INTEGRATED ELECTRICAL SYSTEMS

A. General 685-1. Scope. This article covers integrated electrical systems, other than unit equipment, in which orderly shutdown is necessary to assure safe operation. An integrated electrical system as used in this article is a unitized segment of an industrial wiring system where all of the following conditions are met: (1) an orderly shutdown is required to minimize personnel hazard and equipment damage; (2) the conditions of maintenance and supervision assure that qualified persons will service the system; and (3) effective safeguards, acceptable to the authority having jurisdiction, are established and maintained. 685-2. Application of Other Articles. In other articles applying to particular cases of installation of conductors and equipment, there are orderly shutdown requirements that are in addition to those of this article or are modifications of them: Section More than One Building or Other Structure 225-8 Ground-Fault Protection of Equipment 230-95, Exception No. 1 Protection of Conductors 240-3(a) Electrical System Coordination 240-12 Ground-Fault Protection of Equipment 240-13, Exception No. 1 Grounding ac Systems of 50 to 1000 Volts 250-5(b), Exception No. 3 Orderly Shutdown 430-44 Disconnection 430-74, Exception Nos. 1 and 2 Disconnecting Means in Sight from Controller 430-102, Exception No. 2 Energy from More than One Source 430-113, Exception Nos. 1 and 2 Disconnecting Means 645-110, Exception Point of Connection 705-12, Exception No. 1 B. Orderly Shutdown 685-10. Location of Overcurrent Devices in or on Premises. Location of overcurrent devices that are critical to integrated electrical systems shall be permitted to be accessible, with mounting heights allowed to assure security from operation by nonqualified personnel. 70-714 NATIONAL ELECTRICAL CODE 685-12. Direct-Current System Grounding. Two-wire direct-current circuits shall be permitted to be ungrounded. 685-14. Ungrounded Control Circuits. Where operational continuity is required, control circuits of 150 volts or less from separately derived systems shall be permitted to be ungrounded.