ATPL - The services connected to a supply bus-bar are normally in:

Question id 545 - Aircraft General Knowledge - Airframe, Systems, Powerplant - ATPL - Airline Transport Pilot license

Parallel, So That Isolation Of Loads Decreases The Bus-bar Voltage.

Series, so that isolating one load increases the bus-bar current consumption.

Series, so that isolation of loads increases the bus-bar voltage.

Parallel, so that isolating individual loads decreases the bus-bar current consumption.