Final answer:
Pressing the MAN ON switch on an aircraft's Emergency Electrical Power Panel will not usually cause the RAT to deploy while on the ground, as the RAT is mainly designed for automatic deployment in flight.
Step-by-step explanation:
The question is inquiring about the operation of an aircraft's Emergency Electrical Power Panel, specifically the action of pressing the MAN ON switch in relation to the deployment of the RAT (Ram Air Turbine). If the MAN ON switch is pressed on the ground, it generally will not deploy the RAT because the RAT is designed to deploy automatically in flight when it detects a significant loss of power in the main electrical systems. In most aircraft, the RAT will only deploy manually when specific conditions are met to ensure the safety and structural integrity of the aircraft, and this typically does not include manual deployment while the aircraft is on the ground.
However, there could be maintenance or test procedures that may allow for manual deployment of the RAT on the ground, but those are usually controlled environments and require a specific protocol to be followed. It is not standard practice for a pilot or a crew member to deploy the RAT manually on the ground outside of these controlled scenarios.