New UL Safety Standards Mean Changes for Specifiers

By Consulting Specifying Engineer Staff April 18, 2006

White Paper by: Pass & Seymour/Legrand

When the first ground fault circuit interrupter was invented in 1971, it revolutionized the electrical industry, reducing electrocutions by protecting building occupants from lethal ground faults. Today GFCIs have evolved from safety enhancements to necessities, required to be installed in every building, from homes and offices to health-care facilities and entertainment complexes. As GFCIs continue to develop, they are paving the way for greater safety standards—and 2006 will bring the most stringent requirements ever.

A GFCI de-energizes a circuit when a current to ground could result in electric shock. The GFCI “interrupts” power before it reaches a level that would cause injury.

GFCIs have become great life saving devices, with reliable performance records.However, some of their electrical components can fail over time or with exposure to tough environments.

To ensure the development of even better GFCIs, Underwriters Laboratories (UL), the world’s foremost product safety and certification organization, revised

UL 943 — Safety Standard for Ground Fault Circuit Interrupters (GFCIs). The revisions demand that each new GFCI offers miswire protection and end-of-life indication. The standards are set to take effect on July 28, 2006 and include the following requirements:

End of Life Provision: A GFCI receptacle is incapable of passing its internal test function (it can no longer provide ground fault protection) it will either a) render itself incapable of delivering power, or b) indicate by visual or audible means that the device must be replaced.

Reverse Line-Load Miswire: A GFCI will deny power to the receptacle face if it is miswired.

These regulations will likely have profound effects on the industry. As of July 28, manufacturers must stop producing old versions of GFCIs and must introduce redesigned GFCIs after that date. Current GFCI can be used as long as supplies last.

Specifiers should be aware of the UL standards and incorporate them in all of their designs. All specifications should be revised to include the new safety requirements and new catalog numbers.

To ease the transition some manufacturers have finalized their new product lines early. Pass & Seymour/Legrand will begin selling its fully redesigned GFCIs in May 2006, with some unique features that meet the new requirements and provide additional security.

“A surge is the number one failure mode for a GFCI, and UL requires GFCIs to withstand 20 3,000-amp/6,000-volt voltage surge test cycles,” said Bill Timmons, P&S Marketing Manager. “Our GFCIs can survive 2,000 surge test cycles — 100 times the UL standard.”

The UL revisions will not affect the NEC, which regulates installations, not products. More information on the UL revisions can be found through the Electrical Safety Foundation International .