Explosion protection rating: Zone II, Class B, Group T4
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Please ask Haiyou from the electrical department to explain to me what the explosion protection rating of Zone II, Class B, Group T4 specifically means
Group IIA: Atmospheric environments containing propane or gases or vapors with equivalent hazard. Group IIB: Atmospheric environments containing ethylene or gases or vapors with equivalent hazard. Group II C: Atmospheric environments containing acetylene, hydrogen, or gases or vapors with equivalent hazard levels. ICE temperature codes: Temperature code, Maximum surface temperature, °C, °F. T1: 450, 842; T2: 300, 572; T3: 200, 392; T4: 135, 275; T5: 100, 212; T6: 85, 185
Got it, thank you: Explosion protection type d (flameproof) + Equipment category II (electrical equipment for industrial use) + Gas group B (maximum safe gap MESG between 0.9 and 0.5, minimum ignition current ratio MICR between 0.8 and 0.45) + Temperature group T4 (the highest surface temperature of the equipment is 135°C, and the ignition temperature of flammable substances is between 200°C and 135°C)
Definition of explosion-proof equipment: Electrical equipment that will not cause ignition in the surrounding explosive environment under specified conditions. Category I: Coal mines, underground electrical equipment； Class II: All electrical equipment for explosive gas environments other than coal mines and underground areas. Category II can be further divided into IIA, IIB, and IIC; devices designated as IIB can be used under the same conditions as IIA devices ； ⅡC can be applied under the same conditions as ⅡA and ⅡB. Note: The IIC mark indicates a higher level of explosion protection, but it does not mean that the device has the best performance. Maximum surface temperature: The highest temperature reached by any component of an electrical equipment that could cause ignition in an explosive environment surrounding it, when the equipment is operating under the most unfavorable conditions within its specified range. The maximum surface temperature should be below the flammability temperature. For example: if the ignition temperature of the explosive gas in the environment surrounding the explosion-proof sensor is 100°C, then under the most severe operating conditions, the highest surface temperature of any component of the sensor should be below 100°C. Temperature categories: Electrical equipment for explosive environments is classified into groups T1–T6 based on its maximum surface temperature. T1: 450 °C; T2: 300 °C; T3: 200 °C; T4: 135 °C; T5: 100 °C; T6: 85 °C℃