The CL-1510 visually demonstrates the protection system for electrical networks. Two (2) transmission lines are represented by luminous tracks in different colors. The lighted sections are those that normally carry current. Mechanically operated faults are simulated at different locations, following protective devices such as circuit breakers and section isolators so that it is easy to observe action/reaction, and the co-ordination of devices can easily be studied. Additional circuits and knife switches allow the network configuration to be changed and the faults to be isolated. The CL-1510 is also valuable in teaching students lineman code.