Square D PowerPacT family is industry leading innovation and protection for heavy duty commercial and industrial appliacations Each MicroLogic trip unit is equipped with an interchangeable long-time rating plug to provide maximum design flexibility, system protection, and field upgradeability. Trip unit requires an adjustable rating plug to determine the long-time pickup range of the circuit breaker. These plugs can be ordered separately for field-installable upgrades. This trip unit model is standard 3.0 (UL/ANSI only) with LI protection without additional features.