Overview
The JSXN-35kV is an outdoor oil-immersed three-phase voltage transformer designed for 35kV high-voltage power systems. It utilizes oil-immersed insulation with porcelain bushings to deliver high dielectric strength and efficient thermal dissipation, ensuring reliable operation in demanding outdoor environments.
Available in accuracy classes 0.2, 0.5, and 1.0, the JSXN-35 supports energy metering, voltage monitoring, and relay protection applications. Its three-phase configuration integrates all phase measurements into a single unit, reducing space and wiring complexity. The transformer meets standard insulation levels of 40.5/80/185kV and offers up to 800VA thermal output capacity, suitable for utility substations, transmission networks, and renewable energy installations operating in temperatures from -40°C to +40°C.
Key Ratings Snapshot
| Parameter | Rating |
|---|---|
| System Voltage | 35 kV |
| Insulation Level (LI/AC/SW) | 185/80/40.5 kV |
| Accuracy Classes | 0.2, 0.5, 1.0 |
| Thermal Limit Output | Up to 800 VA |
| Phases | Three-phase |
| Insulation Type | Oil-immersed |
| Bushing Material | Porcelain |
| Winding Configurations | Three-winding or four-winding |
| Operating Temperature Range | -40°C to +40°C |
| Mounting | Outdoor, concrete foundation |
| Oil Conservator | Integrated |
| Ground Fault Detection | Supported (open-delta winding) |
Construction
The JSXN-35kV features a robust cast-resin and oil-immersed construction optimized for outdoor service. The core and windings are fully immersed in insulating oil contained within a sealed steel tank, providing excellent dielectric performance and heat transfer. High-voltage and low-voltage terminals are housed in weather-resistant porcelain bushings that offer superior resistance to UV exposure, moisture ingress, and surface pollution. An integrated oil conservator accommodates thermal expansion and contraction of the insulating oil across the full operating temperature range. The unit includes an oil level indicator and drain valve for routine maintenance, ensuring long-term reliability. All external surfaces are treated for corrosion resistance, and the grounding terminal is clearly marked for safe installation per electrical safety standards.
Technical Parameters
Service Conditions
- Installation position: Outdoor substations, switching stations, or transmission networks
- Ambient temperature: -40°C to +40°C (wider range than indoor models)
- Altitude: ≤ 1000m (standard), higher altitude available on request
- Insulation: Oil-immersed with porcelain bushings
- Phase configuration: Three-phase (single unit)
- Pollution grade: Grade II-IV (suitable for industrial and coastal areas)
- Wind load: Designed to withstand wind speeds up to 70 m/s
Technical Parameters
The JSXN-35kV outdoor oil-immersed three-phase voltage transformer is designed for 35kV systems with oil-immersed insulation and porcelain bushings. It operates within an ambient temperature range of -40°C to +40°C and at altitudes up to 1000m, complying with GB20840.3-2013 and IEC61869-3:2011 standards.
| Type | Rated Voltage (kV) | Accuracy class /
Rated output (VA) |
Max.
output (VA) |
Rated
insulation (kV) |
|---|---|---|---|---|
| JSXN-35 | 35/√3 : 0.1/√3 : 0.1/3 | 0.2/3P-3×(60/100) 0.2/6P-3×(60/100) 0.5/3P-3×(150/100) 0.5/6P-3×(150/100) 1.0/3P-3×(200/100) 1.0/6P-3×(200/100) |
800 | 40.5 / 80 / 185 |
| 35/√3 : 0.1/√3 : 0.1/√3 : 0.1/3 | 0.2/0.5/3P-3×(50/50/100) | 600 |
Installation & Wiring
Outline Dimensions
Overall dimensions: Height 1180±15mm, base width 770mm, total length 1115±20mm. The unit weighs approximately 250kg when oil-filled and is designed for mounting on a concrete foundation using anchor bolts.
Wiring Diagram
The transformer features either three or four secondary windings. Primary terminals A, B, C are connected in a star configuration with neutral N. For metering, secondary outputs a, b, c (with neutral n) are wired in star. An open-delta connection da/dn is provided for ground fault detection. In the four-winding version, an additional set of secondary outputs 2a, 2b, 2c with neutral 2n is available for separate protection circuits.
Selection & FAQs
Selection Guide
- Winding Configuration: Select three-winding (Y/Y/△) for standard metering and protection, or four-winding for dual secondary outputs and added redundancy.
- Accuracy Class: Use class 0.2 for revenue metering, 0.5 for monitoring, 1.0 for general measurement, and 3P for protection applications.
- Burden Matching: Ensure the connected load (meters, relays) does not exceed the rated output—800VA for three-winding, 600VA for four-winding—to maintain accuracy and thermal performance.
- Environmental Suitability: Confirm the installation site meets requirements for ambient temperature (-40°C to +40°C), altitude (≤1000m standard), and pollution grade.
- Maintenance Planning: Account for periodic oil testing, seal inspections, and access space, as oil-immersed units require ongoing maintenance for reliable long-term operation.
Frequently Asked Questions
Q1: Can this 35kV voltage transformer operate in extreme cold?
Yes, it operates in ambient temperatures from -40°C to +40°C. The oil-immersed insulation and porcelain bushings provide dielectric strength for harsh outdoor conditions.
Q2: Which accuracy class suits protective relaying applications?
Select 3P or 6P accuracy classes for protection circuits. These classes provide rated outputs of 100VA per phase under fault conditions. Confirm exact burden with our engineering team.
Q3: What international standards does this outdoor transformer meet?
The JSXN-35kV model complies with GB20840.3-2013 and IEC61869-3:2011 standards. Request specific type test reports and compliance certificates during the procurement phase.
Q4: How does high altitude affect unit installation?
Standard installation is rated for altitudes up to 1000m. For higher elevations, derating or custom insulation design is required. Contact us for site-specific altitude adjustments.
Q5: Where is this three-phase voltage transformer typically applied?
It is designed for outdoor substations, switching stations, and transmission networks. The unit withstands pollution grades II-IV and wind speeds up to 70 m/s.
Q6: Are custom ratios available for specific project needs?
Yes, standard configurations include 0.2 to 1.0 accuracy classes with up to 800VA maximum output. Custom ratio or burden requirements are subject to factory confirmation.
Q7: Do you provide factory testing before shipment?
Routine tests are performed on every unit prior to dispatch. Specific type tests or witness testing are subject to confirmation. Contact our sales team for details.