A live duplex wire can be de-energized quickly and safely by cutting ________.

The most effective and safe way to de-energize a live duplex wire is by cutting one wire at a time using a diagonal cutter. Diagonal cutters are specifically designed to cut through wire cleanly and create a safe separation of conductors. By addressing one wire at a time, the risk of short-circuiting or causing an arc is minimized, which is critical when working with live electrical circuits.

This method allows the technician to maintain better control and focus on cutting each conductor individually, reducing the chance of mishap. Handling wires one at a time also enables the worker to observe and assess the situation more thoroughly, further ensuring safety.

Using a knife might not provide the precision needed when working with insulated wires, and it may risk damaging the insulation or causing unexpected electrical hazards. Mechanical pliers can also deliver less control and precision in a cutting operation when compared to diagonal cutters, making them less ideal for this application. Moreover, cutting across any wire with standard electrical pliers or other tools could lead to a hazardous situation, as it bundles the risk of cutting multiple wires simultaneously and potentially causing electrical faults.

In summary, cutting one wire at a time using a diagonal cutter is the recommended method, ensuring safety and precise operation when handling live duplex wires.