The Difference Between Explosion-Proof Level BT6 and BT4

The ‘B’ classification denotes the approved level of equipment for handling gases and vapors within a facility, typically used for substances like ethylene, dimethyl ether, and coke oven gas.

Temperature Classification for Electrical Equipment	Maximum Permissible Surface Temperature of Electrical Equipment (°C)	Gas/Vapor Ignition Temperature (°C)	Applicable Equipment Temperature Class
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

The ‘T’ category specifies temperature groups, where T4 equipment has a maximum surface temperature of 135°C, and T6 equipment maintains a maximum surface temperature of 85°C.

Since T6 equipment operates at a lower surface temperature compared to T4, it reduces the likelihood of igniting explosive gases. Consequently, BT6 is superior to BT4.