Understand the interface decision

Manual commands change who requests movement, not the physical capabilities of the yaw assembly. The controller should make active restrictions visible so an operator understands a refused command. Any special test mode with reduced protection needs its own controlled method and authorization.

Electric-yaw arrangements differ between turbine designs. These questions describe control and interface reviews, not confirmed MARSTON hardware or operating logic. The relevant machine design, mechanical limits and risk assessment must establish the permitted movement and response.

Put these inputs in the review record

Use a project-specific worksheet to capture the following information. For each entry, name the document, revision and person responsible for resolving any uncertainty.

• Functions that remain active in manual operating mode. Identify the exact configuration and the supporting document.
• The permitted local controls and operator visibility requirements. Keep the design assumptions visible in the project record.
• Travel, twist, brake and environmental restrictions. Name the responsible reviewer and resolve any missing information.
• Mode transfer, command release and return-to-automatic conditions. State how this entry will be verified during acceptance.

Define the acceptance boundary

Accept manual mode through a defined function list and tests of relevant restrictions. Do not assess it only by demonstrating movement in each direction. Confirm how the system stops movement and prevents conflicting commands from other control sources.

The operator instructions should describe the limits of manual authority in practical terms. Keep temporary service overrides separate so normal manual operation does not depend on an undocumented commissioning bypass.