The Lighting Systems Division of the National Electrical Manufacturers Association (NEMA), Rosslyn, Va., has introduced a new whitepaper with guidance for grounding when installing outdoor lighting systems. The paper, NEMA LSD 80-2018 Installation Guidelines for Outdoor Luminaires—Grounding Considerations, addresses the application of the National Electrical Safety Code (NESC) as it pertains to the grounding of outdoor luminaires and recommends installation guidelines.
New outdoor luminaries contain more electronics such as LED lamps, electronic drivers and electronic lighting controls than previous outdoor lighting technologies. Electronics are more sensitive to grounding and wiring issues than earlier technologies.
The issue addressed in the whitepaper has to do with whether the neutral and ground conductors are tied together at the luminaire terminals or at the base of the pole.
“When outdoor luminaires used core & coil type ballasts, the luminaire terminal connection did not create any reported issues. With the recent influx of electronics used in such luminaires (e.g., LEDs, electronic drivers, and controls) that are more sensitive to feed connections, new installation guidelines may be appropriate,” said the whitepaper’s introduction.
The six-page document provides five guidelines for installation of outdoor and area lighting:
- It is recommended that luminaires be provided with a ground terminal electrically separate from the ungrounded (neutral) conductor.
- The luminaire ground terminal may be a separate grounding conductor or a provision for luminaire chassis ground.
- In installations where non-metal posts or poles are used, consideration needs to be given to providing a dedicated ground conductor or luminaire chassis ground.
- Existing installations that are not exhibiting any problems need not be reconfigured.
- If an existing luminaire with neutral to ground connection at the luminaire terminals is to be repurposed, it must not be connected to a supply voltage that does not have a neutral reference.
“This whitepaper offers guidelines on proper grounding techniques to improve outdoor luminary performance,” said Michael O’Boyle, technical policy manager for lighting manufacturer Signify.
NEMA LSD 80-2018 is available as an electronic download at no cost on the NEMA website.