What must occur for the ON-delay relay to activate the timed contacts?

For an ON-delay relay to activate the timed contacts, time must indeed be allowed to pass after the relay is energized. When power is applied to the coil of the ON-delay relay, the relay begins its timing cycle. The relay's contacts remain in their default state until the preset time interval elapses. Once that time duration is completed, the contacts change state, allowing the circuit to be completed or changed as intended.

This mechanism is essential in various applications where a delay in activating a circuit is needed. The operation of the relay depends on this timed interval, which distinguishes an ON-delay relay from an OFF-delay relay or other types of relays.

Other scenarios like cutting off the power or interrupting the circuit would not lead to the relay completing its timing cycles. Rather, these events would deactivate or hold the relay in its initial state. Manned manual control of contacts does not fit the automatic operation that ON-delay relays are designed for, which automates the timing function without manual intervention.