ISA 60079-0

This standard specifies the general requirements for construction, test ing and marking of electrical equipment and Ex Components intended for use in explosive atmospheres• Explosive atmospheres are identified by the National Electrical Code®, ANSI/NFPA 70 as hazardous (classified) locations and include the following specified locations:

• Class I, Zone 0

• Class I, Zone 1

• Class I, Zone 2

• Zone 20

• Zone 21

• Zone 22

See 6•1 for the relationship of the Equipment Protection Level (EPL) to the zone area classification•

The standard atmospheric conditions (relating to the explosion characteristics of the atmosphere) under which it may be assumed that electrical equipment can be operated are: