GB7958-2014
Capacitor discharge type exploders for coal mines
煤矿用电容式发爆器
GB 7958-2014 is a current mandatory Chinese national standard for Capacitor discharge type exploders for coal mines. It appears in the Electronics compliance cluster with a product safety focus and has an implementation date of Nov 1, 2015.
Applicability depends on product scope, certification route, competent authority notices and transition rules. Requst for the translation or verify source before using this record in a compliance decision.
Compliance overview
Scope and applicability
This standard applies specifically to capacitor discharge type exploders used in coal mines. It is designed for equipment operating in underground environments where explosive mixtures of methane and coal dust are present. It does not apply to non-capacitor-based blasting machines or equipment used in surface mining operations. The standard covers terminology, technical requirements, and testing methods for these specialized mining devices.
Technical requirements
This standard specifies stringent mandatory technical requirements for capacitor discharge exploders. Manufacturers must ensure complete compliance with both intrinsic safety and flameproof performance criteria. The standard details requirements for operational switches, mandating that both mechanical and electronic switches prevent accidental power supply or interruption during the charging and blasting sequence. The standard sets specific parameters for charging time and maximum allowable load resistance based on the rated number of detonators. It also defines the safe power supply time, requiring that the output voltage drops below intrinsic safety limits within a strict timeframe to prevent sparks from broken or reconnected blasting circuits. Furthermore, the standard outlines critical explosion-proof performance requirements, referencing the GB 3836 series for structural parameters, clearances, and creepage distances. Devices must pass rigorous dielectric strength tests and maintain specific surface temperature limits under normal and fault conditions. Environmental durability requirements, including resistance to damp heat, extreme storage temperatures, vibration, and free fall, are also mandated to ensure reliability in harsh mining environments.
Testing methods
The standard outlines a comprehensive suite of testing methods to verify compliance. Key tests include the measurement of charging time, safe power supply time, and ignition expenditure using specialized parameter testers. Explosion-proof performance is verified through spark ignition tests, dielectric strength tests, and static pressure (water pressure) tests on the enclosure. Additionally, environmental tests such as damp heat, high/low temperature storage, vibration, and free fall drop tests are conducted to ensure mechanical and operational integrity under demanding mining conditions.
FAQs
What products are regulated under GB 7958-2014?
This standard applies to capacitor discharge type exploders specifically designed for use in underground coal mines where explosive mixtures of methane and coal dust are present.
Are there any updates from the previous version of GB 7958-2014?
The 2014 version has enhanced and refined the explosion-proof requirements, updated the ignition expenditure and maximum allowable load resistance parameters according to GB 8031-2005, and revised the service life testing procedures and frequencies.
How does GB 7958-2014 differ from international standards?
GB 7958-2014 incorporates the explosion protection principles of the GB 3836 series (which are largely aligned with IEC 60079), but it includes specific, mandatory adaptations for coal mine capacitor exploders, such as retaining a flameproof enclosure design for exposed high-voltage terminals that would otherwise be classified as "special type."
The summary above provides a high-level overview of GB 7958-2014. To ensure complete compliance for your products entering the Chinese market, a precise and professional translation of the full technical specifications is essential. Purchase our high-quality English translation of GB 7958-2014 today to access all detailed parameters, tables, and testing procedures.
Applicability hints
- Type
- Product
- CCS
- K35
- ICS
- 29.260.20
- Competent department
- National Mine Safety Administration
- Technical committee
- National Mine Safety Administration
Relationships
Replaces:GB 7958-2000