What safety measure should be taken before working on electrical systems?

Prior to working on electrical systems, shutting off the power supply to the circuit is essential for ensuring safety. This step prevents electric shock during maintenance or installation tasks. When the power is off, there is a significantly reduced risk of accidental contact with live wires, which can have fatal consequences.

While other safety measures, such as wearing rubber gloves, can provide additional protection, they do not replace the necessity of de-energizing the circuit first. Turning off all lights in the building could lead to confusion or difficulty navigating the work area, and working only in daylight is not a practical or sufficient safety measure. Thus, de-energizing the circuit is the primary and most effective safety procedure to take before beginning any work on electrical systems.