Temperature group of explosion protection rating

Is this temperature calculated based on the ignition temperature of the medium?

Refer to GB 50058-2014

Everything said upstairs is correct; it mainly depends on the ignition temperature of the combustible gas at the site to determine which temperature range applies.

**It is stipulated that electrical equipment intended for use in explosive environments or environments with explosive gases must apply for and obtain an explosion-proof certification for such equipment. Electrical equipment that has obtained an explosion-proof certification is known as explosion-proof electrical equipment. A thermocouple is a type of electrical device. When a thermocouple is used in explosive (gas) environments, it must also obtain an explosion-proof certification; thermocouples that have such certification are known as explosion-proof thermocouples. Explosion-proof thermocouples (resistors) are used to prevent the thermocouple from igniting the explosive gases in an explosive environment, thereby ensuring safe operation. Explosion-proof thermocouples are usually installed using threads or fixed flanges. Structurally, they can be divided into two types: modular type and armored type. The selection of explosion-proof thermocouples (resistors) can be referred to the selection tables for modular thermocouples and armored thermocouples; no further details are provided in this post. In the production sites of petrochemical enterprises, various flammable and explosive chemical gases and vapors are often present; using ordinary thermocouples is extremely unsafe as it can easily lead to explosions caused by these gases. Therefore, flameproof thermocouples must be used as temperature sensors in such situations. The flameproof thermocouples produced by Changhui Instruments are suitable for use in hazardous environments with explosive gases, within temperature ranges corresponding to flameproof ratings of dⅡBT4 or dⅡCT4. Explosion-proof thermocouples: yunrun.com.cn/tech/212.html. How are the explosion-proof markings for explosion-proof thermocouples indicated? ① Ex: The explosion-proof symbol. ② The codes for different explosion-proof types are shown in Table 1: Explosion-proof configuration, Explosion-proof type – Increased safety type, Intrinsic safety type, Positive pressure type, Oil-filled type, Sand-filled type, Encased type; Codes: d, e, ia, ib, p, o, q, m. ③ Explosion-proof categories: Electrical equipment used in explosive gas environments is classified as follows: a. Class I – Electrical equipment for use in coal mines ； b. Class II – Electrical equipment for other explosive gas environments other than coal mines. ④Electrical equipment with explosion protection ratings of Category II, flameproof type “d” and intrinsically safe type “i” is divided into three grades: IIA, IIB, and IIC. ⑤Temperature category refers to the maximum surface temperature of Class II electrical equipment; see Table 2. Temperature category Maximum allowable surface temperature °C T1 450 T2 300 T3 200 T4 135 T5 100 T6 85 Examples of explosion protection markings: ①ExdⅡBT4: Class IIB, explosion-proof, Group T4 ； ②ExdⅡCT5: Class ⅡC flameproof, Group T5 ； ③E*aⅡCT4: Intrinsically safe Type T4 group for Class ⅡC isolators ；

Since we are talking about temperature categories, that refers to gases. Question 1: It is based on the ignition temperature of the medium; for details, see 3.4.2 and Appendix C in GB50058. Question 2: For this, there is no specified design or operating temperature; only the ignition temperature is given. The lowest value among all these ignition temperatures corresponds to the group temperature.

T6 has the best explosion-proof performance, while T1 has the worst. Just remember that. . . The temperature category refers to the level of abnormal heating of the explosion-proof electrical equipment itself; it has nothing to do with what explosive gases are present in the surrounding environment.

I don’t quite agree with what you say. 1. The explosion-proof performance is primarily measured in terms of its explosion-proof design. Temperature groups T1~T6, IIA~IIC are merely a comparison at the same explosion protection level, and are not dominant. 2. The temperature class of electrical equipment is closely related to the explosive gases present in the surrounding environment. For example, the ignition temperature of carbon disulfide is 102°C, and its gas temperature class is T5; therefore, the surface temperature of electrical equipment must not exceed 102°C. The only available temperature classes are T5 or T6

Hehe. 1. Have I mentioned that temperature groups are dominant? 2. You’re really good at distorting the truth about the party and other things :lol 3. One instrument has an explosion protection rating of E*aⅡCT6, while another has a rating of E*aⅡCT5. Compare these two ratings to determine which one is higher; those who understand this first.

Senior, just point out which sentence or phrase has a problem from a technical perspective