North American Electric Reliability Corporation (NERC) Practice Exam

When a capacitor bank is removed from service, the immediate effect on voltage is a decrease. Capacitor banks are used to provide reactive power support and help to raise the voltage levels in the power system. They improve voltage stability and either correct phase angle differences or supply reactive power needed to keep the system operating efficiently.

When a capacitor bank is taken offline, the reactive power supply from that bank is removed, which can lead to an increase in reactive power demand on the remaining components of the system. This situation often results in a drop in the overall voltage level because the system loses the support that the capacitor bank was providing.

In summary, removing a capacitor bank leads to a decrease in voltage due to the loss of reactive power support necessary for maintaining voltage levels within the electrical grid.