One method of deenergizing a seal-in circuit is to use __________.

Using an input with normally closed (NC) contacts is an effective method for deenergizing a seal-in circuit. In a seal-in circuit, the relay remains energized even after the momentary contact is released, due to its self-holding mechanism. Incorporating NC contacts allows the circuit to be interrupted when the controlling device is activated.

When the activating device operates, it opens the NC contacts. This action breaks the circuit path leading to the relay coil, effectively deenergizing the relay and stopping the activation of the controlled equipment. This method is particularly reliable as it ensures that the circuit only remains powered under specific conditions, contributing to safety and operational control within the maintenance framework.

In contrast, other methods like the manual override, using another relay, or employing a solenoid may not provide the same level of control or reliability in interrupting the circuit automatically when required.