Final answer:
Impulse voltage testing is important for verifying that power system components can withstand transient overvoltages. It is done to ensure safety and prevent failures. Linemen have unique methods for ensuring safety before maintenance, and various devices are used to protect against electrical hazards.
Step-by-step explanation:
Testing power system components, such as line insulators, with impulse voltage is a requirement because these components are exposed to transient overvoltages caused by lightning strikes or switching surges in the system. Impulse voltage testing simulates these high voltage spikes that occur in very short durations to ensure that the insulation and other power system apparatus can withstand these extreme conditions without failure. The testing provides confidence in the durability and safety of the electrical infrastructure.
Linemen may touch a power line with the back of their hand as a final check to ensure the line is de-energized before maintenance because the involuntary muscle reaction to shock would cause the hand to pull away, potentially reducing the risk of gripping the conductor which could lead to electrocution. Shock hazards are also mitigated through the use of devices like circuit breakers and fuses which interrupt excessive currents, and ground fault interrupters (GFIs) which prevent shock by detecting loss of current to unintentional paths. This ensures both the protection of electrical systems and the safety of individuals working with or around them.