A circuit breaker comprising: a housing including a front cover selectively coupled to the housing, the front cover including an opening defined therethrough; and a trip unit selectively coupled to the housing, the trip unit comprising a trip unit housing, characterized in that the trip unit housing includes a first receptacle and a second receptacle formed thereon or therein and a front face accessible via the opening of the front cover when the front cover is coupled to the housing, the front face having a number of adjustment mechanisms for adjusting one or more characteristics of the trip unit; and the trip unit comprises an access door having a first cylindrical member extending along a hinge axis in a first direction, a second cylindrical member extending along the hinge axis in a second direction opposite the first direction, and a thickened portion having a contoured outer surface disposed adjacent the first cylindrical member and the second cylindrical member, wherein, when the front cover is uncoupled from the housing, the access door is moveable from: (i) a first state wherein the first cylindrical member is disposed in the first receptacle and the second cylindrical member is disposed in the second receptacle such that the access door is coupled to the housing and generally free to rotate about the hinge axis through at least a first predetermined degree range (α), and (ii) a second state in which the access door is decoupled from the trip unit housing responsive to the access door being rotated beyond the first predetermined degree range (α) and the contoured outer surface interacting with a portion of the trip unit housing, and wherein, when the access door is disposed in the first state and the front cover is coupled to the housing, the front cover restricts rotation of the access door about the hinge axis to a second predetermined degree range (α') less than the first predetermined degree range (α). a housing including a front cover selectively coupled to the housing, the front cover including an opening defined therethrough; and a trip unit selectively coupled to the housing, the trip unit comprising a trip unit housing, characterized in that the trip unit housing includes a first receptacle and a second receptacle formed thereon or therein and a front face accessible via the opening of the front cover when the front cover is coupled to the housing, the front face having a number of adjustment mechanisms for adjusting one or more characteristics of the trip unit; and the trip unit comprises an access door having a first cylindrical member extending along a hinge axis in a first direction, a second cylindrical member extending along the hinge axis in a second direction opposite the first direction, and a thickened portion having a contoured outer surface disposed adjacent the first cylindrical member and the second cylindrical member, wherein, when the front cover is uncoupled from the housing, the access door is moveable from: (i) a first state wherein the first cylindrical member is disposed in the first receptacle and the second cylindrical member is disposed in the second receptacle such that the access door is coupled to the housing and generally free to rotate about the hinge axis through at least a first predetermined degree range (α), and (ii) a second state in which the access door is decoupled from the trip unit housing responsive to the access door being rotated beyond the first predetermined degree range (α) and the contoured outer surface interacting with a portion of the trip unit housing, and (i) a first state wherein the first cylindrical member is disposed in the first receptacle and the second cylindrical member is disposed in the second receptacle such that the access door is coupled to the housing and generally free to rotate about the hinge axis through at least a first predetermined degree range (α), and (ii) a second state in which the access door is decoupled from the trip unit housing responsive to the access door being rotated beyond the first predetermined degree range (α) and the contoured outer surface interacting with a portion of the trip unit housing, and wherein, when the access door is disposed in the first state and the front cover is coupled to the housing, the front cover restricts rotation of the access door about the hinge axis to a second predetermined degree range (α') less than the first predetermined degree range (α).