In a start relay, are the contacts normally open or closed when the system is off?

In the context of a start relay, the contacts are normally closed when the system is off. This configuration is crucial for the operation of the relay, as it allows the circuit to remain closed until an external voltage or signal energizes the relay.

When the relay is not powered, the contacts remain closed, facilitating the flow of electrical current for other components in the circuit that may need to be active. Once the relay receives a signal to start (typically from a control circuit), it opens the contacts, which then allows the system (like a compressor in a refrigeration unit) to initiate its operation. This design ensures that, during the off state, power can still circulate through necessary components, preventing disruption of the electrical system when the relay is not engaged.

Understanding this configuration is essential for troubleshooting or designing circuits involving start relays, as it directly impacts the operational flow within the system.