A turbine is to be disabled for installation and service by means of.

• A. Mechanical brakes
• B. Short circuiting
• C. Open circuiting
• D. Any of these

Answer: (D)

When preparing a turbine for installation or service, the goal is to prevent any motion or energy from being delivered or generated. There are multiple valid ways to achieve this. A mechanical brake can be applied to hold the rotor still, physically preventing rotation. Short-circuiting the generator’s output creates electromagnetic braking, which also stops or prevents rotation and generation while work is done. Opening the circuit, i.e., isolating the generator from its power source and the grid, removes all energized paths so no energy can flow to or from the machine. Any of these approaches can achieve a safe, zero-energy state for maintenance, so they’re considered acceptable methods depending on the system design and safety procedures.