What testing method can indicate potential hazardous voltages in electrical equipment?

Live testing is the method used to indicate potential hazardous voltages in electrical equipment because it involves measuring electrical parameters while the equipment is energized. This approach allows technicians to directly assess the operating conditions, identify any unsafe voltage levels, and ensure the system is functioning as it should under actual load conditions. Live testing is critical for detecting issues such as insulation breakdown or improper grounding that may not be evident during non-energized checks.

In contrast, visual inspection focuses on the physical condition of equipment without imparting any electrical analysis. Analog testing generally refers to using tools that provide continuous readings rather than discrete digital information, which may not specifically highlight hazardous conditions. Passive testing typically examines the system without applying any power, therefore missing the opportunity to detect live voltage issues that could be hazardous in a live scenario. Hence, live testing is essential for ensuring safety when working with electrical systems.