Network monitoring relay, The NKR F1 monitors 1 to 3-phase networks for phase position, overvoltage and undervoltage. This makes it possible to react to neutral conductor interruptions and the overvoltages that usually occur., Subsequent damage to electrical systems can thus be prevented. The reaction time to network errors can be set from 0.1s to 5s. The relay switches on again either automatically after an error condition or only after acknowledgment by an external button., Dimensions: 18x55mm, 230V AC - 1W pf 10A, Uvar 170-230V