This MicroLogic 4.2 AL is a 3P 3d electronic trip unit used on ComPacT NSX 100/160/250 circuit breakers. This 40A rated electronic trip unit is an optimal choice for all standard and special applications. It features customizable long term protection against overloads. It also offers customizable short term protection and fixed instantaneous short circuit protection. MicroLogic 4.2 AL offers a residual current alarm without tripping, available on the terminal block. MicroLogic 4.2 AL indicates overloads with alarm LEDs. The green Ready LED flashes when the circuit breaker is ready to trip. This product is part of our EcoStruxure Power architecture when combined with the PowerTag NSX and ComPacT NSX basic switch.