Generac Power Systems 004812-3, Owner'S Manual

Page: 10 / 110

8
Section 2 – Installation
Standby Generator Sets
NOTE:
For more information about the installation of a
standby system, order
Engine-Generator Standby
Electric Power Systems, Installer’s Guide and
Reference Manual (part #046622
) from an
Authorized Service Dealer.
2.1.1 NFPA STANDARDS
The following published standards booklets pertain-
ing 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 informa-
tion 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, New York, N.Y.
10018.
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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 GENERATOR (STANDBY) output are
connected to an approved transfer switch. The trans-
fer 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.
Figure 2.1 – Basic Standby Electric System
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 gen-
erator.
2.3 EMERGENCY CIRCUIT ISOLATION
METHOD
This prevents overloading the generator by keeping
electrical loads below the wattage/amperage capac-
ity of the generator. If the generator is powering only
critical loads, within the wattage/amperage capac-
ity, during utility power outages, consider using the
emergency circuit isolation method.
Critical electrical loads are grouped together and
wired into a separate “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: