What is the first step to operate the main drainage eductor?

The correct first step to operate the main drainage eductor is to open the discharge valve. This action is crucial because the eductor relies on the flow of water through the system to create the vacuum necessary for its operation. By opening the discharge valve, you allow water to flow out, which initiates the suction process and enables the eductor to effectively remove water from the area being drained.

Opening the discharge valve ensures that the system is properly vented and prevents back pressure that could disrupt the operation. It's also essential to be aware of the flow direction and ensure that the system is ready to function efficiently. This foundational step sets the stage for subsequent actions, such as managing the suction valve and taking safety precautions for personnel.