Optional accessories for the NZM circuit breaker series offer an extensive portfolio of application options for worldwide use. Installation is flexible and easy thanks to modular function groups. Notes: Immediate shutdown of the NZM circuit breaker or N load-break switch when the control voltage drops below 35-70% US. Can be used for EMERGENCY STOP devices in conjunction with EMERGENCY STOP buttons. If the undervoltage release is de-energized, touching the main switch contacts is safely prevented when attempting to switch it on. The undervoltage release cannot be installed at the same time as the leading auxiliary switch NZM..-XHIV.. or the shunt release NZM..-XA.. Can be used for: NZM2(-4), N(S)2(-4), NZM3(-4), N(S)3(-4)