The Earthing Relay Model ERX-710 is an Intrinsically Safe field-protection device used in Vehicle Static Grounding Systems. It provides the operator with absolute confirmation that the Vehicle is properly earthed and is consequently safe for loading or unloading operations. The instrument thus ensures safety during the loading and handling of volatile chemicals or inflammable liquids at truck, rail and aircraft refueling terminals.
Transport Vehicles, particularly of inflammable, explosive or sensitive material should be necessarily grounded before, as well as during, any loading or unloading operation. One of the primary causes of fire and explosions during such operations is the danger of accidental sparking which may be caused by the generation of a high static-charge on the body surface or chassis of the vehicle. Since the tyres of the vehicle are made of a non-conductive material, there is no path available for the discharge of this developed static-charge. On entry at the loading / unloading terminal, the Tanker is first earthed to the “true-Earth” (Ground) point by means of a Clamp Probe and the static-charge is dissipated. Even a low level residual static-charge could result in minor sparking on contact with any metallic dispensing hose or valve, which could spell disastrous repercussions in a hazardous area. The Earthing Relay ensures that this residual charge is dissipated through an internal shunt route, and then re-checks to ensure ground potential of the truck body.
The instrument has been tested and certified for Intrinsic Safety by The Central Mining Research Institute (CMRI) at Dhanbad for suitability of operation in Gas Groups IIA and IIB. The Earthing Relay Card itself is housed in an explosion-proof enclosure, which is certified for operation in Gas groups II-A and II-B by CMRI Dhanbad and CCOE, Nagpur.
All ASHE instruments carry a lifetime warranty against defects in components and workmanship.