Some good news regarding GFCIs.

kurt · November 8, 2013

Industrial GFCIs Are Finally Here November 07, 2013

Industrial GFCIs Are Finally Here

Contributed Article
Special to Mike Holt Enterprises Electrical News Source
October, 2013

Everyone is familiar with ground fault circuit interrupters (GFCIs). We see them in our bathrooms and kitchens at home, where they protect us from electric shock by quickly interrupting the circuit as soon as a ground fault is detected. Simple and reliable, this technology is credited with cutting residential electrocutions in half since it was mandated by the NEC in the 70s.

A different story can be told about the workplace. From 1992-2002, there were 3,348 electrocutions on the job. Despite higher voltages in the workplace that increase the danger of shock, only recently has GFCI technology become available for industrial and commercial settings. The first UL Listed GFCI for applications up to 600 V became available last year.

What is an Industrial GFCI?
An industrial GFCI (UL calls it a “special purpose” GFCI) operates like any other, except for some important differences. First, the trip threshold is set at 20 mA, higher than its residential cousin. Second, the GFCI device must monitor the ground wire for open connections, so that if the connection to ground is lost, then the device will open the circuit. Third, an industrial GFCI interrupts higher power, so it must be much larger. It mounts like an electrical panel or inside an existing electrical cabinet.

According to the UL 943 standard, Class A GFCIs (for use on circuits up to 240 V) must trip at 6 mA. Unfortunately these devices cannot be used in industrial facilities, which typically have significant ground leakage currents that would cause nuisance tripping.

In 2000, UL addressed GFCIs for higher voltage applications with a draft standard “Outline of Investigation” called 943 C and added to it in 2009, but no commercially available product could pass its test requirements until recently. UL 943C Class C, Class D, and Class E define the characteristics expected of a GFCI operating up to 600 V.

Class C – For circuits with no conductor over 300 VAC to ground where reliable equipment grounding or double insulation is provided.
Class D – For in circuits with one or more conductors over 300 volts to ground, and with specially sized, reliable grounding, to provide a low impedance path so that the voltage across the body during a fault does not exceed 150 volts.
Class E – For circuits with one or more conductors over 300 volts to ground but with conventional equipment grounding provided for the protected equipment in the system or double insulation. These devices respond rapidly to open the circuit.
Why the 20mA trip threshold?
UL 943C sets the trip threshold of industrial GFCIs at 20 mA — low enough to provide worker shock protection but high enough in most applications to avoid nuisance tripping. Like household GFCIs, their response to ground current follows an inverse-time curve; a current of 20 mA will cause a trip in about 1 s (quickly enough to prevent injury at this current level), and higher currents will cause a trip within 20 ms.

In some cases, the 20 mA trip threshold may still cause nuisance tripping. One option is an equipment ground-fault protection device (EGFPD), which is like a GFCI except it has adjustable trip settings from 6 to 50 mA. Although EGFPDs protect workers against shock, UL lists them in a category for equipment protection rather than for people protection.

Where are industrial GFCIs used?
Wet applications deserve scrutiny, because water can increase the risk of shock by bringing workers into contact with a ground fault. Industrial GFCIs can be applied to submersible pumps, wet saws, and process equipment such as augers and mixers that handle wet material. Review damp or wet work areas, such as those found in food processing facilities, and areas where equipment is subjected to washdown cleaning.

Industrial GFCIs can be mounted on a wheeled cart and used to protect temporary applications, especially outdoors where electrical equipment is exposed to moisture.

Also consider any application wet or dry where workers come into contact with equipment operating at high voltage, such as welding receptacles.

Long overdue
This is a safety technology that has been long overdue. Now that UL Listed industrial GFCIs are available, the adoption of such protection will grow. Industrial GFCIs are not required by the electrical code, but if the history of residential GFCIs are a model, then the code may be updated to require GFCIs in more industrial applications.

More information is available in a white paper from Littelfuse: http://www.littelfuse.com/~/media/Fi...WhitePaper.pdf

Media Contact: Mark Johnson
Goldstein Group Communications
440-914-4700
mjohnson@ggcomm.com

This newsletter was sent to 31060 Subscribers

Worth1 · November 8, 2013

All throughout my garge I put in gfci protection and piggybacked the other receptacles off of them.
The only things that aren't on them are the freezer and refrigerators which aren't required.
You don't want them tripping out.

Other than that the article is a little over the general publics head.
Like how many people know that 20 ma is 20 thousands of an amp?

There's a lot going on with this that many folks don't know they just want their coffee pot to work.
They even have breakers that take the place of gfci outlets now.

Worth

November 8, 2013	#1
kurt Tomatovillian™ Join Date: Oct 2011 Location: Homestead,Everglades City Fl. Posts: 2,500	Some good news regarding GFCIs. Industrial GFCIs Are Finally Here November 07, 2013 Industrial GFCIs Are Finally Here Contributed Article Special to Mike Holt Enterprises Electrical News Source October, 2013 Everyone is familiar with ground fault circuit interrupters (GFCIs). We see them in our bathrooms and kitchens at home, where they protect us from electric shock by quickly interrupting the circuit as soon as a ground fault is detected. Simple and reliable, this technology is credited with cutting residential electrocutions in half since it was mandated by the NEC in the 70s. A different story can be told about the workplace. From 1992-2002, there were 3,348 electrocutions on the job. Despite higher voltages in the workplace that increase the danger of shock, only recently has GFCI technology become available for industrial and commercial settings. The first UL Listed GFCI for applications up to 600 V became available last year. What is an Industrial GFCI? An industrial GFCI (UL calls it a “special purpose” GFCI) operates like any other, except for some important differences. First, the trip threshold is set at 20 mA, higher than its residential cousin. Second, the GFCI device must monitor the ground wire for open connections, so that if the connection to ground is lost, then the device will open the circuit. Third, an industrial GFCI interrupts higher power, so it must be much larger. It mounts like an electrical panel or inside an existing electrical cabinet. According to the UL 943 standard, Class A GFCIs (for use on circuits up to 240 V) must trip at 6 mA. Unfortunately these devices cannot be used in industrial facilities, which typically have significant ground leakage currents that would cause nuisance tripping. In 2000, UL addressed GFCIs for higher voltage applications with a draft standard “Outline of Investigation” called 943 C and added to it in 2009, but no commercially available product could pass its test requirements until recently. UL 943C Class C, Class D, and Class E define the characteristics expected of a GFCI operating up to 600 V. Class C – For circuits with no conductor over 300 VAC to ground where reliable equipment grounding or double insulation is provided. Class D – For in circuits with one or more conductors over 300 volts to ground, and with specially sized, reliable grounding, to provide a low impedance path so that the voltage across the body during a fault does not exceed 150 volts. Class E – For circuits with one or more conductors over 300 volts to ground but with conventional equipment grounding provided for the protected equipment in the system or double insulation. These devices respond rapidly to open the circuit. Why the 20mA trip threshold? UL 943C sets the trip threshold of industrial GFCIs at 20 mA — low enough to provide worker shock protection but high enough in most applications to avoid nuisance tripping. Like household GFCIs, their response to ground current follows an inverse-time curve; a current of 20 mA will cause a trip in about 1 s (quickly enough to prevent injury at this current level), and higher currents will cause a trip within 20 ms. In some cases, the 20 mA trip threshold may still cause nuisance tripping. One option is an equipment ground-fault protection device (EGFPD), which is like a GFCI except it has adjustable trip settings from 6 to 50 mA. Although EGFPDs protect workers against shock, UL lists them in a category for equipment protection rather than for people protection. Where are industrial GFCIs used? Wet applications deserve scrutiny, because water can increase the risk of shock by bringing workers into contact with a ground fault. Industrial GFCIs can be applied to submersible pumps, wet saws, and process equipment such as augers and mixers that handle wet material. Review damp or wet work areas, such as those found in food processing facilities, and areas where equipment is subjected to washdown cleaning. Industrial GFCIs can be mounted on a wheeled cart and used to protect temporary applications, especially outdoors where electrical equipment is exposed to moisture. Also consider any application wet or dry where workers come into contact with equipment operating at high voltage, such as welding receptacles. Long overdue This is a safety technology that has been long overdue. Now that UL Listed industrial GFCIs are available, the adoption of such protection will grow. Industrial GFCIs are not required by the electrical code, but if the history of residential GFCIs are a model, then the code may be updated to require GFCIs in more industrial applications. More information is available in a white paper from Littelfuse: http://www.littelfuse.com/~/media/Fi...WhitePaper.pdf Media Contact: Mark Johnson Goldstein Group Communications 440-914-4700 mjohnson@ggcomm.com This newsletter was sent to 31060 Subscribers __________________ KURT

November 8, 2013	#2
Worth1 Tomatovillian™ Join Date: Feb 2006 Location: Den of Drunken Fools Posts: 38,539	All throughout my garge I put in gfci protection and piggybacked the other receptacles off of them. The only things that aren't on them are the freezer and refrigerators which aren't required. You don't want them tripping out. Other than that the article is a little over the general publics head. Like how many people know that 20 ma is 20 thousands of an amp? There's a lot going on with this that many folks don't know they just want their coffee pot to work. They even have breakers that take the place of gfci outlets now. Worth