The industry standard for explosion-proof electric heaters is drafted according to the rules given in GB/T1.1-2009. The industry standard shall comply with national standards, industry standards, local standards, national industrial policies, and relevant national laws, regulations, and rules, and shall meet the relevant requirements aimed at protecting life and property safety. Otherwise, this standard is invalid and shall not be used as a basis for organizing production. This explosion-proof electric heater standard's technical requirements are lower than national or industry standards, or if no provisions are made in terms of safety technical requirements, national and industry standards shall prevail.
The following documents are indispensable for the application of this document. For dated references, only the edition cited applies.
B3836.1 Explosive atmospheres: Equipment general requirements.
GB3836.2 Explosive atmospheres: Equipment protected by flameproof enclosures "d".
GB4208 Degrees of protection provided by enclosures (IP code).
GB/T13384 General specifications for packaging of mechanical and electrical products.
JB/T2379 Metallic tubular heating elements.
Technical requirements for electric heater standards:
1. The electric heater shall comply with the requirements of this standard and be manufactured according to the drawings and technical documents approved by the National Quality Supervision and Inspection Center for Explosion-Proof Electrical Products. The materials used for each component of the electric heater shall comply with the provisions of relevant standards.
2. The electric heater shall work reliably under the following environmental conditions:
1) Ambient temperature: -20°C to +40°C
2) Altitude not exceeding 1000m
3) Relative humidity of surrounding air not greater than 90% (at ambient temperature of +25°C)
4) Places with explosive mixtures of flammable gases, vapors, and air of groups IIA, IIIB, and temperature classes T1~T4 in Zone 1 or Zone 2.
5) In environments without gases or vapors that damage insulation.
6) In places without significant shaking or impact vibration.
3. The explosion-proof electric heater industry follows the GB3836 standard:
1) It is made as a flameproof type according to GB3836.2, with explosion-proof marking ExdⅡBT4Gb.
2) The parameters of flameproof joints shall comply with relevant provisions of GB3836.2.
3) Internal and external grounding bolts shall be provided, and the grounding bolts shall comply with GB3836.1. A grounding symbol shall be near the grounding bolts.
4) All fasteners shall be made of stainless steel or steel treated with anti-rust measures such as electroplating.
5). The electric heater wiring chamber inner surface shall be evenly coated with ℃32~℃39 arc-resistant paint (the flameproof joint surface shall be coated with anti-rust oil). The flameproof joint surface must be precision machined on a lathe to ensure smoothness and flatness.
