This thesis presents background on power system protection, relay principles, modern relay technology and relay testing, to support the design, practical set up and proposals for use of a new relay lab at NTNU.The paper includes a theoretical part describing the components of power system protection, their function and attributes. To better the understanding of the importance of power system protection, a short study of the different types of faults that may occur in a power system and how they can be calculated has been made.One chapter covering the principles of protective relaying functions relevant for the lab, is included. It covers the theory of overcurrent (including directional), distance and differential protection, as well as challenges one may encounter when applying these protective functions.A chapter on modern relay technology, describing the possibilities and benefits of micro-processor based relays, especially with regards to communication, is a part of the report. This chapter also includes sections describing the inputs and outputs, logic and function of modern relays.The essentials of relay testing is described in the paper. The different methods available for the testing of relays; scaled physical networks, relay testers and fault simulators are mentioned. Focus has been put on use of relay testers as it is most relevant for the lab. A description of common test procedures is also included. Selected relevant software has been studied to find a software which can be used in the lab exercises.Discussion of practicalities regarding the lab, i.e. the design and set up of the lab is also made in the thesis. Opportunities for, and use of the lab have been discussed. The basics of relay configuration is explained. Proposals for lab exercises that can be performed in the new relay lab are presented near the end.A list covering proposals for further work for the relay lab is the final part of the thesis.