universal chassis (same approach as Masterpact); o through door drawing in and out, o through door closing and opening of the breaker, o meets all the requirements for incoming breakers; • basic chassis: o drawing in and out with door open, o through door closing and opening of the breaker.Compact moulded case circuit breakers come in single-pole, two-pole, three-pole and four-pole versions. Available in fixed or drawout patterns, they are designed for the control and protection of electric circuits. Compact circuit breakers are equipped with trip units providing : • protection against overloads by adjustable thermal releases or solid state trip units (control units), • protection against short circuits by adjustable magnetic releases or solid state trip units (control units)