Generac Power Systems 005564-0, Owner'S Manual

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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 EP-364.2, INSTALLATION AND MAINTENANCE OF FARM
STANDBY ELECTRIC POWER, available from the American
Society of Agricultural Engineers, 2950 Niles Road, St. Joseph,
MI 49085.
• A52.1, AMERICAN NATIONAL STANDARD FOR CHIMNEYS,
FIREPLACES AND VENTING SYSTEMS, available from the
American National Standard Institute, 1430 Broadway, N ew
York, N.Y. 10018.
2.2 BASIC STANDBY ELECTRIC
SYSTEM
Figure 2.1 shows a schematic diagram of a basic standby electric
system. Both the UTILITY power supply and the STANDBY (GEN-
ERATOR) output are connected to an approved transfer switch.
The transfer switch is required by electrical code and serves the
following functions:
• Allows 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.
NOTE:
The manufacturer recommends the use of a “GTS” type transfer
switch in conjunction with this generator.
Figure 2.1 – Basic Standby Electric System
2.3 EMERGENCY CIRCUIT
ISOLATION METHOD
This prevents overloading the generator by keeping electrical
loads below the wattage/amperage capacity of the generator. If
the generator is powering only critical loads, within the wattage/
amperage capacity, during utility power outages, consider using
the emergency circuit isolation method.
Critical electrical loads are grouped together and wired into a sepa-
rate “Emergency Distribution Panel.” Load circuits powered by that
panel are within the wattage/amperage capacity of the generator
set. When this method is used, it is difficult to overload the gen-
erator. The transfer switch must meet the following requirements:
• It must have an ampere rating equal to the total amperage rating
of the emergency distribution panel circuit.
• Have it installed between the building’s main distribution panel
and the emergency distribution panel.
2.4 TOTAL CIRCUIT ISOLATION
METHOD
When a generator capable of powering all electrical loads in the
circuit is to be installed, use the “Total Circuit Isolation Method.” It
is possible for the generator to be overloaded when this isolation
method is employed. The following apply to the transfer switch in
this type of system.
• Ampere rating of the transfer switch must be equal to, or greater
than, the ampere rating of the normal incoming utility service.
• The transfer switch is installed between the utility service
entrance and the building distribution panel.
Installation