Overcurrent Protection Testing

This 'back-to-the-basics' video that explains how non-directional overcurrent works. It shows the difference between a fuse and an overcurrent protections scheme with current transformer, relay and circuit breaker. The overcurrent – time diagram is introduced and explained why different trip times make sense to obtain selectivity of a system with more than one relays. As a last step the reason for protection testing is given and shown how it can be done.