What is a typical impedance threshold for warning systems in DC setups?

In DC systems, especially concerning warning systems, the typical impedance threshold is often set at around 500 ohms per volt. This value serves as a standard for ensuring that the system can effectively detect faults or conditions that could trigger an alarm.

The impedance threshold is crucial because it helps define the load that needs to be present on the system for it to effectively monitor and respond to issues. When the impedance is set too high, the system may become unresponsive, failing to alert users to potential problems. Conversely, if the impedance is set too low, it could lead to false alarms or erratic behavior of the warning system.

Thus, 500 ohms per volt strikes a balance conducive for reliable operation in detecting issues without generating unnecessary alarms.