Which devices are referred to for indicating when power is off?

Power Off Indicators are specifically designed to communicate the status of electrical systems, indicating when power is not present. These indicators are crucial for ensuring safety, allowing personnel to visually confirm that a circuit is de-energized before performing maintenance or inspections.

Power Off Indicators typically employ visual cues—such as lights or display screens—that provide clear, immediate information about the power status. This is essential in railway operations where safety is paramount, as it helps prevent accidents that could occur due to unexpected electrical energy.

While Signal Indicators, Warning Lights, and Automatic Sensors serve important functions within the railway system, they do not specifically indicate the status of power being off. Signal Indicators communicate messages related to train movements or system status, Warning Lights often indicate hazards or operational issues, and Automatic Sensors are usually designed for detecting various conditions rather than specifically showing whether power is available or not. Ultimately, the clarity and directness of Power Off Indicators make them the correct choice for this context.