensor mechanism for determining when a voltage is present at the output terminals and for preventing the operation of the manually operable control mechanism of the disconnecting switch when a voltage is present at the output terminals, and
• prevention means for preventing the control circuit from switching the electronic switch to the ON state when the main contacts of the disconnecting switch are open and for enabling the control circuit to switch the electronic switch to the ON state when the main contacts are closed.