I. Product Overview
The JY TTL-15kV/24kV 600A Deadbreak T Connector is a non-load-breaking cable accessory designed specifically for 15kV/24kV (10kV/20kV level) medium-voltage power distribution systems. It features a fully insulated, fully sealed, touch-sensitive tapered structure and serves as a matching connection component for T-type cable joints. This allows for the connection between cables and T-type joints, and between T-type joints and equipment bushings. It combines conductive connection, insulation protection, and sealing protection functions, and is widely used in American-style ring main units, prefabricated substations, cable branch boxes, and other equipment. It is a key transition component for constructing separable interfaces in medium-voltage power distribution systems.
II. Product Characteristics
1. Electrical and insulation properties
- Made of high-purity EPDM ethylene propylene diene monomer rubber through integral injection molding, it has no seams or air gaps, excellent insulation performance, can withstand the rated voltage of 15kV/24kV system and short-time overvoltage, meets the operating requirements of the maximum working voltage of 17.5kV/24kV, and has sufficient insulation margin.
- With a built-in optimized electric field structure, the electric field is evenly distributed, effectively suppressing partial discharge. There is no risk of electrical erosion or breakdown during long-term operation, and the partial discharge amount is ≤10pC (below 1.5U₀).
- With built-in copper conductive components, it has excellent conductivity, low contact resistance, can carry a rated current of 600A, generates little heat during long-term operation, and has strong corrosion and oxidation resistance, making it suitable for high-current power distribution scenarios.
- With a conical sealing structure at both ends and an IP67 protection rating, it can achieve sealed isolation between the equipment and accessories, preventing moisture and dust from entering and improving the system’s moisture-proof and waterproof performance.
2. Structural and Safety Features
- With a fully insulated, touchable structure and high outer insulation strength, the outer casing can be directly touched during operation without the risk of electric shock, ensuring the safety of maintenance personnel.
- The tapered integrated design is compatible with 15kV/24kV 600A standard interfaces at both ends, enabling the conversion between T-type connectors and equipment bushings/cable accessories. Installation is convenient and requires no additional tools.
- Designed to prevent misconnection and loosening, the interface size strictly matches American standard accessories, and can only be matched with accessories of the corresponding specifications, eliminating the risk of misconnection, loosening and falling off.
- With its compact structure and tapered design, it facilitates installation and positioning, and is compatible with the installation space of T-type connectors and equipment sleeves without taking up additional equipment space.
3. Environmental and Weather Resistance
- It has excellent weather resistance and can adapt to a wide temperature range of -40℃ to +90℃. The elasticity and insulation properties of the rubber do not decrease under high and low temperatures, and there is no risk of cracking or embrittlement. It is suitable for various outdoor and indoor scenarios.
- It is moisture-proof, waterproof, stain-proof, and salt spray-proof, and can operate stably for a long time in harsh environments such as underground, damp, and dusty conditions, and is not afraid of rain or condensation.
- It is resistant to aging, ultraviolet rays, and ozone corrosion, with a service life of over 30 years. It requires no maintenance and reduces subsequent operation and maintenance costs.
4. Mechanical and Adaptation Characteristics
- It has high mechanical strength, is impact and vibration resistant, and can withstand mechanical stress during transportation, installation and operation without deformation or damage risk. Its seismic resistance level reaches level 8.
- It is compatible with 15kV/24kV 600A standard cable accessory interfaces and can be interchanged with T-type cable joints, bushings, and elbow joints of the same specifications, with strong compatibility.
- The interface is standardized and conforms to IEEE 386 and relevant domestic standards. It can be adapted to the interfaces of mainstream American 15kV/24kV power distribution equipment to meet the conversion needs of equipment and T-type connectors.
III. Technical Parameters
| Parameter categories | project | Technical indicators |
| Rated electrical parameters | Rated voltage (Ue) | 15kV/24kV (Applicable to 10kV/20kV systems, maximum operating voltage 17.5kV/24kV) |
| Rated current (Ie) | 600A | |
| Rated frequency (fn) | 50Hz/60Hz | |
| Power frequency withstand voltage | 42kV/5min (15kV dry test), 65kV/5min (24kV dry test), no breakdown, no flashover. | |
| Lightning impulse withstand voltage | 95kV (15kV peak) and 125kV (24kV peak), no breakdown and no flashover. | |
| Partial discharge quantity | ≤10pC (below 1.5U₀) | |
| Rated short-circuit withstand current | 20kA/2s (25kA/2s optional, depending on system requirements) | |
| Contact resistance | ≤50μΩ | |
| Structural and material parameters | Main material | EPDM (ethylene propylene diene monomer) rubber (insulating layer), tin-plated copper (conductive contacts) |
| Protection level | IP67 | |
| Interface Standard | Both ends are 15kV/24kV 600A standard cable accessory interfaces. | |
| Environmental parameters | Applicable altitude | ≤2000m (Customization available for high altitudes) |
| Ambient temperature | -40℃/ +90℃ (operating temperature), -40℃/ +70℃ (storage temperature) | |
| relative humidity | ≤100% (no condensation) | |
| Seismic resistance level | Level 8 | |
| Implementation Standards | IEEE 386, GB/T 12706, DL/T 404, GB/T 11022 |
IV. Scope of Application
- Applicable voltage levels : 10kV/ 15kV/20kV/ 24kV AC medium voltage power distribution systems, compatible with cable accessory interfaces with a maximum operating voltage of 17.5kV/24kV.
- Applicable equipment scenarios :
- The bushing interface of 15kV/24kV American-style ring main unit, box-type substation, cable branch box, American-style box-type transformer and other power distribution equipment serves as the transition component between T-type cable joints and equipment;
- Used in conjunction with T-type cable connectors, sleeve seats, and elbow-type connectors to construct complete detachable cable terminals and line transfer interfaces;
- Urban power distribution network cable lines, power distribution systems for industrial and mining enterprises, and American-style power distribution equipment interfaces for new energy (photovoltaic/wind power) substations;
- Interface adapters for American-style power distribution equipment in various scenarios, including indoor/outdoor power distribution rooms, underground utility tunnels, and cable tunnels.
- Function and Application : Enables insulated and sealed connection between T-type cable joints and equipment bushings/cable accessories, combining conductive connection and sealing protection functions, providing a safe and reliable interface conversion solution for American medium-voltage power distribution systems.
V. Usage Conditions
1. Normal operating conditions
- Altitude: ≤2000m;
- Ambient temperature: -40℃~+90℃; equipment operating temperature complies with relevant standards.
- Relative humidity: ≤100% (no condensation);
- Environmental conditions: No corrosive gases, no flammable or explosive media, no severe vibration or impact;
- Installation method: Compatible with standard 15kV/24kV 600A interface, horizontal or vertical installation is acceptable, and the installation space must meet the operation requirements.
2. Special usage conditions (customization required)
- The altitude exceeds 2000m;
- The ambient temperature exceeds the range of -40℃ to +90℃;
- Severely polluted, salt spray, and chemically corrosive environments;
- High vibration and high impact conditions;
- Non-standard interface specifications and special adapter length requirements;
- High level of contamination.
VI. Installation and Maintenance
1. Installation Requirements
- Before installation, inspect the product’s appearance for cracks, damage, bubbles, and ensure the insulation surface is undamaged and all accessories are present.
- Clean the surface of the interface to be connected, removing oil, dust, and foreign objects, and ensure that the interface is dry and clean.
- Apply a special silicone grease lubricant evenly to the inner walls of both ends of the connector to avoid damaging the insulation layer during installation.
- Slowly push one end of the connector into the equipment sleeve/cable accessory interface to ensure proper installation, then align the T-connector with the other end of the connector to lock the positioning structure.
- After installation, check that the connectors are securely installed, without looseness or tilting, and that the interfaces are reliably sealed.
2. Maintenance Requirements
- Regularly inspect the appearance of the connectors; check for cracks, discharge marks, and dirt accumulation, and ensure that the connections at both ends are secure and not loose.
- Regularly test the insulation resistance to ensure that the performance meets the requirements and to detect potential faults in a timely manner.
- Clean the surface of the connector to remove dust and dirt, and keep the insulating surface dry and clean to avoid corrosion from oil and chemicals.
- If any abnormalities such as cracks, damage, discharge, or overheating occur in the connector or accessories, stop using them immediately and replace them. It is strictly forbidden to operate them while they are malfunctioning.
- Special insulated tools must be used for plugging and unplugging accessories. It is strictly forbidden to operate live interfaces with bare hands. Power distribution safety regulations must be strictly followed during operation.
VII. Precautions
- The product must be installed, debugged, and maintained by professional electrical personnel with medium-voltage power distribution construction qualifications. Operation by non-professional personnel is strictly prohibited.
- The product must be used with the corresponding specifications of equipment sleeves, T-type cable connectors, and cable accessories. It is strictly forbidden to use interfaces with different voltage or current ratings, otherwise it will lead to insulation failure and safety accidents.
- The connector must not be disassembled or modified without authorization, otherwise the warranty and safety guarantee will be lost. It is strictly forbidden to use non-special tools to forcibly install or disassemble it.
- When storing, it should be placed in a dry, ventilated, and cool environment, avoiding direct sunlight, high temperature, humidity, and compression. It is strictly forbidden to contact with sharp objects that may damage the insulation layer.
- When operating accessories on live circuits, it is essential to strictly adhere to power distribution safety regulations, implement appropriate safety precautions, and strictly prohibit any unauthorized operations.
VIII. Model Description
| Model Identification | meaning |
| JY | Product series code |
| TTL | T-type connector series code |
| 15kV/24kV | Applicable system voltage levels, maximum operating voltage 17.5kV/24kV |
| 600A | Adapter interface current rating |
| Deadbreak T Connector | Non-load-breaking type T-connector, used as a transition connection component for T-type cable joints. |
IX. Implementation Standards and Certification
- International Standard: IEEE 386 “Medium Voltage Detachable Cable Connector Standard”;
- National standards: GB/T 12706 “Extruded insulated power cables and accessories with rated voltage of 1kV (Um=1.2kV) to 35kV (Um=40.5kV)”, GB/T 11022 “Common technical requirements for high voltage switchgear and controlgear standards”, DL/T 404 “3.6kV~40.5kV AC metal-enclosed switchgear and controlgear”;
- The product has passed the type test of the National High Voltage Electrical Apparatus Quality Supervision and Inspection Center and meets national electrical safety standards.
X. After-sales service
- Product warranty period: 18 months from the date of manufacture, or 12 months from the date of commissioning (whichever comes first).
- During the warranty period, products will be repaired or replaced free of charge if quality issues arise.
- We provide technical support, installation guidance, and customized services (adaptation to special specifications and working conditions).
Document Description
The technical parameters in this manual are based on standard operating conditions. Special operating conditions need to be customized according to actual needs. The final specifications shall be subject to the product technical agreement and type test report.
Appendix: Product outline diagram
