Abstract: This study presents issues on experimental testing os response speed, sensitivity and selectivity with use of the breadboard for smart relay protection of electrical networks that was developed in the University "Dubna". Testing was performed using a physical model of an electrical network comprising transmission lines, power transformers, electric motors, generalized load and substation buses. Method of emergencies simulation in the model, key points of the investigation tests to determine response speed, sensitivity and selectivity are described. Specific examples of determining these parameters for the electrical network model are shown.