Lifecycle Testing Machine

During my internship at ABB, I developed a machine that would more accurately test the robustness of residential circuit breakers. Currently, UL standards require all residential circuit breakers to be tripped and reset 10,000 times. For breakers that do not use an electronic tripping sensor, simply turning the breaker on and off using the switch does not actuate the mechanism used during an overcurrent trip. However, the correct latch movement can be simulated with a shock to the back side of the breaker. My task was to create a machine that could mechanically shock multiple breakers at once, reset them, and repeat until the programmed test was finished. I began with analyzing force requirements, then created a CAD model of the assembly.

Following the design of the mechanical portion, I worked on the electronic control box. It had two main functions: start and stop the motor, and display the current status of each breaker. Using my force analyses, I identified the motor and motor controller I would need. Then, using an Arduino, I created a circuit that would carry out the test plan inputted by the operator. Once the test began, the display would show the current cycle and identify which of the breakers were still operational. The Arduino would also keep a log of the specific cycle during which each breaker failed.

Finally, I worked with the machine shop to build a working prototype. I was able to get everything working by the end of my internship and it worked on the first try! I was able to present the design to the leaders of manufacturing for ABB North America and they were very impressed with the idea. Following a successful test run, this design would be used in the multiple factories throughout North America for quality assurance testing.