NECA NEIS 406
Standard for Installing and Maintaining Residential Generator Sets
|Publication Date:||1 January 2014|
Products and Applications Included
This standard describes installation and maintenance procedures for residential generators fueled by gasoline, natural gas, or liquefied petroleum gas (LP or propane) and permanently installed at one-family dwellings to provide backup power. Residential generators are usually rated 240/120 volts, singlephase, three-wire. Some larger one-family dwellings have three-phase electrical systems and may use backup generators rated 208Y/120 volts, three-phase, four-wire.
This standard also covers the installation of related items such as non-automatic (manual) or automatic transfer switches (MTS or ATS), disconnect switches, control panels, and fuel supply systems, and describes some electrical power distribution system design consideration related to the use of generators to supply important, non-emergency loads in singlefamily dwellings.
Residential generators are considered to be "optional standby power systems" in accordance with the NEC.
Products and Applications Excluded
This standard does not cover installation or maintenance procedures for:
• Generators defined as "emergency systems" or "legally-required standby systems" intended to supply power for emergency or life-safety applications in accordance with NFPA 70, National Electrical Code.
• Generators that supply other types of buildings or facilities, including two-family and multifamily dwellings. These applications are addressed by NECA/EGSA 404, Standard for Installing Generator Sets (ANSI).
• Diesel-powered generators, which are addressed by NECA/EGSA 404, Standard for Installing Generator Sets (ANSI).
• Marine or vehicle-mounted generators.
• Portable generators. Portable generators are typically supplied from the manufacturer with an inaccessible internal neutral-to-ground bonding jumper connected from the neutral point of the generator winding to the frame of the generator. GFCI protection required for portable generators is de-sensitized by multiple neutral-to-ground bonds, such as at service equipment and at a portable generator.
Regulatory and Other Requirements
a) All information in this publication is intended to conform to the National Electrical Code® (ANSI/ NFPA Standard 70). Installers should always follow the NEC®, applicable state and local codes, and manufacturer's instructions when installing electrical equipment and systems.
b) Only qualified persons as defined in the NEC familiar with the construction and installation of electrical power distribution and control systems and equipment should perform the technical work described in this publication. Administrative functions and other tasks can be performed under the supervision of a qualified person. All work should be performed in accordance with NFPA 70E, Standard for Electrical Safety in the Workplace (ANSI).
c) General requirements for installing electrical products and systems are described in NECA 1, Standard for Good Workmanship in Electrical Construction (ANSI). Other National Electrical Installation Standards provide additional guidance for installing particular types of electrical products and systems. A complete list of NEIS is provided in Annex E.