Ordinance 807-81 - Laserfiche WebLink

• • Section 3: Section 700-12 of the National Electrical Code, 1981, as adopted in Section 1 of this Ordinance, reads as follows: C. Sources of Power 700-12. Emergency Systems. Current supply shall be such that in the event of failure of the normal supply to, or within, the building or group of buildings concerns, emergency lighting, emergency power, or both will be available within the time required for the application but not to exceed 10 seconds. The supply system for emergency purposes, in addition to the normal services to the building, shall be permitted to comprise one or more of the types of systems described in (a) through (3) below. Unit equipment in accordance with Section 700-12 (f) shall satisfy the applicable requirements of this article. In selecting an emergency source of power, consideration shall be given to the type of service to be rendered, whether of short-time duration, as for exit lights of a theater, or long duration, as for supplying emergency power and lighting due to a long period of current failure from trouble either inside or outside the building, as in the case of a hospital. Consideration shall be given to the location and/or design of all equipment to minimize the hazards that might cause complete failure due to floods, fires, icing, and vandalism. Assignment of degree of reliability of the recognized emergency supply system depends upon the careful evaluation of the variables at each particular installation. (a) Storage Battery. A storage battery of suitable rating and capacity to supply and maintain at not less than 87-1/2 percent of system voltage the total load of the circuits supplying emergency lighting and emergency power for a period of at least 1-1/2 hours. Batteries, whether of the acid or alkali type, shall be designed and constructed to meet the requirements of emergency service and shall be compatible with the charger for that particular installation. For a sealed battery, the container shall not be required to be transparent. However, for the lead acid battery which requires water additions, transparent or translucent jars shall be furnished. Automotive-type batteries shall not be used. An automatic battery charging means shall be provided. (b) Generator Set. (1) A generator set driven by a prime mover acceptable to the authority having jurisdiction and sized in accordance with section 700-5. Means shall be provided for automatically starting the prime mover on failure of the normal service and for automatic transfer and operation of all required electrical circuits. A time delay feature permitting a 15-minute setting shall be provided to avoid retransfer in case of short-time re-establishment of the normal source. (2) Where internal combustion engines are used as the prime mover, an on- site fuel supply shall be provided with an on-premise fuel supply sufficient for not less than 2 hours full-demand operation of the system. (3) Prime movers shall not be solely dependent upon a public utility gas system for their fuel supply or municipal water supply for their cooling systems. Means shall be provided for automatically tr4nsferring from one fuel supply to another where dual fuel supplies are used.