What technique is used to prevent two contactors from becoming energized at the same time?

Interlocking is a critical technique in electrical systems designed to prevent the simultaneous energization of two contactors, which can lead to equipment damage, safety hazards, or system malfunctions. This method employs a configuration of circuits, where one contactor's activation is dependent on the status or position of another contactor.

When interlocking is implemented, the control logic ensures that if one contactor is energized, the other cannot close or become energized until the first one is deactivated. This provides a reliable safety mechanism, especially in systems where the operation of different components is interdependent and must not occur simultaneously.

For example, in motor control applications, interlocking ensures that two motors that cannot operate at the same time, such as those driving opposing loads, do not inadvertently run together, which could cause a mechanical failure or unsafe operating conditions.

Other techniques like sequential switching or load balancing address different aspects of electrical control systems and do not directly ensure mutual exclusivity in energization. Therefore, interlocking stands out as the most effective technique for this specific purpose.