Network Protector

A network protector is an electric protective device used in electricity distribution systems that automatically disconnects its associated distribution transformer from a secondary network whenever power begins to flow in the reverse direction. It is used on both spot networks and grid networks, and because a secondary grid draws on multiple sources to supply the same load, a fault on any one source is automatically isolated by its network protector without interrupting service from the others, improving continuity of supply. Network protectors are especially common in densely populated urban areas, where secondary grids are often used to serve the many customers packed into a small downtown area.