I salvaged this breaker unit from the scrape yard. Compared to every other breakers i have seen before, this is very different. It has 5 terminals.
The labels are very clear but there is no information about the usage of its terminals. The terminals are labelled A, B and C. Its not even labelled clearly which side is load and which side is line.
The greatest mystery is the terminal C. What is it's purpose and how is it used?