Section 2 — Installation
Centurion
NOTE:
For more information about the installation of a standby system, you can order
2.1.1 NFPA STANDARDS
The following published standards booklets pertaining to standby electric systems are available form the National Fire Protection Association (NFPA), Batterymarch Park, Quincy, MA 02269:
•NFPA No. 37, STATIONARY COMBUSTION ENGINES AND GAS TURBINES.
•NFPA No. 76A, ESSENTIAL ELECTRICAL SYSTEMS FOR HEALTH CARE FACILITIES.
•NFPA No. 220, STANDARD TYPES OF BUILDING CONSTRUCTION
•NFPA No. 68, GUIDE FOR EXPLOSION VENTING
•NFPA No. 70, NATIONAL ELECTRICAL CODE.
•NFPA No. 30, FLAMMABLE AND COMBUSTIBLE LIQUIDS CODE.
•NFPA No. 10, INSTALLATION, MAINTENANCE AND USE OF PORTABLE FIRE EXTINGUISHERS.
2.1.2 OTHER PUBLISHED STANDARDS
In addition to NFPA standards, the following information pertaining to the installation and use of standby electric systems is available:
•Article X, NATIONAL BUILDING CODE, available from the American Insurance Association, 85 John Street, New York, N.Y. 10038.
•AGRICULTURAL WIRING HANDBOOK, obtainable from the Food and Energy Council, 909 University Avenue, Columbia, MO, 65201.
•ASAE
•A52.1, AMERICAN NATIONAL STANDARD FOR CHIMNEYS, FIREPLACES AND VENTING SYSTEMS, available from the American National Standard Institute, 1430 Broadway, New York, N.Y. 10018.
2.2GENERATOR LOCATION
Install the generator set, in its protective enclosure outdoors, where adequate cooling and ventilating air is always is available. Consider these factors:
•Install the unit where air inlet and outlet openings will not become obstructed by leaves, grass, snow, etc. If prevailing winds will cause blowing or drifting, consider a windbreak to protect the unit.
•Install the generator on high ground where water levels will not rise and endanger it.
•Allow sufficient room on all sides of the generator for maintenance and servicing. Allow three feet of space on all sides. NOTE: LOCAL LAWS OR CODES MAY REQUIRE DIFFERENT OFFSET DISTANCES.
•Where strong prevailing winds blow from one direction, face the generator air inlet openings into the prevailing winds.
•Install the generator as close as possible to the transfer switch. This reduces the length of wiring and conduit.
•Install the generator as close as possible to the fuel supply, to reduce the length of piping. HOWEVER, REMEMBER THAT LAWS OR CODES MAY REGULATE THE DISTANCE.
2.3GENERATOR MOUNTING AND
SUPPORT
Retain the generator compartment to a steel mesh or rebar reinforced concrete slab with
2.4BASIC STANDBY ELECTRIC
SYSTEM
Figure 2.1 shows a schematic diagram of a basic standby electric system. Both the UTILITY power supply and the STANDBY (GENERATOR) output are connected to an approved transfer switch. The transfer switch is required by electrical code and serves the following functions:
•Permits the LOAD circuits to be connected to only one power supply at a time.
•Prevents electrical backfeed between the generator and the UTILITY power circuits.
Notice that both the STANDBY and the UTILITY power supplies to the transfer switch are protected against overload by a main line circuit breaker.
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