The Difference Between Explosion-Proof Level B and C

Class C offers enhanced safety with more meticulous explosion-proof treatment.

Temperature group of electrical equipment	Maximum allowable surface temperature of electrical equipment (℃)	Gas/vapor ignition temperature (℃)	Applicable device temperature levels
T1	450	＞450	T1~T6
T2	300	＞300	T2~T6
T3	200	＞200	T3~T6
T4	135	＞135	T4~T6
T5	100	＞100	T5~T6
T6	85	＞85	T6

Flameproof designs typically feature threading rather than insertable components. Class C devices provide longer flameproof surfaces and narrower explosion gaps. Hydrogen, acetylene, and carbon disulfide necessitate the use of IIC class, whereas other substances are adequately served by IIB class.