GB20294-2006
Safety requirements of flameproof crane & metallurgical and canned motors
隔爆型起重冶金和屏蔽电机安全要求
GB 20294-2006 is a current mandatory Chinese national standard for Safety requirements of flameproof crane & metallurgical and canned motors. It appears in the Electronics compliance cluster with a product safety focus and has an implementation date of Jan 1, 2007.
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 specifies the safety requirements for flameproof crane motors, flameproof conical rotor motors, and flameproof canned motors. It applies to flameproof motors used for power transmission in various lifting machinery and similar equipment, as well as flameproof canned motors used in the petroleum and chemical industries for transporting fluids without solid particles. This standard is mandatory for all applicable motor manufacturers. It references standards such as GB 755-2000 and GB 3836.2-2000.
Technical requirements
The standard outlines comprehensive safety requirements across several categories. It mandates that motors must meet the explosion-proof performance of GB 3836.2-2000 and be manufactured as flameproof type 'd'. Motors are classified into categories IIA, IIB, and IIC and temperature groups T1 to T4 based on maximum surface temperature limits. Structural requirements detail the specifications for flameproof joints, including surface roughness, maximum gaps, and minimum widths for different motor categories and volumes. It also specifies requirements for shafts, bearings, and the mechanical strength of the enclosure to withstand internal explosions without permanent deformation. Manufacturers must ensure enclosures can effectively contain internal explosions. Furthermore, the standard sets strict limits for clearance and creepage distances, the design of terminal boxes, and protective grounding devices. It also covers the structural integrity of canned motors, emphasizing that components in contact with pumped liquids must have sufficient mechanical strength and sealing performance to prevent any leakage.
Testing methods
The standard requires a series of rigorous tests to verify compliance. Key testing methods include thermal tests to determine temperature rises and maximum surface temperatures, and dielectric strength tests (power frequency and impulse) to ensure insulation integrity. Mechanical tests are critical, including over-speed tests, short-time over-torque tests, and enclosure pressure tests to prove the enclosure can withstand internal explosions. Internal ignition non-transmission tests are mandatory to verify flameproof performance. Additionally, the standard outlines procedures for moisture resistance tests, insulation structure evaluation, and rust prevention tests.
FAQs
What products are regulated under GB 20294-2006?
GB 20294-2006 regulates flameproof crane motors, flameproof conical rotor motors, and flameproof canned motors used in lifting machinery, petroleum, and chemical industries.
What are the temperature groups specified in this standard?
The standard classifies motors into temperature groups T1 to T4, which correspond to maximum surface temperature limits ranging from 450°C down to 135°C to prevent ignition of surrounding explosive gas environments.
Are there specific structural requirements for canned motors?
Yes, for canned motors, the standard requires that circulating pipes, joints, and stator/rotor shielding sleeves must not have fractures or un-welded areas. Components in contact with pumped liquids must ensure zero leakage, even if the stator shielding sleeve is damaged.
The summary above provides a high-level overview of GB 20294-2006. 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 20294-2006 today to access all detailed parameters, tables, and testing procedures.
Applicability hints
- Type
- Safety
- CCS
- K26
- ICS
- 29.160.30
- Competent department
- Ministry of Industry and Information Technology
- Technical committee
- Ministry of Industry and Information Technology
Relationships
Replaced by:GB 47501-2026 (Upcoming)