What safety measure should be taken when working on live electrical equipment?

Turning off the power supply first is the most critical safety measure when working on live electrical equipment. This action significantly reduces the risk of electric shock, injury, or even fatality. By ensuring that the equipment is de-energized, you eliminate the potential for accidental contact with live wires or components, allowing you to work safely and effectively.

In addition, working on live equipment can lead to unpredictable and dangerous situations where even a momentary lapse in attention could result in serious harm. De-energizing the equipment not only protects the person performing the work but also mitigates risks to others in the vicinity.

While using insulated tools and ensuring tools are dry can enhance safety, these measures do not replace the fundamental importance of de-energizing the equipment before beginning work. Therefore, turning off the power supply is the best and most comprehensive safety practice in this scenario.