Clearing procedures in electrical installations: the electrical status space as model for training and planning

Maintenance personnel must take the clearing procedures, operating the necessary steps to assure that the system or portion of the system on which they plan to work is in an electrically safe working condition. The complexity of the electrical system normally determines the level of detail planning required for system clearing procedures. The clearing procedures should be completely written, checked and understood by all persons involved before applying them to any portion of the power distribution system. This paper reviews and enhances previous papers by investigating the basic concepts and definitions to give prominence to operating bonds and to help the procedure-project. It proposes some simple rules, a graphical representation and an algebraic model of electrical status to execute an auto-check of the clearing procedure. The model allows to memorize visually the logic procedures and to count the necessary locks. A software program, New Delhi 2000, based on these models has been developed for an aided or interactive training on network samples and for planning new networks.