ABSTRACT
This chapter explains the principles of the main techniques for protecting against electrical and electrostatic ignition. It covers flammable gas/air mixtures, with the risks associated with explosions in dust-laden atmospheres considered on. The potential for electrostatic discharges and electrical equipment installed in locations where there are flammable and explosive atmospheres to act as an ignition source has long been recognised. The intention is to explain what needs to be done to control the risk of ignition from electrical equipment and electrostatic discharge. Engineers responsible for selecting electrical apparatus for installation in a hazardous area will need to know into which Gas Group the flammable atmosphere in each hazardous area will fall. There are two main groups: Group one, which relates to electrical apparatus for use in mines susceptible to firedamp; and Group two, which relates to electrical apparatus for use in places where an explosive gas/air atmosphere exists, other than mines susceptible to firedamp.
