What is the function of the galley master button on the ERJ 175?

The function of the galley master button on the ERJ 175 is to cut power to both the forward and aft galleys. This button is essential for safety and efficiency during various phases of airline operations, especially during maintenance or when the aircraft is on the ground. By deactivating power to the galleys, it ensures that any equipment or appliances within the galleys do not inadvertently operate, which could pose a risk or lead to equipment malfunction.

The other options address functions that are not associated with the galley master button. For example, the galley work lights are controlled separately and are not inherently tied to the power supply of the galleys themselves. The activation of the water system is also a distinct function that does not rely on the galley master button. Lastly, locking the galley access doors is a safety feature that operates independently from the power controls of the galley systems. Hence, the galley master button is specifically designed to manage electrical power to the galley areas, ensuring a streamlined and safe operation within the aircraft.