ZONE CLASSIFICATION

ZONE CLASSIFICATION: BASIS FOR RISK ASSESSMENT

Potentially explosive atmospheres are classified into zones in order to facilitate the selection of appropriate electrical equipment as well as to design suitable electrical installations. The zone classification reflects the probability of the occurrence of an explosive atmosphere.

The maximum risk potential for each area must be taken into account when dividing the potentially explosive areas into zones and determining the necessary protective measures. If the company does not have a suitable person to carry out the risk assessment and determine suitable measures, an authority must be deployed for it.

ZONE CLASSIFICATION FOR GAS

Zone 0* defines an area in which a hazardous explosive atmosphere as a mixture of air and combustible gases, vapours or mists is present continuously, for long periods or frequently.

Zone 1* describes an area in which a hazardous explosive atmosphere as a mixture of air and combustible gases, vapours or mists is likely to occur under normal operating conditions.

Zone 2* refers to an area in which a hazardous explosive atmosphere as a mixture of air and combustible gases, vapours or mists is normally not present, or is only present for a short period of time, under normal operating conditions.

Zone classification for DUST

Zone 20* defines an area in which a hazardous explosive atmosphere in the form of a cloud containing combustible dust in air is present continuously, for long periods or frequently.

Zone 21* describes an area in which a hazardous explosive atmosphere in the form of a cloud containing combustible dust in air is likely to occur under normal operating conditions.

Zone 22* refers to an area in which a hazardous explosive atmosphere in the form of a cloud containing combustible dust in air is normally not present, or is only present for a short period of time, under normal operating conditions.