What tool is used to ensure a cable is electrically isolated prior to cutting?

The megohmmeter, also known as a megger, is the appropriate tool used to ensure a cable is electrically isolated prior to cutting. This device measures insulation resistance, providing a high-voltage output to test the integrity of the insulation surrounding the conductors. By doing so, it helps to determine if the cable is free of any shorts or poor insulation that could result in electrical hazards when the cable is cut.

Using a megohmmeter is crucial in preventing potential electrical shocks or short circuits that might occur if a cable is inadvertently still energized. It effectively isolates the circuit and checks for safe working conditions.

Other tools like the volt-ohm meter, clamp meter, and multimeter serve different purposes. A volt-ohm meter is primarily used to measure voltage, resistance, and sometimes current, but it doesn't test insulation resistance under high voltage. A clamp meter measures current flow in a conductor without directly connecting to the circuit, which doesn't provide information about insulation. A multimeter is versatile for various measurements but lacks the capability to conduct high-voltage insulation tests. Thus, the megohmmeter is specifically designed for the task of ensuring electrical isolation through insulation resistance testing.