fig1 shows an industrial - rated circuit breaker 10 , such as described in aforementioned u . s . pat . no . 3 , 073 , 936 , with an operating handle 11 extending from the top with load straps 12 and line straps 13 arranged at opposite ends thereof . the movable contacts 15 at one end of the movable contact arm 14 and the fixed contacts 16 on the contact support 17 are shown in solid lines in the closed condition and in phantom lines in the open condition . the condition of the contacts are controlled by an operating mechanism ( not shown ) that is refrained from articulation by means of a trip latch 18 in the manner described within the aforementioned u . s . pat . no . 3 , 073 , 936 . in accordance with the invention , a trip unit conversion kit 9 , as shown in fig2 and 3 along with fig1 includes a programmer or electronic trip unit 21 such as described in aforementioned u . s . pat . no . 4 , 672 , 501 that connects with a trip actuator unit 20 by means of a wire conductor 22 and connectors 22a at one end . the trip unit conversion kit 9 is attached to the interior of the circuit breaker 10 by securing the conversion kit mounting bracket 29 to the circuit breaker accessory bracket 32 by means of screws 31 . the trip actuator unit 20 is similar to that described in u . s . patent application ser . no . 08 / 551 , 640 filed nov . 11 , 1995 entitled &# 34 ; electronic trip unit conversion kit for high ampere - rated circuit breakers &# 34 ;. upon receipt of a trip signal from the trip unit , the trip actuator unit 20 releases the flux shift plunger 19 which strikes a trip latch adjusting screw 23 . the adjusting screw 23 is threaded into a trip latch extension 24 which is secured to the circuit breaker trip latch 18 by means of a screw 25 . the flux shift plunger 19 rotates the trip latch 18 to the position shown in phantom allowing the operating mechanism ( not shown ) to separate the contacts 15 , 16 as further described in the aforementioned u . s . pat . no . 3 , 073 , 936 . the connector link 26 is attached to the reset arm 27 within the trip actuator unit 20 at one end and to the circuit breaker crossbar 30 at the other end to return the flux shift plunger 19 within the flux shift unit 43 from the actuated position depicted in solid lines to the reset position shown in phantom . the reset spring 28 which is anchored at one end through a hole 33 in the conversion kit mounting bracket 29 and at the other end to flux shift reset bracket 47 , biases the connector link 26 , and reset arm 27 immediately upon extension of the connector link to the position shown in phantom and returns the flux shift plunger 19 to its home position when the circuit breaker contacts 15 , 16 are returned to their closed position . this is brought about by interaction between the connector link 26 with the circuit breaker crossbar 30 at one end and by connection between the connector link 26 with the reset arm 27 at the opposite end , such that the rotation of the cross bar to close the circuit breaker contacts moves the connector link 26 and the reset arm 27 back to the position depicted in solid lines as described in the aforementioned u . s . patent application ser . no . 08 / 551 , 640 . as further described therein , the flux shift reset bracket 47 that controls the position of the flux shift plunger 19 , is attached to the reset arm 27 by means of bolts 41 and nuts 42 . as shown in fig2 and 3 , the mounting bracket 29 is shaped from a single metal plate and defines a front wall 44 extending in the horizontal plane as viewed in fig2 with a side wall 45 extending in the vertical plane at right angles to the front wall and with a bottom shelf 46 formed at one end . the electronic trip unit 21 is secured to the front wall of the conversion kit mounting bracket 29 with screws 34 and the trip actuator unit 20 is attached to the front wall via rubber grommets 35 , washers 38 , screws 36 and threaded apertures 37 . the rubber grommets are required to prevent the vibration within the circuit breaker interior from interfering with the operation of the flux shift unit 43 that controls the movement of the flux shift plunger 19 , described earlier . the bottom shelf 46 includes apertures 49 for connection of the mounting bracket with the circuit breaker accessory bracket 32 , as shown in fig1 . the connector link 26 is pivotally attached to the reset arm 27 by screw 39 and nut 40 . the position of the flux shifter reset bracket 47 is determined by the flux shifter reset spring 48 in the manner described in the aforementioned u . s . patent application ser . no . 08 / 551 , 640 . upon displacement of the connector link 26 by the circuit breaker crossbar 30 in fig1 the reset arm 27 and return spring 28 rotate flux shifter reset bracket 47 against the return bias of the flux shifter reset spring 48 to return the plunger 19 to the home position as shown in solid lines . an electronic trip unit conversion kit in the form of trip unit having automatic reset facility has herein been described . the conversion kit is mounted within the circuit breaker enclosure without requiring disassembly of any of the circuit breaker components .