Cable Accessories are products that connect cables with transmission and distribution lines, as well as related distribution equipment. They generally refer to the intermediate and terminal connections of various cables in cable lines, and together with cables, they form the power transmission network; Cable accessories are mainly based on the characteristics of cable structure, which can not only restore the performance of cables, but also ensure the extension of cable length and the connection of terminals. The reliability of high-voltage cable accessories can be evaluated from the aspects of electrical performance, sealing and moisture-proof performance, mechanical performance, and process performance.
Fully fabricated type insulating power cable joint is a pre-assembled, ready-to-install joint designed to connect two or more power cables while maintaining electrical insulation, mechanical strength, and environmental protection. These joints are commonly used in medium-voltage (MV) and high-voltage (HV) power distribution systems.
✔ Quick and easy installation
✔ Consistent performance (factory-tested)
✔ Long service life with minimal maintenance
✔ Enhanced safety (reduced risk of insulation failure)
IEC 60137 – Insulated bushings for alternating voltages above 1000V
Covers general requirements, testing, and dimensions for high-voltage bushings, including porcelain types.
IEC 62217 – Polymeric HV insulators for indoor and outdoor use (for comparison with porcelain)
IEC 61462 – Composite hollow insulators for HV equipment
IEC 60815 – Selection and dimensioning of high-voltage insulators for polluted conditions
IEEE Std 48 – Standard for Test Procedures and Requirements for HV Alternating-Current Cable Terminations
Covers porcelain and polymer terminations for cables (1 kV to 765 kV).
IEEE Std 386 – Standard for Separable Insulated Connector Systems for Power Distribution Systems
IEEE Std 4 – Standard for High-Voltage Testing Techniques
BS EN 50180/50181 – Bushings above 1 kV AC and 1.5 kV DC
BS EN 50393 – Test methods for outdoor terminations for HV cables
1. Glass fiber reinforced plastics shell 2. Copper shell 3. Stress cone 4. Cable insulation 5. Epoxy insulating parts 6. Connecting tube 7. Screen tile 8. Prefabricated main body 9. Coaxial cable 10. Cable
Size mm | 48/66kV | 64/110kV | 80/138kV | 127/220kV |
L | 1600 | 1600 | 1632 | 1760 |
A | 2000 | 2100 | 2200 | 2400 |
| Parameter | Description |
|---|---|
| Rated Voltage (U₀/U/Um) | - U₀: Rated power frequency voltage between conductor and earth (kV) - U: Rated system voltage (kV) - Um: Maximum system voltage (kV) |
| Lightning Impulse Withstand Voltage (LIWV) | Peak voltage the joint can withstand during lightning strikes (e.g., 95 kV, 170 kV, 250 kV) |
| Power Frequency Withstand Voltage | AC voltage withstand capability (e.g., 22 kV for 5 mins) |
| Partial Discharge Level | Should be minimal (e.g., <10 pC at 1.5U₀) |
| Current Rating (A) | Continuous current-carrying capacity (depends on conductor size & material) |
| Short-Circuit Current (kA, 1s or 3s) | Maximum fault current the joint can handle without damage |
Our company produces two main 4E-YJJTI,YJJJI fully prefabricated silicone rubber insulated straight through/insulating joint, 4E-YJJTI and 4E-YJJJI, applied to connection between the two identical section or similar section of the cable. They are composed of prefabricated insulating body (stress cone included), metal protective shell, and fiberglass outer protective shell. The main body of prefabricated soft silicone rubber is using imported liquid silicone rubber injection rubber molding soft dry structure, which has long-term stability of lasting hold power and electric field uniform ability. Metal protective shell ring is composed with two different lengths of metal tail tube and insulating tuber, filled with insulating sealant inside, and covered with sealing insulation.
For different work environment and users’ specified requirement, metal protective shell and fiberglass outlet shell are optional. Without water damage, mechanical damage, or corrosion, outer metal protective shell and fiberglass free are better for heart dissipation of the product to ensure a long life.
Item | Test requirement | Test type | Products type | ||||||
48/66 | 64/110 | 127/220 | Porcelain bushing | Composite busing | GIS termination | Straight through/ Insulating joint | Soft dry type termination | ||
Sealing fittings, porcelain bushing, composite bushing | 0.25±0.01MPa/1h, no leakage | R | ✔ | ✔ | ✔ | — | — | ||
Epoxy bushing | 0.6~0.7MPa/1h, no leakage | ||||||||
Prefabricated body partial discharge test | 72kV | 96kV | 190kV | R | ✔ | ✔ | ✔ | ✔ | ✔ |
Partial discharge in the background | |||||||||
Prefabricated body power frequency withstand voltage test | 120kV | 160kV | 318kV | R | ✔ | ✔ | ✔ | ✔ | ✔ |
30min, no flashover no breakdown | |||||||||
Partial discharge test at ambient temperature | 72kV | 96kV | 190kV | T | ✔ | ✔ | ✔ | ✔ | ✔ |
Partial discharge in the background | |||||||||
Thermal cycling voltage test | 96kV | 128kV | 254kV | T | ✔ | ✔ | ✔ | ✔ | ✔ |
20 cycles, no flashover no breakdown | |||||||||
Partial discharge at high temperature | 72kV | 96kV | 190kV | T | ✔ | ✔ | ✔ | ✔ | ✔ |
Partial discharge in the background | |||||||||
Lighting impulse voltage test and the subsequent power frequency withstand voltage test | 450kV | 550kV | 1050kV | T | ✔ | ✔ | ✔ | ✔ | ✔ |
10 times, no flashover no breakdown | |||||||||
120kV | 160kV | 318kV | |||||||
15min, no flashover no breakdown | |||||||||
Immersion voltage test on outer protective sheath of direct-buried joint | 60/75kV impact both ends, 30/37.5kV impact one end to the ground | 60/95kVimpact both ends, 30/47.5kV impact one end to the ground | T | — | — | — | ✔ | — | |
Sealing test after installing accessories | 0.25±0.01MPa/1h, no leakage | T | ✔ | ✔ | ✔ | ✔ | ✔ | ||
Outdoor termination frequency voltage test in rain | 140kV | 185kV | 460kV | T | ✔ | ✔ | — | — | ✔ |
1min, no flashover no breakdown | |||||||||
Post insulator voltage test | 20kV/1min, no flashover no breakdown | T | ✔ | ✔ | — | — | — | ||
Outdoor termination radio interference test | 61kV | 81kV | 140kV | A | ✔ | ✔ | — | — | ✔ |
1MHz radio interference, voltage≤450μV | 1MHz radio interference, voltage≤500μV | ||||||||
Accessories sample test | Detect accessories system, no significant errors effect operating | T | ✔ | ✔ | ✔ | ✔ | ✔ | ||
DC voltage test | / | 20kV/1min between inner conductor and metallic screen of joint, no breakdown | T | — | — | — | ✔ | — | |
Conductor connecting pole (tube) pressure welding fitting performance test | After crimping, the total resistance is not 1.2 times more than the same length and cross sectional area of conductor | T | ✔ | ✔ | ✔ | ✔ | ✔ | ||
Pre-assembled Design
Comes as a complete kit with all necessary components (insulation, shielding, sealing, and mechanical protection).
Reduces installation time and minimizes human error.
Insulation System
Uses high-quality insulating materials such as EPR (Ethylene Propylene Rubber), silicone rubber, or heat-shrink materials to prevent electrical leakage.
May include stress control layers to manage electric field distribution.
Sealing & Environmental Protection
Waterproof and moisture-resistant design (often using heat-shrink tubes, cold-shrink technology, or resin-based sealing).
Resistant to chemicals, UV radiation, and extreme temperatures.
Mechanical Strength
Reinforced with armoring, clamps, or robust outer sleeves to withstand mechanical stress and vibrations.
Suitable for direct burial, underground, or overhead installations.
Electrical Performance
Maintains continuous conductivity with low contact resistance.
Provides electrical stress relief to prevent partial discharges.
Underground power cable networks
Substation connections
Industrial power distribution
Renewable energy systems (wind/solar farms)
Railway and metro power systems
Use wooden boxes and plastic packaging to protect the bushing from physical damage, moisture, and environmental pollutants.
Delivered worldwide via sea, air, or land freight. Custom shipping solutions are available based on customer requirements.
Cable Accessories are products that connect cables with transmission and distribution lines, as well as related distribution equipment. They generally refer to the intermediate and terminal connections of various cables in cable lines, and together with cables, they form the power transmission network; Cable accessories are mainly based on the characteristics of cable structure, which can not only restore the performance of cables, but also ensure the extension of cable length and the connection of terminals. The reliability of high-voltage cable accessories can be evaluated from the aspects of electrical performance, sealing and moisture-proof performance, mechanical performance, and process performance.
Fully fabricated type insulating power cable joint is a pre-assembled, ready-to-install joint designed to connect two or more power cables while maintaining electrical insulation, mechanical strength, and environmental protection. These joints are commonly used in medium-voltage (MV) and high-voltage (HV) power distribution systems.
✔ Quick and easy installation
✔ Consistent performance (factory-tested)
✔ Long service life with minimal maintenance
✔ Enhanced safety (reduced risk of insulation failure)
IEC 60137 – Insulated bushings for alternating voltages above 1000V
Covers general requirements, testing, and dimensions for high-voltage bushings, including porcelain types.
IEC 62217 – Polymeric HV insulators for indoor and outdoor use (for comparison with porcelain)
IEC 61462 – Composite hollow insulators for HV equipment
IEC 60815 – Selection and dimensioning of high-voltage insulators for polluted conditions
IEEE Std 48 – Standard for Test Procedures and Requirements for HV Alternating-Current Cable Terminations
Covers porcelain and polymer terminations for cables (1 kV to 765 kV).
IEEE Std 386 – Standard for Separable Insulated Connector Systems for Power Distribution Systems
IEEE Std 4 – Standard for High-Voltage Testing Techniques
BS EN 50180/50181 – Bushings above 1 kV AC and 1.5 kV DC
BS EN 50393 – Test methods for outdoor terminations for HV cables
1. Glass fiber reinforced plastics shell 2. Copper shell 3. Stress cone 4. Cable insulation 5. Epoxy insulating parts 6. Connecting tube 7. Screen tile 8. Prefabricated main body 9. Coaxial cable 10. Cable
Size mm | 48/66kV | 64/110kV | 80/138kV | 127/220kV |
L | 1600 | 1600 | 1632 | 1760 |
A | 2000 | 2100 | 2200 | 2400 |
| Parameter | Description |
|---|---|
| Rated Voltage (U₀/U/Um) | - U₀: Rated power frequency voltage between conductor and earth (kV) - U: Rated system voltage (kV) - Um: Maximum system voltage (kV) |
| Lightning Impulse Withstand Voltage (LIWV) | Peak voltage the joint can withstand during lightning strikes (e.g., 95 kV, 170 kV, 250 kV) |
| Power Frequency Withstand Voltage | AC voltage withstand capability (e.g., 22 kV for 5 mins) |
| Partial Discharge Level | Should be minimal (e.g., <10 pC at 1.5U₀) |
| Current Rating (A) | Continuous current-carrying capacity (depends on conductor size & material) |
| Short-Circuit Current (kA, 1s or 3s) | Maximum fault current the joint can handle without damage |
Our company produces two main 4E-YJJTI,YJJJI fully prefabricated silicone rubber insulated straight through/insulating joint, 4E-YJJTI and 4E-YJJJI, applied to connection between the two identical section or similar section of the cable. They are composed of prefabricated insulating body (stress cone included), metal protective shell, and fiberglass outer protective shell. The main body of prefabricated soft silicone rubber is using imported liquid silicone rubber injection rubber molding soft dry structure, which has long-term stability of lasting hold power and electric field uniform ability. Metal protective shell ring is composed with two different lengths of metal tail tube and insulating tuber, filled with insulating sealant inside, and covered with sealing insulation.
For different work environment and users’ specified requirement, metal protective shell and fiberglass outlet shell are optional. Without water damage, mechanical damage, or corrosion, outer metal protective shell and fiberglass free are better for heart dissipation of the product to ensure a long life.
Item | Test requirement | Test type | Products type | ||||||
48/66 | 64/110 | 127/220 | Porcelain bushing | Composite busing | GIS termination | Straight through/ Insulating joint | Soft dry type termination | ||
Sealing fittings, porcelain bushing, composite bushing | 0.25±0.01MPa/1h, no leakage | R | ✔ | ✔ | ✔ | — | — | ||
Epoxy bushing | 0.6~0.7MPa/1h, no leakage | ||||||||
Prefabricated body partial discharge test | 72kV | 96kV | 190kV | R | ✔ | ✔ | ✔ | ✔ | ✔ |
Partial discharge in the background | |||||||||
Prefabricated body power frequency withstand voltage test | 120kV | 160kV | 318kV | R | ✔ | ✔ | ✔ | ✔ | ✔ |
30min, no flashover no breakdown | |||||||||
Partial discharge test at ambient temperature | 72kV | 96kV | 190kV | T | ✔ | ✔ | ✔ | ✔ | ✔ |
Partial discharge in the background | |||||||||
Thermal cycling voltage test | 96kV | 128kV | 254kV | T | ✔ | ✔ | ✔ | ✔ | ✔ |
20 cycles, no flashover no breakdown | |||||||||
Partial discharge at high temperature | 72kV | 96kV | 190kV | T | ✔ | ✔ | ✔ | ✔ | ✔ |
Partial discharge in the background | |||||||||
Lighting impulse voltage test and the subsequent power frequency withstand voltage test | 450kV | 550kV | 1050kV | T | ✔ | ✔ | ✔ | ✔ | ✔ |
10 times, no flashover no breakdown | |||||||||
120kV | 160kV | 318kV | |||||||
15min, no flashover no breakdown | |||||||||
Immersion voltage test on outer protective sheath of direct-buried joint | 60/75kV impact both ends, 30/37.5kV impact one end to the ground | 60/95kVimpact both ends, 30/47.5kV impact one end to the ground | T | — | — | — | ✔ | — | |
Sealing test after installing accessories | 0.25±0.01MPa/1h, no leakage | T | ✔ | ✔ | ✔ | ✔ | ✔ | ||
Outdoor termination frequency voltage test in rain | 140kV | 185kV | 460kV | T | ✔ | ✔ | — | — | ✔ |
1min, no flashover no breakdown | |||||||||
Post insulator voltage test | 20kV/1min, no flashover no breakdown | T | ✔ | ✔ | — | — | — | ||
Outdoor termination radio interference test | 61kV | 81kV | 140kV | A | ✔ | ✔ | — | — | ✔ |
1MHz radio interference, voltage≤450μV | 1MHz radio interference, voltage≤500μV | ||||||||
Accessories sample test | Detect accessories system, no significant errors effect operating | T | ✔ | ✔ | ✔ | ✔ | ✔ | ||
DC voltage test | / | 20kV/1min between inner conductor and metallic screen of joint, no breakdown | T | — | — | — | ✔ | — | |
Conductor connecting pole (tube) pressure welding fitting performance test | After crimping, the total resistance is not 1.2 times more than the same length and cross sectional area of conductor | T | ✔ | ✔ | ✔ | ✔ | ✔ | ||
Pre-assembled Design
Comes as a complete kit with all necessary components (insulation, shielding, sealing, and mechanical protection).
Reduces installation time and minimizes human error.
Insulation System
Uses high-quality insulating materials such as EPR (Ethylene Propylene Rubber), silicone rubber, or heat-shrink materials to prevent electrical leakage.
May include stress control layers to manage electric field distribution.
Sealing & Environmental Protection
Waterproof and moisture-resistant design (often using heat-shrink tubes, cold-shrink technology, or resin-based sealing).
Resistant to chemicals, UV radiation, and extreme temperatures.
Mechanical Strength
Reinforced with armoring, clamps, or robust outer sleeves to withstand mechanical stress and vibrations.
Suitable for direct burial, underground, or overhead installations.
Electrical Performance
Maintains continuous conductivity with low contact resistance.
Provides electrical stress relief to prevent partial discharges.
Underground power cable networks
Substation connections
Industrial power distribution
Renewable energy systems (wind/solar farms)
Railway and metro power systems
Use wooden boxes and plastic packaging to protect the bushing from physical damage, moisture, and environmental pollutants.
Delivered worldwide via sea, air, or land freight. Custom shipping solutions are available based on customer requirements.
