True or False: The secondary of a current transformer may be opened while the transformer is energized.

The statement is false because opening the secondary of a current transformer while it is energized can create dangerous conditions, which may lead to high voltage spikes that can damage the transformer and pose safety risks. Current transformers are designed to provide a safe transformation of high currents to a lower, manageable level for measurement or protection circuits. When the secondary circuit is opened, the primary current can remain flowing, but without a closed secondary path, the transformer does not have a load to balance out the magnetic circuit. This situation can induce extremely high voltages across the open secondary terminals, which may lead to insulation failure and other hazards.

In general practice, it's crucial to ensure that the secondary of current transformers is always connected to a load, or short-circuited during maintenance, to prevent the dangers associated with exposure to high voltage. This principle underscores the importance of handling current transformers properly and adhering to safety protocols at all times to ensure safe operation.