When should you expect the NO contacts to close in the ON-delay relay operation?

In an ON-delay relay operation, the NO (Normally Open) contacts are designed to close after a specific set time period has elapsed once the relay is energized. This characteristic is essential for applications where a delay before activation is needed, allowing for transient conditions to stabilize before the circuit is completed.

When power is applied to the relay, it does not instantly close the contacts. Instead, there is a built-in delay, which is defined during the design of the relay. The purpose of this delay can vary, including allowing other processes to prepare adequately for the operation that follows.

Thus, after the pre-determined delay period elapses, the NO contacts will close and allow current to flow through the associated load, completing the circuit. This function is crucial for applications where immediate activation could cause issues, making B the appropriate choice for when NO contacts close in an ON-delay relay operation.