On regular explosion-proof electrical equipment, there will be an Ex mark, and each explosion-proof electrical equipment will have a unique oneExplosion proof markTaking the following explosion-proof signs as an example:
Note 1: Ex is the explosion-proof mark of China and the International Electrotechnical Commission, indicating that electrical equipment complies withGB3836One or more explosion-proof types listed in IEC60079
Note 2: Common explosion-proof type symbols are as follows:
Explosion proof type“d”、 Increased safety type "e"Intrinsic safety type“i”、 Filling sand mold "q"Positive pressure type“p”、 Liquid immersion type "o", "n"exm“m”
The explosion-proof symbol in the example is for explosion-proof electrical equipment
Note 3: Equipment Category Symbols
(1) Class I: Electrical equipment used in coal mines that are prone to gas generation
(2) Class IIA, IIB, and IIC: Electrical equipment used in explosive gas environments other than Class I, i.e. factory electrical equipment
Note: Equipment IIB can be used for the usage conditions of equipment IIA, and similarly, equipment IIC can be used for the usage of equipment IIA and IIB; Condition, therefore, explosion-proof level IIC>IIB>IIA
Note 4: For Class II electrical equipment, the symbols representing temperature groups are as follows:
The highest surface temperature group for Class II electrical equipment
| Temperature group |
Maximum surface temperature (° C) |
| T1 |
450 |
| T2 |
300 |
| T3 |
200 |
| T4 |
135 |
| T5 |
100 |
| T6 |
85 |
Note 5: The device protection level is divided into "Ga", "Gb", "Gc", "Ma" or "Ma".
Equipment Protection Level (EPL): A fixed protection level for equipment based on its potential to become an ignition source and the different characteristics of explosive gas environments, explosive dust environments, and coal mine methane explosive environments.
——Ma level (EPL Ma): Equipment installed in the explosive environment of methane in coal mines, with a "very high" level of protection. This level has sufficient safety, making it impossible for the equipment to become an ignition source during normal operation, in the event of expected or rare failures, or even when the equipment is still charged due to the sudden appearance of gas.
——Mb level (EPL Mb): Equipment installed in coal mine methane explosive environments with a "high" protection level, which has sufficient safety to prevent the equipment from becoming an ignition source under expected fault conditions during normal operation or between sudden gas occurrence and equipment power failure.
——Ga level (EPL Ga): Equipment used in explosive gas environments, with a "very high" protection level, and is not an ignition source in normal operation, expected faults, or rare faults.
——Gb level (EPL Gb): Equipment used in explosive gas environments, with a "high" protection level, and is not an ignition source under normal operation or expected fault conditions.
——Gc level (EPL Gc): Equipment used in explosive gas environments, with a "general" protection level, is not an ignition source during normal operation, and additional protective measures can be taken to ensure that effective ignition does not occur in situations where the ignition source is expected to frequently occur (such as lamp failure).
——Da level (EPL Da): Equipment used in explosive dust environments, with a "very high" protection level, and is not an ignition source in normal operation, expected faults, or rare faults.
——Db level (EPL Db): Equipment used in explosive dust environments, with a "high" protection level, and is not an ignition source under normal operation or expected fault conditions.
——Dc level (EPL Dc): Equipment used in explosive dust environments, with a "general" protection level, is not an ignition source during normal operation, and additional protective measures can be taken to ensure that effective ignition does not occur in situations where the ignition source is expected to frequently occur (such as lamp failure).
According to the current national standard GB 3836.1-2010 "Explosive Atmosphere Part 1: General Requirements for Equipment", under the same conditions, electrical equipment with explosion-proof markings meeting the Ex d IIC T6 Gb standard shall have a higher explosion-proof rating than electrical equipment with explosion-proof markings meeting the Ex d IIC T6 Gb standard.
For more information on explosion-proof certification, please contact Zhongnuo Testing directly
Service Hotline: 18924609560 (same WeChat account)
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