The lower part for retractable Tmax XT4 compact circuit breakers with rated currents up to 250 A is available in 3- or 4-pole versions. The Tmax XT4 can be equipped with thermal-magnetic trip units for the protection of DC and AC networks, as well as with electronic trip units for the protection of AC networks. The series is also suitable for use in communication systems and 400 Hz installations. The Tmax XT4 compact circuit breakers are available in a derived version as load disconnect switches. The series of electronic overcurrent trip units Ekip complements the offering. Ekip is an interchangeable, microprocessor-controlled trip unit designed for extreme reliability and precision, signaling operational and protection functions via LEDs. A communication module Ekip Com can be integrated into the Tmax XT4 without taking up space. Additional accessories are available.