JY MP□-15kV 200A Multi-Circuit Junction Busbar
Product Overview
JY MP□-15kV 200A multi-circuit busbar (available in 2-way / 3-way / multi-way configurations, Loadbreak Junction Busbar) is a separable cable junction accessory designed for 15kV (10kV class) medium-voltage power distribution systems. Featuring a fully insulated, fully sealed, and touch-safe construction, it enables parallel busbar connections for multiple cable interfaces. Compatible with elbow cable connectors, surge arresters, grounding devices, and other accessories, it forms a “multi-way parallel” distribution interface that integrates insulation isolation, busbar connectivity, and ground protection functions. Widely applied in ring main units, pad-mounted transformer stations, cable junction boxes, and similar equipment, it serves as a critical component for line paralleling and current collection in medium-voltage distribution systems.
Product Features
Electrical and Insulation Performance
Manufactured from high-purity EPDM (Ethylene Propylene Diene Monomer) rubber via integral injection molding, with no seams or air gaps, delivering outstanding insulation performance. Capable of withstanding the rated voltage and transient overvoltages of 15kV systems, meeting the maximum operating voltage requirement of 17.5kV for 10kV systems, with sufficient insulation margin.
Incorporates an internal electric field optimization structure and stress control layer to achieve uniform field distribution and effectively suppress partial discharge. Long-term operation poses no risk of electrical erosion or dielectric breakdown; partial discharge level ≤10 pC (at 1.5U₀).
The internal copper busbar offers excellent conductivity, low contact resistance, minimal heat generation during long-term operation, and superior corrosion and oxidation resistance. Capable of simultaneously carrying 200A across multiple circuits with stable electrical performance.
Compatible with grounding lead-out wires to ensure reliable earthing, effectively dissipating fault currents and induced voltages, thereby enhancing system safety.
Structural and Safety Features
The fully insulated, fully sealed, touch-safe construction provides high outer insulation integrity. The external surface may be touched during live operation without risk of electric shock, ensuring the safety of operations and maintenance personnel.
The integrated multi-circuit design is available in 2-way, 3-way, 4-way, and other configurations. Compatible with standard American / European 15kV equipment bushing interfaces, it allows simultaneous connection of multiple cable accessories for line current collection. The compact structure enables convenient installation without additional adapter components.
Anti-miswiring and anti-misconnection design with standardized interface dimensions ensures compatibility only with accessories of the corresponding rating, preventing cross-rating mixing. The integrated positioning and locking mechanism prevents loosening or disengagement after installation.
The rational interface layout provides adequate operating clearance, enabling convenient insertion and extraction of accessories without specialized tools for installation and maintenance.
Environmental and Weather Resistance
Excellent weatherability across a wide temperature range of -40°C to +90°C, with no degradation of rubber elasticity or insulation performance at extreme temperatures, and no risk of cracking or embrittlement. Suitable for both outdoor and indoor applications.
Moisture-proof, waterproof, dust-proof, and salt-spray resistant, with IP67 protection rating. Capable of sustained stable operation in harsh environments including buried, humid, and high-dust conditions, unaffected by rainwater or condensation ingress.
Anti-aging, UV-resistant, and ozone-corrosion resistant, with a service life exceeding 30 years. Maintenance-free operation reduces long-term operational costs.
Mechanical and Compatibility Features
High mechanical strength with impact and vibration resistance. Capable of withstanding mechanical stresses during transportation, installation, and operation without risk of deformation or damage. Seismic resistance rating: Grade 8.
Compatible with standard 15kV 200A equipment bushing interfaces. Each circuit output terminal is universally interchangeable with elbow cable connectors, surge arresters, and grounding devices of the same rating, providing strong universality.
Standardized interfaces compliant with IEEE 386 and relevant domestic standards. Compatible with bushing interfaces of mainstream 15kV ring main units, pad-mounted transformer stations, and cable junction boxes to fulfill multi-circuit line busbar requirements.
Technical Parameters
| Parameter Category | Item | Technical Specification |
| Rated Electrical Parameters | Rated Voltage (Ue) | 15kV (applicable to 10kV systems; maximum operating voltage 17.5kV) |
| | Rated Current (Ie) | 200A (per circuit); multi-circuit parallel operation | |
| | Rated Frequency (fn) | 50Hz / 60Hz | |
| | Power-Frequency Withstand Voltage | 42kV / 5 min (dry test), 38kV / 5 min (wet test); no breakdown, no flashover | |
| | Lightning Impulse Withstand Voltage | 95kV (peak); no breakdown, no flashover | |
| | Partial Discharge Level | ≤10 pC (at 1.5U₀) | |
| | Rated Short-Circuit Withstand Current | 16kA / 2s (optional: 20kA / 2s, matched to system requirements) | |
| | Contact Resistance | ≤100 μΩ (per circuit) | |
| Structural and Material Parameters | Main Body Material | EPDM rubber (insulation layer); tin-plated copper (busbar / conductive contact components) |
| | Protection Rating | IP67 | |
| | Interface Standard | 1 input terminal (15kV American-standard bushing interface); multiple output terminals (15kV 200A standard accessory interfaces) | |
| | Grounding Method | Compatible with yellow-green dual-color grounding lead-out wire for direct earthing | |
| Environmental Parameters | Applicable Altitude | ≤2,000 m (high-altitude customization available) |
| | Ambient Temperature | -40°C to +90°C (operating); -40°C to +70°C (storage) | |
| | Relative Humidity | ≤100% (non-condensing) | |
| | Seismic Resistance Rating | Grade 8 | |
| Applicable Standards | IEEE 386, GB/T 12706, DL/T 404, GB/T 11022 |
Application Scope
Applicable voltage class: 10kV to 15kV AC medium-voltage distribution systems, compatible with equipment bushing interfaces rated for a maximum operating voltage of 17.5kV.
Applicable equipment and scenarios:
Bushing interfaces of 15kV ring main units, pad-mounted transformer stations, cable junction boxes, American-style pad-mounted transformers, and similar distribution equipment, enabling multi-circuit line current collection;
Used in conjunction with elbow cable connectors, surge arresters, and grounding devices to form multi-circuit cable terminations and multi-circuit surge arrester interfaces;
Urban distribution network cable lines, industrial and mining enterprise distribution systems, and distribution interfaces at renewable energy (photovoltaic / wind power) step-up substations;
Insulated bushing connections for equipment in indoor / outdoor distribution rooms, underground utility tunnels, cable tunnels, and other multi-scenario applications, fulfilling line busbar and branching requirements.
Functional purpose: Provides insulated, sealed, parallel busbar connections between equipment bushings and multiple cable accessories. Incorporates ground protection, insulation isolation, and line current collection functions, delivering a safe and reliable multi-way parallel interface solution for distribution systems.
Operating Conditions
Standard Operating Conditions
Altitude: ≤2,000 m;
Ambient temperature: -40°C to +90°C; equipment operating temperature in accordance with applicable standards;
Relative humidity: ≤100% (non-condensing);
Environmental conditions: free from corrosive gases, flammable or explosive media, and severe vibration or shock;
Installation method: compatible with standard equipment bushing interfaces; horizontal or vertical mounting permissible; installation space must accommodate the operational requirements of all associated accessories.
Special Operating Conditions (Customization Required)
Altitude exceeding 2,000 m;
Ambient temperature outside the -40°C to +90°C range;
Heavily polluted, salt-spray, or chemically corrosive environments;
Severe vibration or high-impact operating conditions;
Non-standard equipment bushing interface dimensions;
Special grounding requirements or high pollution severity class applications.
Installation and Maintenance
Installation Requirements
Prior to installation, inspect the product externally for cracks, damage, or voids; verify the insulation surface is undamaged; check that the grounding lead-out wire (if included) is intact and free of corrosion, and that all accessories are present.
Clean the equipment bushing interface surface, removing grease, dust, and foreign matter to ensure the interface is dry and clean.
Apply a uniform coat of dedicated silicone grease lubricant to the inner wall of the busbar input port to prevent damage to the insulation layer during installation.
Slowly push the busbar onto the equipment bushing interface until fully seated, then engage the positioning lock. If a grounding lead-out wire is included, connect it to the grounding grid; grounding resistance ≤4 Ω.
Connect each circuit output terminal to the corresponding elbow cable connector, surge arrester, or other accessory of the appropriate rating, ensuring accessories are fully seated and anti-withdrawal devices are engaged.
Upon completion of installation, perform insulation resistance testing and power-frequency withstand voltage testing; the unit may be energized only after passing these tests.
Maintenance Requirements
Regularly inspect the busbar externally for cracks, discharge marks, or contamination buildup; verify that the grounding lead-out wire and all circuit accessory connections are secure and free of loosening.
Periodically test insulation resistance to ensure performance meets requirements and to identify latent faults in a timely manner.
Clean the busbar surface to remove dust and contamination, keeping the insulation surface dry and clean; avoid exposure to grease and chemical substances.
If the busbar or any associated accessory exhibits cracks, damage, discharge, or abnormal heating, immediately de-energize and replace the affected component. Continued operation under a fault condition is strictly prohibited.
Insertion and extraction of accessories must be performed using dedicated insulated operating tools. Direct hand contact with energized connectors is strictly prohibited. All operations must strictly comply with distribution system safety regulations.
Precautions
Installation, commissioning, and maintenance must be performed exclusively by qualified electrical personnel holding the relevant medium-voltage distribution construction credentials. Operation by unqualified personnel is strictly prohibited.
The product must be used only with equipment bushings, elbow cable connectors, surge arresters, and other accessories of the corresponding rating. Cross-rating interface mismatch is strictly prohibited, as it will result in insulation failure and safety hazards.
The busbar must not be disassembled or modified without authorization, as doing so will void the warranty and safety assurance. The use of non-dedicated tools to forcibly install or remove connectors is strictly prohibited.
Simultaneous connection of accessories of different voltage classes or current ratings to the circuit output terminals is strictly prohibited; all accessories must be matched to the system parameters.
Store in a dry, well-ventilated, cool environment, away from direct sunlight, high temperatures, moisture, and compressive loads. Contact with sharp objects that could damage the insulation layer is strictly prohibited.
All live-line operations involving associated accessories must strictly comply with distribution system safety regulations, with appropriate safety precautions in place. Non-compliant operations are strictly prohibited.
Model Designation
| Model Identifier | Meaning |
| JY | Product series designation |
| MP | Multi-circuit busbar series designation |
| □ | Number of circuits (2 / 3 / 4, representing 2-way / 3-way / 4-way) |
| 15kV | Rated voltage class; compatible with 15kV systems; maximum operating voltage 17.5kV |
| 200A | Rated current class; compatible with 200A per circuit |
| Loadbreak junction busbar | Loadbreak-type junction busbar; multi-way parallel insulated connection accessory for equipment bushing interfaces |
Applicable Standards and Certifications
International standard: IEEE 386, Standard for Separable Insulated Connector Systems for Power Distribution Systems Above 600V;
National standards: GB/T 12706, Power cables with extruded insulation and their accessories for rated voltages from 1 kV (Um = 1.2 kV) up to 35 kV (Um = 40.5 kV); GB/T 11022, Common specifications for high-voltage switchgear and controlgear standards; DL/T 404, AC metal-enclosed switchgear and controlgear for rated voltages of 3.6 kV to 40.5 kV;
The product has passed type testing at the National High-Voltage Electrical Apparatus Quality Supervision and Inspection Center and complies with national electrical safety standards.
After-Sales Service
Product warranty period: 18 months from the date of manufacture, or 12 months from the date of commissioning, whichever occurs first;
Free repair or replacement for product quality defects within the warranty period;
Technical support, installation guidance, and customization services available (special ratings, special operating condition adaptations).
Document Notes
The technical parameters in this manual are based on standard operating conditions. Special operating conditions require customization based on actual requirements. The product technical agreement and type test reports shall prevail as the definitive reference.
Appendix: Product Outline Drawing