Operation Mosaic The first British atomic bomb was tested in Operation Hurricane at the Monte Bello Islands in Western Australia on 3 October 1952. Britain thereby became the third nuclear power after the United States and the Soviet Union, but just four weeks after Operation Hurricane, the United States successfully demonstrated a hydrogen bomb. The technology mastered in Operation Hurricane was six years old, and with the hydrogen bomb in hand, the US Congress saw no benefit in renewing cooperation with the UK. All the while Britain strove for independence, at the same time it sought interdependence in the form of a
Residual-current device to the appliance. The test button (8) allows the correct operation of the device to be verified by passing a small current through the orange test wire (9). This simulates a fault by creating an imbalance in the sense coil. If the RCD does not trip when this button is pressed, then the device must be replaced. Residual-current and overcurrent protection may be combined in one device for installation into the service panel; this device is known as a GFCI (ground fault circuit interrupter) breaker in the USA and Canada, and as an RCBO (residual-current circuit breaker with overload protection)