What should be checked before starting work on an electrical system?

Prior to commencing work on an electrical system, it is essential to ensure a thorough safety check to mitigate risks associated with electrical hazards. Each of the factors mentioned plays a critical role in maintaining a safe working environment.

The presence of a work order is vital as it outlines the specific tasks to be performed, thereby ensuring that all safety protocols are understood and followed. This documentation aids in tracking the work and confirming that it has been authorized.

Checking the power supply status is equally important. Before any work is done, confirming whether the power is on or off helps to prevent accidental electric shocks or other dangerous incidents. Knowing the status of the system allows for effective planning regarding safety precautions, such as using lockout/tagout procedures.

Monitoring voltage levels is also a key aspect. Understanding the voltage present in the system ensures that appropriate personal protective equipment (PPE) is worn, and helps in adhering to safety standards and regulations. This information protects the electrician from exposure to electrical shocks.

Together, these checks encompass a comprehensive safety protocol necessary before engaging with the electrical system, reinforcing why 'all of the above' is the correct answer. Each element contributes significantly to the overall safety and preparedness of the electrician, ensuring that no aspect of safety is overlooked.