IEEE Std 2942-2023
IEEE Guide for In-Service Applicaton, Care, Maintenance, and Testng of Insulatng Flexible Sling for Live Working
- Standard No.
- IEEE Std 2942-2023
- Release Date
- 2023
- Published By
- Institute of Electrical and Electronics Engineers (IEEE) US / IEEE
- Latest
- IEEE Std 2942-2023
- Introduction
Standard Overview and Technical Background
IEEE Std 2942™-2023, "Guide for Field Application, Maintenance, and Testing of Insulated Flexible Slings for Live Working," was developed by the IEEE Power & Energy Society's Transmission and Distribution Committee and officially approved on November 8, 2023. This standard provides full lifecycle management specifications for insulating flexible slings (IFS) for live working on UHV AC and DC transmission lines.
With voltage levels increasing to 1000 kV AC and ±800 kV DC, traditional insulating tie rods have become significantly limited in UHV live working due to their increased length (up to 10 meters), increased weight (up to 40 kg), and insufficient bending and torsional resistance. As an innovative solution, insulating flexible slings combine the smooth surface and high strength of FRP tools with the lightweight, moisture-resistant, and easily transportable advantages of insulating ropes, making them a crucial tool for insulator string replacement and maintenance.
Core Technical Requirements of the Standard
Insulated flexible slings consist of an ultra-high-strength core, a weatherproof sheath, and embedded end fittings. The standard sets clear material performance requirements: the sheath material must have a breakdown voltage of no less than 10 MV/m, a water absorption rate of no more than 0.15%, and a dielectric loss of no more than 0.3%; end fittings must comply with ASTM or AISI standards; and the core must be constructed of synthetic fibers with high electromechanical performance and treated for moisture resistance.
Test type Design verification test Factory test In-service test Test cycle Electrical performance test Dry flashover, wet flashover, leakage current, etc. Power frequency withstand voltage, switching shock Power frequency withstand voltage, switching shock Annual test Mechanical performance test Elongation, breaking load, static and dynamic load Static and dynamic load Static and dynamic load Annual test Appearance Inspection Comprehensive Inspection Comprehensive Inspection Inspection Before Use Before Each Use
Electrical Performance Test Specifications
The standard specifies detailed electrical test methods, including dry-state power frequency flashover tests, artificial rain flashover tests, and high-humidity leakage current tests. Testing requirements strictly adhere to the IEEE Std 4™-2013 high-voltage test technical standard, and the measurement system error is controlled within 5%.
For 1000kV AC applications, the IFS must pass a 6.8-meter-long 1270kV power frequency withstand voltage test (5 minutes) and a 6.3-meter-long 1695kV switching impulse withstand test (15 times). For ±800kV DC applications, it must pass a 6.6-meter-long 985kV DC withstand voltage test and a 1685kV switching impulse test. The in-service test voltage is 90% of the design verification test voltage.
Mechanical Performance Testing Requirements
Mechanical testing is performed using a hydraulic tensile testing machine calibrated in accordance with the latest version of ASTM E4 or ISO 7500-1. Key mechanical performance indicators include: elongation of no more than 2% at 75% of the failure load; no permanent deformation at a static test of 2.5 times the rated load for 5 minutes; and no damage at a dynamic test of 1.5 times the rated load three times.
Elongation test method: Mark a 500mm reference length under rated mechanical load. Load at 300mm/min to 50% of the failure load, then at 250mm/min to 75% of the failure load. Measure the length change within 1 minute and calculate the percentage.
Field Application and Maintenance Specifications
The standard emphasizes that when using IFS in the field, it is necessary to avoid dragging or rubbing against sharp corners of the tower and to implement moisture and rain protection measures. The working load must not exceed 80% of the rated load, and the inclination must not exceed 5%. Connections must only be made through the metal components at both ends. Rotational, swinging, and shear forces are strictly prohibited.
Storage requirements require a relative humidity of no more than 60%, a temperature of 5-40°C, and a distance of at least 1 meter from heat sources. Annual waxing is required to restore or enhance hydrophobicity. Visual inspection must be conducted before each use. Any surface defects, discoloration, or abnormal end fittings should be immediately removed from service.
Implementation Recommendations and Best Practices
Based on the standard requirements, users are advised to establish a comprehensive IFS lifecycle management system:
- Purchase and Acceptance: Verify product certification information and conduct comprehensive factory testing and acceptance
- Usage Management: Establish a usage record for each IFS, recording the number of applications and operating conditions
- Maintenance: Develop an annual maintenance plan, including electrical testing, mechanical testing, and surface treatment
- Personnel Training: Train operators on correct usage and inspection techniques
- Scrap Disposal: Establish clear scrapping standards and promptly replace IFS that have reached the end of their service life or have degraded performance
During implementation, special attention should be paid to altitude correction: In areas above 1000 meters, the effective insulation length must be corrected according to IEEE Std 516™-2021 to ensure that the safety distance requirements are met.
Technological Evolution and Standard Significance
The release of IEEE 2942-2023 marks a new stage in the standardization of UHV live working tools. Compared with traditional insulated pull rods, IFS offers significant advantages in the UHV field: weight reduction of over 60%, 70% reduction in transportation and storage space, and significantly improved operational flexibility.
This standard not only provides detailed technical specifications but, more importantly, establishes a complete quality assurance system, forming a closed-loop management system from design verification and factory inspection to in-service testing, providing technical support for ensuring the safety of UHV live working. With the continuous development of flexible insulation material technology, IFS will play an important role in the future at higher voltage levels and under more complex working conditions.
IEEE Std 2942-2023 Referenced Document
- ASTM E4 Standard Practices for Force Verification of Testing Machines
- IEC 60060-1:2010 High-voltage test techniques - Part 1: General definitions and test requirements
- IEEE Std 4-2013 IEEE Standard for High-Voltage Testing Techniques - Redline
- IEEE Std 516-2021 IEEE Guide for Maintenance Methods on Energized Power Lines - Redline
- IEEE Std 978 IEEE Guide for In-Service Maintenance and Electrical Testing of Live-Line Tools
- ISO 7500-1 Metallic materials - Calibration and verification of static uniaxial testing machines - Part 1: Tension/compression testing machines - Calibration and verification of the force-measuring system
IEEE Std 2942-2023 history
- 2023 IEEE Std 2942-2023 IEEE Guide for In-Service Applicaton, Care, Maintenance, and Testng of Insulatng Flexible Sling for Live Working
