In aircraft electrical systems, what is the function of a bus bar?

• A. It stores electrical energy for the aircraft bus.
• B. It distributes electrical power to multiple circuits from a single source.
• C. It converts AC to DC.
• D. It serves as a protective device for overload.

Answer: (B)

In aircraft electrical systems, the function of a bus bar is to distribute electrical power from a single source to multiple circuits. It is a low-impedance conductor that provides a common connection point, allowing many feeders to be fed from one source with minimal voltage drop and resistance. This is different from storage devices, which hold energy (batteries or capacitors), from devices that convert AC to DC (rectifiers/converters), or from protective devices that interrupt current during overloads (fuses or circuit breakers). The bus bar’s role is to enable efficient, reliable sharing of power across many circuits from a central source.