Ground 07 : A conducting connection, whether intentional or accidental, between an electrical circuit or equipment and the earth or to some conducting body that serves in place of the earth
EESiFlo North America, Terminology and Glossary: Explosion Proof & Hazardous Areas, Pennsylvania, USA 2002, flowmeterdirectory.com/flowmeter_terminology, (Mrtm/ Explo Proof and Haz Areas - Amer) {561}