Division into temperature classes
Explosion proof equipment, installed within an Ex area, is divided into 6 temperature classes (T1 to T6). The temperature class is not – as it is often wrongly believed – the operating temperature range of the equipment, but the maximum permissible surface temperature of the equipment, in relation to + 40°C ambient temperature on any surface area, which may not be exceeded at any time. The maximum surface temperature must remain below the ignition temperature of the surroun-
ding medium at all times. The equip-
ment design requirements increase from T1 to T6.