Processing Magazine

Tanker-Truck Electronic Grounding System Provides Failsafe Verification

September 14, 2010

The failsafe static grounding system provides confirmation of connection to a static dissipative ground point, and continuous electronic verification of a <10 ohm connection to that point, plus specific tanker truck recognition. The face of the unit features a cluster of bright pulsing green LEDs which provide operators with assurance that a positive ground connection remains in effect throughout the entire transfer operation. This new static grounding system is the tanker-truck specific system for the transfer, processing and handling of various flammable or combustible liquids, gasses and powders. The electronics of the system are protected in a harsh-environment NEMA 4X corrosion-resistant XP enclosure. It provides a certified operating temperature range of -25 to +50 degrees C and significant protection against dust, liquids and weather damage. As an additional feature, the grounding system includes a pair of voltage-free “dry” contacts that energize only when the resistance to the verified ground connection is measured to be 10 ohms or less, allowing a user to demonstrate compliance with the recommendations of globally recognized standards for static control, including NFPA 77, API RP 2003 and Cenelec CLC/TR:50404. The system has North American approval from CSA/US for installation and use in all common hazardous areas, including the very highest gas group approvals: Class I, Div. 1, Groups A, B, C, D; Class II, Div. 1, Groups E, F, G; Class III. Available power units include 110/120 VAC or 220/240 VAC and either 12 or 24 VDC. The units have also been assessed for functional safety and have received an SIL. 2 rating according to IEC 61508 and equivalent ATEX and IECEX approved versions are also available.