Which electrical device is specifically designed to melt and break a circuit if the current exceeds a set limit?

The device that is specifically designed to melt and break a circuit if the current exceeds a set limit is a fuse. A fuse serves as a safety mechanism in electrical circuits; it contains a metal conductor that melts when it reaches a specific temperature due to excessive current flow. This interruption in the circuit effectively prevents potential hazards, such as overheating and electrical fires.

Fuses are rated for specific current limits, and once the current exceeds this limit, the fuse will blow, cutting off the electrical flow and protecting the rest of the system. This characteristic makes it an essential component in various applications to ensure safe operation.

The other devices mentioned serve different functions. For instance, a Ground Fault Circuit Interrupter is designed to prevent electric shock by quickly shutting off power when it detects an imbalance between incoming and outgoing current. A Service Entrance Panel is responsible for distributing electricity from the utility supply to various circuits throughout a building, while a transformer alters the voltage levels in a circuit but does not have the protective function of breaking the circuit due to excessive current.