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.
Porcelain bushing type outdoor power cable termination is a traditional type of termination used for high-voltage power cables, typically in substations or overhead line connections. It provides electrical insulation, mechanical support, and environmental protection for the cable end.
✔ Excellent long-term reliability in harsh environments.
✔ High mechanical and electrical durability.
✔ Low maintenance compared to polymer bushings (in some cases).
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. Outlet clamp 2. Grading shield 3. Core insulation 4. Polyisobutylene 5. Porcelain bushing 6. Stress cone 7. Fixed plate 8. Support insulator 9. Tail pipe 10. Cable
Size mm | 48/66kV | 64/110kV | 80/138kV | 127/220kV |
H | 1270 | 1500 | 1750 | 2500 |
A | 1510 | 1935 | 2085 | 3100 |
B | 1925 | 2155 | 2400 | 3600 |
C | 450 | 450 | 450 | 650 |
D | 200 | 200 | 200 | 300 |
E | Φ22 | Φ22 | Φ22 | Φ32 |
Creepage distance | ≥2248 | ≥3906 | ≥4495 | ≥7812 |
| Parameter | Description |
|---|---|
| Rated Voltage (Ur) | System voltage (e.g., 11 kV, 33 kV, 132 kV) |
| Lightning Impulse Withstand Voltage (BIL) | Peak voltage the bushing can withstand (e.g., 95 kV for 11 kV systems, 550 kV for 132 kV) |
| Power Frequency Withstand Voltage (1 min AC) | Short-duration AC withstand test voltage (e.g., 28 kV for 11 kV, 230 kV for 132 kV) |
| Partial Discharge Level | Maximum allowable PD (typically <10 pC for HV bushings) |
| Creepage Distance | Minimum surface distance to prevent flashover (depends on pollution level) |
| Dielectric Loss (Tan δ) | Measure of insulation quality (should be low, e.g., <0.5%) |
Our company produces two main of porcelain bushing outdoor termination, 4E-YJZWC3 and 4E-YJZWC4, which are widely used for outdoor high-voltage overhead lines and cable connections with anti-pollution grade of grade III, and grade IV. They are composed of connecting bar, stress cone, porcelain bushing, and tail tube. We use imported liquid silicone rubber injection molding to make stress cone, which has long-term stability of lasting hold power and electric field uniformity ability. Porcelain bushing is using high strength inorganic electric porcelain with stable performance. Porcelain bushing is applying skirt structure, and the overall is conical with good performance of pollution flashover resistance, weather resistance, anti-leakage marks, anti-erosion and water repellent ability. The porcelain is filled with insulating oil with excellent electrical insulation properties, and the mutual dissolution or penetration is as low as 1/1000 between silicon stress cone to ensure the long-term safe operation of the product. Our product is using multiple sealing structure which can effectively prevent the leakage of water immersion and insulating oil. All of the seals are using imported NBR or silicon rubber material. All of the fastener raw-material are stainless steel with good waterproof seal performance.
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 | ✔ | ✔ | ✔ | ✔ | ✔ | ||
Porcelain Insulator
Made of high-grade ceramic (porcelain) for excellent dielectric strength and weather resistance.
Resistant to UV rays, moisture, and pollution.
Smooth, glazed surface prevents tracking and flashover.
Design & Construction
Hollow core design allows the cable conductor to pass through.
Flanged base for mounting on transformers, switchgear, or overhead poles.
Sealing system (e.g., gaskets or O-rings) to prevent moisture ingress.
Voltage Rating
Commonly used for medium voltage (MV, 1kV–36kV) and high voltage (HV, up to 245kV or higher) applications.
Mechanical Strength
High compressive strength to withstand conductor load and wind forces.
Resistant to thermal cycling (expansion/contraction due to temperature changes).
Termination Method
The cable conductor is terminated inside the bushing, often with a stress cone or geometric stress control to manage electric field distribution.
May include oil or gas filling (in older designs) or dry-type (resin or rubber) insulation.
Transformer bushings (connecting cables to transformers).
Switchgear terminations (outdoor installations).
Overhead line connections (transition from underground cable to overhead line).
Substation cable terminations.
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.
Porcelain bushing type outdoor power cable termination is a traditional type of termination used for high-voltage power cables, typically in substations or overhead line connections. It provides electrical insulation, mechanical support, and environmental protection for the cable end.
✔ Excellent long-term reliability in harsh environments.
✔ High mechanical and electrical durability.
✔ Low maintenance compared to polymer bushings (in some cases).
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. Outlet clamp 2. Grading shield 3. Core insulation 4. Polyisobutylene 5. Porcelain bushing 6. Stress cone 7. Fixed plate 8. Support insulator 9. Tail pipe 10. Cable
Size mm | 48/66kV | 64/110kV | 80/138kV | 127/220kV |
H | 1270 | 1500 | 1750 | 2500 |
A | 1510 | 1935 | 2085 | 3100 |
B | 1925 | 2155 | 2400 | 3600 |
C | 450 | 450 | 450 | 650 |
D | 200 | 200 | 200 | 300 |
E | Φ22 | Φ22 | Φ22 | Φ32 |
Creepage distance | ≥2248 | ≥3906 | ≥4495 | ≥7812 |
| Parameter | Description |
|---|---|
| Rated Voltage (Ur) | System voltage (e.g., 11 kV, 33 kV, 132 kV) |
| Lightning Impulse Withstand Voltage (BIL) | Peak voltage the bushing can withstand (e.g., 95 kV for 11 kV systems, 550 kV for 132 kV) |
| Power Frequency Withstand Voltage (1 min AC) | Short-duration AC withstand test voltage (e.g., 28 kV for 11 kV, 230 kV for 132 kV) |
| Partial Discharge Level | Maximum allowable PD (typically <10 pC for HV bushings) |
| Creepage Distance | Minimum surface distance to prevent flashover (depends on pollution level) |
| Dielectric Loss (Tan δ) | Measure of insulation quality (should be low, e.g., <0.5%) |
Our company produces two main of porcelain bushing outdoor termination, 4E-YJZWC3 and 4E-YJZWC4, which are widely used for outdoor high-voltage overhead lines and cable connections with anti-pollution grade of grade III, and grade IV. They are composed of connecting bar, stress cone, porcelain bushing, and tail tube. We use imported liquid silicone rubber injection molding to make stress cone, which has long-term stability of lasting hold power and electric field uniformity ability. Porcelain bushing is using high strength inorganic electric porcelain with stable performance. Porcelain bushing is applying skirt structure, and the overall is conical with good performance of pollution flashover resistance, weather resistance, anti-leakage marks, anti-erosion and water repellent ability. The porcelain is filled with insulating oil with excellent electrical insulation properties, and the mutual dissolution or penetration is as low as 1/1000 between silicon stress cone to ensure the long-term safe operation of the product. Our product is using multiple sealing structure which can effectively prevent the leakage of water immersion and insulating oil. All of the seals are using imported NBR or silicon rubber material. All of the fastener raw-material are stainless steel with good waterproof seal performance.
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 | ✔ | ✔ | ✔ | ✔ | ✔ | ||
Porcelain Insulator
Made of high-grade ceramic (porcelain) for excellent dielectric strength and weather resistance.
Resistant to UV rays, moisture, and pollution.
Smooth, glazed surface prevents tracking and flashover.
Design & Construction
Hollow core design allows the cable conductor to pass through.
Flanged base for mounting on transformers, switchgear, or overhead poles.
Sealing system (e.g., gaskets or O-rings) to prevent moisture ingress.
Voltage Rating
Commonly used for medium voltage (MV, 1kV–36kV) and high voltage (HV, up to 245kV or higher) applications.
Mechanical Strength
High compressive strength to withstand conductor load and wind forces.
Resistant to thermal cycling (expansion/contraction due to temperature changes).
Termination Method
The cable conductor is terminated inside the bushing, often with a stress cone or geometric stress control to manage electric field distribution.
May include oil or gas filling (in older designs) or dry-type (resin or rubber) insulation.
Transformer bushings (connecting cables to transformers).
Switchgear terminations (outdoor installations).
Overhead line connections (transition from underground cable to overhead line).
Substation cable terminations.
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.
