Special-Purpose Ground-Fault Circuit Interrupter (GFCI), Class C and Class D
Industrial Shock Block (ISB) is a personnel protection device designed to meet the requirements for special-purpose GFCIs defined by UL 943C. This standard outlines GFCI classes specifically designed for use in industrial facilities. Class C GFCIs are intended to be used on three-phase systems where the line-toline voltage is 480 V or less with a trip level of 20 mA, while Class D GFCIs are intended to be used on 600 V systems. The Industrial Shock Block includes an automatic self-test feature and is compliant to the UL 1998 Software in Programmable Components standard.
Ground-Fault Circuit Interrupter (GFCI), Class A
The Shock Block is available as a Class A GFCI, allowing commercial kitchens, construction sites, and other non-dwelling units with wet areas to meet NEC 210.8(B) for their 3-phase loads up to 100 A.
Equipment Ground-Fault Protective Device (EGFPD)
Industrial Shock Block is also available with adjustable protection settings as an EGFPD. The EGFPD models can be set to trip at 6 mA or from 10-100 mA in increments of 10 mA. This offers more flexibility since GFCI devices are not allowed to have an adjustable trip level.
Rating and Models
Industrial Shock Block (GFCI & EGFPD) is available for three-phase voltages from 208 to 600 V with a maximum full load current of 100 A, and a built-in overcurrent protection supplied by Littelfuse Class T fuses. The power system can be either solidly or high-resistance grounded and the load must be three phase without a neutral.