Site Selection and Preparation
14
Installation Guidelines for Air-Cooled Generators
Install the generator outdoors in its protective enclosure where adequate cooling and ventilating air is always available.
Also consider these other factors:
•
Installation must strictly comply with NFPA 37, NFPA 54, NFPA 58, and NFPA 70 standards.
•
Install the generator where air inlet and outlet openings will not be obstructed by leaves, grass, snow, etc. If pre-
vailing winds can cause blowing or drifting, use a windbreak for protection.
•
Install the generator on high ground where rising water levels will not endanger it. The generator must not oper-
ate in or be subjected to standing water.
•
Allow sufficient room on all sides of the generator for maintenance and servicing. Install the unit in accordance
with current applicable NFPA 37 and NFPA 70 standards, as well as any other federal, state and local codes for
minimum distances from other structures. DO NOT install under wooden decks or structures unless there is at
least 5 feet (1.52 m) of clearance above the generator, 3 feet (0.91 m) of clearance at sides and front, and a min-
imum of 18 inches (457 mm) of clearance at the back of the unit.
•
Install where rain gutter down spouts, roof run-off, landscape irrigation, water sprinklers or sump pump discharge
does not flood, spray, or splash the enclosure, particularly air inlet or outlet openings.
•
Install where services will not be affected or obstructed, including concealed, underground or covered services
such as electrical, fuel, phone, air conditioning or irrigation. This could affect Warranty Coverage.
•
Where strong prevailing winds blow from one direction, face the generator air inlet openings to the prevailing
winds.
•
Install the generator as close as possible to the fuel supply source to reduce the length of piping required.
REMEMBER THAT LAWS OR CODES MAY REGULATE THE DISTANCE AND LOCATION.
•
If applicable, install the generator as close as possible to the transfer switch. REMEMBER THAT LAWS OR
CODES MAY REGULATE THE DISTANCE AND LOCATION.
•
Install the generator on a level surface. The generator must be level within a 0.5 inches (13mm) all around.
•
The generator is typically placed on a concrete pad, compacted pea gravel, or crushed stone. Check local codes
to see what type is required. If a concrete pad is required, follow all federal, state and local codes.
3.1.1— Installation Guidelines
The National Fire Protection Association has a standard for the installation and use of stationary combustion engines.
That standard is NFPA 37, its requirements limit the spacing of an enclosed generator set from a structure or wall (Fig-
ure 1.10).
NFPA 37, Section 4.1.4, Engines Located Outdoors: Engines, and their weatherproof housings if provided, that are
installed outdoors shall be located at least 5 ft (1.52 m) from openings in walls and at least 5 ft (1.52 m) from structures
having combustible walls. A minimum separation shall not be required where either of the following conditions exist:
1.
The adjacent wall of the structure has a fire resistance rating of at least 1 hour.
2.
The weatherproof enclosure is constructed of noncombustible materials and it has been demonstrated that a fire
within the enclosure will not ignite combustible materials outside the enclosure.
Annex A — Explanatory Material
A4.1.4 (2) Means of demonstrating compliance are by means of full scale fire test or by calculation procedures.
Because of the limited spaces that are frequently available for installation, it has become apparent that exception (2)
would be beneficial for many residential and commercial installations. With that in mind, the manufacturer contracted
with an independent testing laboratory to run full scale fire tests to assure that the enclosure will not ignite combustible
materials outside the enclosure.
NOTE: Southwest Research Institute testing approves 18 inches (457 mm) installation minimum from struc-
ture. Southwest Research is a nationally recognized third party testing and listing agency.
The criteria was to determine the worst case fire scenario within the generator and to determine the ignitability of items
outside the engine enclosure at various distances. The enclosure is constructed of non-combustible materials, and the
results and conclusions from the independent testing lab indicated that any fire within the generator enclosure would
not pose any ignition risk to nearby combustibles or structures, with or without fire service personnel response.
