Shenhai Explosion-Proof
Explosion-proof electrical equipment is categorized into two types based on the natural environment of their actual application: one for mining use and the other for factory use. Depending on the characteristics of the equipment in generating sparks, electric arcs, and hazardous temperatures, and to prevent the ignition of flammable compounds, they are divided into the following eight types:
1. Flameproof Type (marked ‘d’):
This is a type of electrical equipment with an explosion-proof enclosure capable of withstanding the explosive pressure of internal combustible gas compounds and preventing the spread of explosions to surrounding flammable compounds. Suitable for all locations with explosion risk.
2. Increased Safety Type (marked ‘e’):
Under normal operational conditions, this type of equipment is unlikely to create electric arcs or sparks and will not reach temperatures capable of igniting flammable compounds. Its design incorporates multiple safety measures to enhance the level of security and prevent the creation of arcs, sparks, and high temperatures under normal and recognized load conditions.
3. Intrinsically Safe Type (marked ‘ia’, ‘ib’):
Using IEC76-3 flame test equipment, this type ensures that sparks and thermal effects produced under normal operation or specified common faults cannot ignite specified flammable compounds. These devices are categorized into ‘ia’ and ‘ib’ levels based on application areas and safety levels. ‘ia’ level devices will not ignite flammable gases under normal operation, one common fault, or two common faults. ‘ib’ level devices will not ignite flammable gases under normal operation and one common fault.
4. Pressurized Type (marked ‘p’):
This type has a pressurized enclosure that maintains a higher internal pressure of protective gas, like air or inert gas, than the external flammable environment, preventing external compounds from entering the enclosure.
5. Oil-Filled Type (marked ‘U’):
Electrical equipment or parts thereof are immersed in oil to prevent ignition of flammable compounds above the oil level or outside the enclosure. High-voltage oil circuit breakers are an example.
6. Sand-Filled Type (marked ‘q’):
The enclosure is filled with sand to ensure that any electric arcs, dispersed sparks, or excessive temperatures on the enclosure wall or sand surface under certain operating conditions cannot ignite surrounding flammable compounds.
7. Non-Sparking Type (marked ‘n’):
Under normal operating conditions, this type will not ignite surrounding explosive compounds and typically does not produce common faults with ignition capabilities.
8. Special Type (marked ‘s’):
These are electrical devices with unique explosion-proof measures not falling into any of the aforementioned categories. For example, devices filled with stone sand belong to this category.