Once the device has switched due to a transient, it will stay in this low impedance state until the voltage across it falls below a specific value, known as the holdover voltage. When selecting one of these devices, it is important to make sure the voltage of the protected system is less than the holdover voltage value of the protector.
Refers to a device which prevents hazards due to thermal run-away. The device is a thermal sensitive switch which operates at a predetermined temperature, shorting the terminals of the protection device providing a low resistance path. Protects against the consequences of power cross conditions.