What term is used for switching in substations to ensure capacity for customer load and provide alternate sources?

Bank switching is the correct term for switching in substations that is used to ensure capacity for customer load and to provide alternate sources of power. This process involves transferring load from one transformer bank to another or between different sections of a distribution network. The primary purpose of bank switching is to balance the electrical load across multiple transformers, which helps to prevent overload on a single unit and ensures that power can be redirected if one source is unable to provide the necessary capacity due to maintenance or failure.

By effectively managing the load distribution, bank switching plays a crucial role in maintaining a stable and reliable power supply to customers. It is integral to the operation of electrical substations and contributes to grid efficiency, reliability, and stability.

The other choices refer to different concepts. Isolation pertains to ensuring that certain parts of a system are de-energized for safety purposes, manual switching refers to physically changing connections by operators rather than through automated systems, and load switching generally involves the management of electrical loads but does not specifically refer to the practice of switching between transformer banks for capacity management.