Color Changes: Low Voltage Wiring

The National Electrical Manufacturers Association (NEMA) is an organization that develops the technical standards for the manufacturing of electrical equipment and medical imaging equipment. They work to set industry standards for safety, innovation, interoperability, environment, and market enhancement of our industry. NEMA has clarified guidance on the color used for low voltage control wires which excludes the use of grey wiring 0-10V controls. Instead, NEMA designated violet (purple) and pink to be the standard colors moving forward. This new requirement went into effect January 1, 2022.

“Dimming control via 0-10V has been a means of dimming lighting for decades. This goes back to fluorescent dimming ballasts and consisted of a pair of wires with grey and violet insultation,” explains Dan Kohen, Director of Commercialization at H.E. Williams. “With the advent of LED, nearly all luminaires produced today are dimmable and most commonly use 0-10V as its method.” He continues, “The National Fire Protection Association (NFPA), writers of the National Electric Code (NEC), started to grow concerned about the potential confusion and conflict between the grey insulated low-voltage control wires, and grey neutral branch circuit wires. NEC 200.6(A) allows for grounded, neutral conductors to be grey. As a result, NEC made an update to the 2020 code, not specifying what colors these low-voltage conductors could be, but instead specifying what colors they can’t.”

This color change is a step in the right direction for consistency in the industry. In addition to decreasing the risk of serious injury from miswiring mistakes, older installations are now easily identifiable by their grey 0-10V wires. For more information on low voltage wiring and lighting and controls code updates, contact your local team of experts at Mercer Zimmerman.

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