GFCIs FOR COMMERCIAL AND INDUSTRIAL APPLICATIONS Prevention through Design with Special-Purpose GFCIs TECHNICAL PAPER

PREVENTION THROUGH DESIGN WITH SPGFCIs With power, comes great responsibility. Companies must never take electrical shock lightly, or believe that safety training and PPE are enough on their own. Hundreds of workers are killed every year from electrical shock1. More than 90 % of electrical fatalities among US workers are due to electrical shock, and tens of thousands of electrical shock incidents over the years have resulted in injuries that require time away from work. alternating current Bureau of Labor Statistics direct current EGFPD equipment ground-fault protection device GFCI HRG This paper...

PREVENTION THROUGH DESIGN WITH SPGFCIs Many factors affect the current’s ability to pass through the body, and it only takes about 6 mA (for the average female) and 9 mA (for the average male) to reach the “let-go threshold,” which when the current causes the muscles to uncontrollably contract and renders the victim unable to let go and break from the current on their own (see Figure 1). Unfortunately, this ability to let go (and thus break from the electrical current) will often make the difference between life and death. Alternating current (ac) repetitively stimulates nerves and muscles that...

PREVENTION THROUGH DESIGN WITH SPGFCIs Most Effective DE-ENERGIZE EQUIPMENT Elimination Substitution GFCIs SAFETY TRAINING Least Effective Engineering Controls Administrative Controls GLOVES, RUBBER MATS AND RUBBER TOOLS FIGURE 3. The Hierarchy of Controls. Prevention through Design: GFCI Electrical Shock Prevention The longer the current lasts, the greater the injury. A person who has passed the let-go threshold is physically incapable of breaking from the current on their own. At this point, the current will not stop traveling through their body until it is interrupted by a GFCI or similar...

PREVENTION THROUGH DESIGN WITH SPGFCIs physical strength, flexibility and durability for them to remain effective. Whether the worker ultimately wears them is a different story. To learn more about why PPE and safety training are dangerous mitigation methods to rely upon, read The State of Electrical Shock Safety survey report. How GFCIs Work GFCIs eliminate shock hazards by cutting off power when even the slightest amount of current flows where it should not. If a person touches a live GFCI-protected conductor, the GFCI will open the circuit before the shock incident becomes lethal. A single-phase...

PREVENTION THROUGH DESIGN WITH SPGFCIs All special-purpose GFCIs must have a minimum trip rating of 15 to 20 mA, but Class C devices are permitted to have a trip threshold as low as 6 mA. In addition, UL 943C requires the GFCI to monitor the continuity of the ground wire and interrupt power to the load if ground integrity is lost.  Class C GFCIs: for use in circuits with no conductor over 300 V to ground where reliable equipment grounding or double insulation is provided. Class C GFCIs interrupt the circuit when the ground-fault current is between 15 mA and 20 mA. They have trip thresholds between...

PREVENTION THROUGH DESIGN WITH SPGFCIs Proactive GFCIs Detect Ground Faults and Protect Against Fatal Shocks with One Device Ground check tremendously increases safety. Ground check monitors the continuity of the grounding circuit, causing the power conductors to be de-energized if ground continuity is lost. Ground conductor monitoring enhances the standard protection of a GFCI by taking proactive measures. A ground check feature provides this by not allowing energization to a load with improper grounding, and de-energizing any circuit where the grounding becomes compromised under load. By decreasing...

PREVENTION THROUGH DESIGN WITH SPGFCIs A good EGFPD will have an adjustable sensitivity, which is usually between 6 mA and 100 mA. This enables the sensitivity to be adjusted to the lowest sensitivity level that is above the base leakage current. Doing so creates the safest possible conditions for workers in environments where worker protection at 20 mA is not possible. Littelfuse EGFPDs can also monitor the ground conductor, which— though not required by UL 943C—provides an additional layer of protection. against electrical shock. Ground-fault relays do not open the affected circuit themselves....

PREVENTION THROUGH DESIGN WITH SPGFCIs The non-residential locations that NEC 210.8(B) requires GFCI protection include:  Bathrooms  Kitchens or areas with a sink and permanent provisions for either food preparation or cooking  Rooftops  Outdoors  Sinks—where receptacles are installed within 1.8 m (6 ft) from the top inside edge of the bowl of the sink  Indoor damp and wet locations  Locker rooms with associated showering facilities  Garages, accessory buildings, service bays, and similar areas other than vehicle exhibition halls and showrooms  Crawl spaces at or below grade level  Unfinished...

ELECTRICAL SAFETY BY DESIGN WITH SPGFCI PREVENTION THROUGH DESIGN WITH SPGFCIs Industry-Specic Challenges and Solutions To electrical panel FIGURE RESTAURANT. XXXXXXX 1 Drop-Down Receptacles for Prep 3 Electric Oven/Pizza Oven FIGURE RESTAURANT FIGURE 5. The SB5000, a Class A GFCI, allows restaurants to meet new NEC requirements without making it difficult to also meet health and sanitation codes. GFCIs Designed for the Entertainment Industry and Temporary Installations  A lack of proper ground conductors  Improperly protected conductors (i.e., lack of There are three different types of rental...

PREVENTION THROUGH DESIGN WITH SPGFCIs The rental Class A Littelfuse Shock Block is a GFCI designed to protect workers in the entertainment industry, who often encounter wet conditions and cables with worn insulation. The entertainment industry and Hollywood sets often use portable GFCIs (such as the Shock Block GFCI) that have these specific features critical for onset usage such as:  A rugged outer cage  Connectors that fit pre-existing equipment (like Bates connectors) for Hollywood on-set equipment  Compatibility with three-phase 4-wire systems  Meets UL requirements for portable applications...