JRSY-35 35kV Heat Shrink Cable Joint Kit
Transmission-level infrastructure leaves no room for joint failures. The JRSY-35 Series handles straight-through splicing of 35kV single-core XLPE cables across the full conductor range from 50mm² to 630mm², covering substations, industrial power corridors, and renewable energy grid-connection projects where a buried joint failure means a major network outage.
What separates this from a standard 35kV cable joint is the dual-layer sleeve architecture — a purpose-designed inner sleeve conforming tightly to the cable insulation geometry, and a heavy outer sleeve providing the mechanical and environmental barrier against soil pressure and groundwater. At 39kV, our verified partial discharge sits at 4.5 to 4.8pC per phase, well under the 10pC limit, which matters because a high voltage cable splice buried in a transmission corridor cannot be routinely inspected.
Built in our 40,000㎡ Hubei facility with full GB/T 12706.4 and JB/T 8144 compliance, we maintain a dedicated production run for this product line. Distributors supplying underground HV cable joint stock for utility-approved frameworks receive consistent batch quality with full type test documentation, OEM packaging, and phased delivery support.
- Zhizheng
- Hubei, China
- 10–20 Days (standard sizes); 20–30 Days (large-volume / OEM orders)
- 30,000 Sets / Month
- Information
35kV Heat Shrink Cable Joint Kit — High-Voltage Splice Manufacturer & Supplier
A 35kV cable joint is not a maintenance item — it is a permanent installation decision. Once buried in a transmission corridor or sealed inside a cable tunnel, it will operate for 30 years without inspection. The Zhizheng JRSY-35 Series is engineered with that reality in mind. Designed for straight-through intermediate jointing of 35kV single-core XLPE insulated power cables (rated at 21/35kV and 26/35kV), these kits combine a precision-fit dual-sleeve construction with verified dielectric performance that has been independently type-tested at the national Power Industry Quality Inspection Centre.
Manufactured in our 40,000㎡ production base in Hubei, China, the JRSY-35 kit series complies with GB/T 12706.4, JB/T 8144, and DL/T 413. It is built to the same material standards as our RSY-35 termination kits, but the joint construction addresses a completely different set of mechanical and sealing demands — as explained below.
Why a 35kV Joint Demands a Different Engineering Approach Than a 10kV Joint
Engineers familiar with our JRSY-10 (10kV) joint kits will notice two significant differences at the 35kV level:
Single-core only construction. At 35kV, network cables are almost universally installed as three separate single-core runs rather than a single three-core cable. Each core gets its own individual joint, which means a complete three-phase splice on a 35kV route requires three JRSY-35 kits. This is standard practice on transmission projects, and our kitting is sized accordingly.
Dual-layer sleeve design. The JRSY-35 includes both an inner sleeve — profiled to the cable insulation geometry for precise electrical field management — and a separate outer sleeve providing the mechanical and environmental seal. At 35kV, the electrical field at the conductor screen cutback is significantly more concentrated than at 10kV. The inner sleeve geometry is what controls that field, preventing the localised stress that would otherwise initiate insulation failure years into service.
Higher test voltages throughout. Impulse rating increases from 105kV (10kV class) to 250kV. DC negative polarity test jumps from -52kV to -156kV. These are not incremental changes — they reflect a fundamentally different insulation class with far less tolerance for material or installation defects.
Core Engineering Features
Ultra-Low Partial Discharge — 4.5 to 4.8pC at 39kV: The accepted standard allows up to 10pC. Our factory batches consistently land between 4.5pC and 4.8pC across all three phases of a combined sample. In a buried high-voltage joint, this margin is not a quality bonus — it is the difference between a 30-year service life and an early failure event.
250kV Impulse Withstand: Ten consecutive shots at 250kV in both positive and negative polarity — no flashover, no breakdown in any phase. This covers the full lightning and switching surge exposure profile of a 35kV transmission network.
Dual-Layer Mechanical Protection: The specially designed inner and outer sleeve combination protects against direct burial soil pressure, cable movement from thermal cycling, and groundwater penetration across the joint body.
Stable from -40°C to +105°C: Covers high-altitude cold climate installations (mountain transmission routes, northern infrastructure projects) as well as high-load operating temperatures in large industrial feeder applications.
Lightweight Field Installation: Despite the heavy-duty electrical performance, the kit components are lightweight enough for single-person handling in a cable trench. Standard heating tools are sufficient — no hydraulic pressing equipment required beyond the conductor connector crimping.
Independent Type Test Performance Data
All data independently verified by the Electrical Equipment Quality Inspection and Testing Center of the Power Industry.
| Test Item | Standard Requirement | Zhizheng Result | Status |
|---|---|---|---|
| Partial Discharge — Initial | At 39 kV ≤ 10 pC | 4.5 pC / 4.6 pC / 4.8 pC (per phase) | Pass |
| Load Cycle Test | 3 cycles at 90°C–95°C (5h heat / 3h cool per cycle) | 3 full cycles completed — no degradation | Pass |
| Partial Discharge — Post Load Cycle | At 39 kV ≤ 10 pC | 4.6 pC / 4.8 pC / 4.8 pC (per phase) | Pass |
| Impulse Voltage Test | 250 kV × 10 shots, both polarities, no breakdown | 250 kV × 10 shots — no flashover in any phase | Pass |
| 15 min DC Voltage (Negative) | -156 kV / 15 min, no breakdown | -156 kV / 15 min — no flashover or breakdown | Pass |
| 4h Power Frequency Voltage | 104 kV / 4 h, no breakdown | 104 kV / 4 h — no breakdown in any phase | Pass |
| Visual Inspection | No cracks, no deformation | Clean surface — no cracks or deformation | Pass |
Model Selection — JRSY-35 Series
All models are straight-through intermediate joints for 35kV single-core XLPE cables. For three-phase jointing, order three individual kits of the same size. Custom configurations available on request.
| Model | Description | Conductor Cross-Section (mm²) |
|---|---|---|
| JRSY-35 / 1×1 | 35kV Heat-Shrinkable Single-Core XLPE Cable Straight-Through Joint | 50 – 120 |
| JRSY-35 / 1×2 | 35kV Heat-Shrinkable Single-Core XLPE Cable Straight-Through Joint | 150 – 240 |
| JRSY-35 / 1×3 | 35kV Heat-Shrinkable Single-Core XLPE Cable Straight-Through Joint | 300 – 400 |
| JRSY-35 / 1×4 | 35kV Heat-Shrinkable Single-Core XLPE Cable Straight-Through Joint | 500 – 630 |
Typical Project Applications
Grid Transmission Corridors: Long underground 35kV feeder routes between primary substations where drum lengths are insufficient for a continuous run — jointing is the only engineering option.
Renewable Energy Grid Connection: Offshore and onshore wind farms, large-scale solar plants, and battery storage facilities connecting to the 35kV transmission network via underground cable routes with multiple intermediate joints.
Heavy Industrial Power Supply: Steel mills, aluminium smelters, and petrochemical complexes running dedicated 35kV feeders to on-site step-down transformers across large plant footprints.
Urban Transmission Upgrades: City-centre cable tunnels and cable duct banks where overhead transmission is being replaced with underground 35kV infrastructure as part of grid modernisation programmes.
Cable Fault Reinstatement: Emergency repair of third-party damaged 35kV cables on active transmission routes, where the fault section is cut out and the circuit is restored using a pair of JRSY-35 joints bridging a replacement cable section.
Technical & Procurement Questions
Q1: The original product page listed indoor and outdoor variants with the same model numbers. Which is correct?
A: The JRSY-35 is a straight-through intermediate joint. Unlike termination kits — where indoor (NRSY) and outdoor (WRSY) versions have physically different rain shed components — a straight-through joint is installed underground or inside a cable tunnel and does not require an indoor/outdoor distinction. The four JRSY-35 models are differentiated only by conductor cross-section. If you received conflicting information from our previous product listings, please contact us directly and we will confirm the correct specification for your application.
Q2: We are jointing a three-phase 35kV circuit. How many kits do we need per joint position?
A: Three kits per joint position — one for each single-core phase conductor. On a standard 35kV underground route, a single joint bay contains three individual straight-through joints installed in parallel. We can supply all three kits in a single packaged consignment if preferred, with phase identification labelling to simplify site management.
Q3: Can the JRSY-35 be used with both copper and aluminium conductors?
A: Yes. The heat-shrink components are compatible with both copper and aluminium conductor cables. The conductor connector inside the joint (compression ferrule) must match the conductor material — copper-to-copper, aluminium-to-aluminium, or bimetallic where transitioning between the two. We can supply the appropriate compression connectors as a kit addition. Send us your cable specification and we will confirm the correct connector reference before you order.
Q4: Do you hold stock for urgent dispatch on 35kV joint kits?
A: Yes. We maintain production stock across the four standard JRSY-35 sizes to support urgent fault reinstatement requirements. Transmission-level cable faults are time-critical events — our logistics team is set up to process emergency orders with priority dispatch. Contact us with your required models and quantities and we will confirm availability and the earliest ship date within two hours.
Supplying a Complete 35kV Cable Route? We Cover Every Accessory
A complete 35kV underground cable installation typically requires straight-through joints at intermediate drum-length positions plus termination kits at each circuit end. Zhizheng manufactures both — the JRSY-35 joint kits covered on this page, and the WRSY-35 / NRSY-35 termination kits for the cable ends. One manufacturer, one set of type test documents, one commercial relationship.
Send us your cable route drawing or bill of materials. We will return a complete accessory schedule with factory pricing within 24 hours. Contant now!
