2a352h Volume 3 Chapter 1

The PMA (Power Management Annunciator) is a system that allows for the control and monitoring of various power states in an aircraft. Among these power states, the mode that can be controlled using the PMA is the maintenance mode. This mode is typically used during maintenance operations when the aircraft is on the ground. It allows for the activation of specific systems and functions needed for maintenance tasks, while other non-essential systems can be deactivated. This helps in conserving power and ensuring safety during maintenance operations.

The primary operating power on the F-22 aircraft is 270 vdc. This means that the aircraft operates on a direct current (dc) power supply with a voltage of 270 volts.

The correct answer is "Any voltage above 22 vdc". This means that in order to energize the coil of the voltage relay inside an RCR, the voltage applied should be higher than 22 volts direct current. Voltages below 22 vdc or any voltage in alternate current (vac) would not be sufficient to energize the coil.

The external power applied to the F-22 aircraft consists of 270 vdc and 28 vdc. This means that the aircraft requires a direct current (dc) power supply of 270 volts and 28 volts.

There are a total of 21 caution and advisory messages used to display the electrical power system status. Out of these, 8 messages are countdown messages and 13 messages are advisory messages.

If the CSD temperature rises to an overheat condition, the correct action to prevent further damage would be to disconnect the CSD. Disconnecting the CSD (Constant Speed Drive) would interrupt the power supply to the system, stopping any further heat generation and preventing potential damage to the components. This would allow the system to cool down and prevent any further overheating.

The F-22 aircraft uses a sealed maintenance free 28 vdc NiCad battery. This type of battery does not require regular maintenance and is sealed to prevent leakage. It operates at a voltage of 28 vdc. NiCad stands for nickel-cadmium, which is the type of battery chemistry used in this battery.

The electrical power mode determines which loads may be powered if power is limited. Different power modes prioritize certain loads over others based on their importance or criticality. For example, in a power-saving mode, non-essential loads may be temporarily turned off to conserve power. Therefore, the electrical power mode plays a crucial role in determining which loads can be powered when power is limited.

The three generators that make up a brushless ac generator are the PMG (Permanent Magnet Generator), the exciter, and the main armature windings. The PMG generates a stable and constant voltage to power the exciter, which in turn produces the magnetic field required for the main armature windings to generate the desired output voltage. This configuration eliminates the need for brushes and slip rings, making the generator more reliable and requiring less maintenance.

The three internal components that make up TR are a cooling fan, a step-down transformer, and a diode bank. These components are essential for the proper functioning of TR. The cooling fan helps to regulate the temperature and prevent overheating. The step-down transformer is responsible for reducing the voltage to a suitable level. The diode bank is used to convert the alternating current (AC) to direct current (DC) for further use.

The F-22 emergency power generation subsystem consists of the auxiliary generator, the auxiliary GCU, and dc contactor K704. These components work together to provide emergency power in case of a power failure or other electrical issues. The auxiliary generator generates the power, the auxiliary GCU controls and regulates the power, and dc contactor K704 helps to distribute the power to the necessary systems.

The available power to the F-22 when the stored energy system is the only source of power to the auxiliary generator is 5 kW.

Inverter 2 transmits control signals to PDC 6.

The auxiliary GCU (Generator Control Unit) provides functions to prevent ground power that is not in compliance with electrical power standards from being applied to the aircraft. It acts as a backup system to ensure that only the appropriate and safe electrical power is supplied to the F-22 aircraft.

The three types of GCU protection circuits used only during parallel operation are RBC (Reverse Blocking Contactor), neutral current, and unbalanced current. These protection circuits are specifically designed to monitor and control the flow of current in parallel operation, ensuring that the system remains balanced and protected against faults. The RBC circuit is responsible for preventing reverse current flow, while the neutral current circuit monitors the current flowing through the neutral conductor. The unbalanced current circuit detects any imbalances in the current distribution among the parallel circuits.

There are three inverter regulators that are part of the flight control system power.