Abstract: A switching apparatus contained inside box B consists of standard electrical units, and arranged in a way which is particularly advantageous for the purpose at hand. One of these units is a circuit breaker box containing two interruptible circuits, and having a mechanical reset switch. There are also a pair of magnetic contactors. Each magnetic contactor is used for switching a single conductor, and includes a pair of contact plates which are normally open so that current cannot pass through them, together with a coil which can be energized for causing the plates to close. In addition to the circuit breaker box and the magnetic contactors, there are heavy copper conductors, or buss bars, which make the necessary connections between the circuit units.