Product Overview
The JSXN-35 voltage transformer is an outdoor oil-immersed three-phase measurement device engineered for 35kV high-voltage power systems. This robust voltage transformer features oil-immersed insulation technology with porcelain bushings, providing superior dielectric strength and thermal dissipation for reliable performance in harsh outdoor environments. The three-phase design enables simultaneous measurement of all three phase voltages in a single unit, eliminating the need for three separate single-phase transformers.
The JSXN-35 delivers comprehensive voltage measurement for energy metering, voltage monitoring, and relay protection applications with multiple accuracy classes (0.2, 0.5, 1.0) and flexible winding configurations (three-winding or four-winding). The oil-immersed construction ensures excellent insulation performance with 40.5/80/185kV insulation level while providing up to 800VA thermal limit output capacity. The integrated oil conservator, level indicator, and drain valve facilitate maintenance and ensure long-term operational reliability. Wide operating temperature range (-40°C to +40°C) makes it suitable for extreme climate conditions from arctic cold to tropical heat.
Product Display
Application Position
The JSXN-35 is installed in outdoor substations, high-voltage switching stations, and transmission networks where reliable three-phase voltage measurement is required under harsh environmental conditions. The oil-immersed insulation system with porcelain bushings provides excellent UV resistance, moisture protection, and pollution tolerance for outdoor operation. The three-phase configuration reduces installation space and wiring complexity compared to three separate single-phase units. Typical installation includes concrete foundation mounting with proper grounding and clearance for maintenance access.
Main Applications
- 35kV outdoor substations and switching stations
- High-voltage transmission line voltage monitoring
- Industrial power distribution systems with outdoor switchgear
- Renewable energy substations (wind farms, solar plants)
- Rural electrification projects with outdoor distribution
- Utility networks requiring three-phase voltage measurement
- Harsh environment applications (extreme temperatures, high pollution)
Application Case Studies
Application Scenario 1: Outdoor Substation Three-Phase Voltage Measurement
Utilities deploy JSXN-35 oil-immersed voltage transformers in 35kV outdoor substations for comprehensive three-phase voltage measurement and protection. The integrated three-phase design eliminates the need for three separate single-phase units, reducing installation space by 60% and wiring complexity. The oil-immersed insulation system with porcelain bushings withstands extreme weather conditions including UV radiation, rain, snow, and industrial pollution. The four-winding configuration provides separate outputs for metering (accuracy class 0.2), protection (3P), and open-delta ground fault detection, ensuring reliable operation under all system conditions.
Application Scenario 2: Transmission Line Voltage Monitoring
High-voltage transmission networks require accurate voltage measurement for system monitoring and control. The JSXN-35 offers multiple accuracy classes (0.2, 0.5, 1.0) to meet different measurement requirements, with up to 800VA thermal limit output capacity for driving multiple metering devices and protection relays simultaneously. The oil-immersed construction provides superior thermal dissipation, allowing continuous operation at full load even in high ambient temperatures (+40°C). The integrated oil conservator compensates for oil volume changes due to temperature fluctuations, maintaining consistent insulation performance throughout the operating temperature range (-40°C to +40°C).
Application Fit
Suitable For
- Outdoor 35kV voltage measurement applications
- Substations requiring three-phase measurement in single unit
- Harsh environment installations (extreme temperatures, high pollution)
- Applications requiring high thermal capacity (up to 800VA)
- Transmission line voltage monitoring and protection
- Industrial facilities with outdoor medium-voltage switchgear
- Renewable energy substations exposed to weather elements
Not Recommended For
- Indoor installation applications (use indoor-rated models like JDZ9-35Q)
- Current measurement applications (use CT instead)
- High-voltage systems above 40.5kV (use higher voltage class models)
- Applications requiring minimal maintenance (oil-immersed requires periodic oil testing)
- Space-constrained installations where three separate single-phase units cannot fit
Installation 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
- Frequency: 50Hz or 60Hz
- 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
- Seismic resistance: Grade 8 earthquake resistance
- Maintenance: Periodic oil quality testing and seal inspection required
Technical Parameters
The JSXN-35 series includes outdoor oil-immersed three-phase voltage transformers for 35kV systems. Operating temperature -40°C to +40°C, compliant with GB20840.3-2013 and IEC61869-3:2011 standards.
| Model | Rated Voltage (kV) |
Accuracy Class & Rated Output (VA) |
Thermal Limit Output (VA) |
Insulation Level (kV) |
|---|---|---|---|---|
| JSXN-35 (Three-winding) |
35/√3 : 0.1/√3 : 0.1/3 | 0.2/3P: 3×(60/100) 0.5/3P: 3×(150/100) 1.0/3P: 3×(200/100) |
800 | 40.5/80/185 |
| JSXN-35 (Four-winding) |
35/√3 : 0.1/√3 : 0.1/√3 : 0.1/3 | 0.2/0.5/3P: 3×(50/50/100) |
600 | 40.5/80/185 |
Note 1: Three-winding configuration (35/√3 : 0.1/√3 : 0.1/3) – Standard Y/Y/△ connection for metering, protection, and ground fault detection.
Note 2: Four-winding configuration (35/√3 : 0.1/√3 : 0.1/√3 : 0.1/3) – Enhanced configuration with dual secondary outputs for separate metering and protection circuits.
Note 3: Rated output values are per-phase (3× indicates three-phase total).
Note 4: Rated output and its relative accuracy class only one alternative per transformer.
Note 5: If user’s data go beyond the above-mentioned scopes, they may be subject to an agreement between manufacturer and purchaser.
Installation
Dimension Reference
Overall dimensions: Height 1180±15mm, base width 770mm, total length 1115±20mm. Weight: approximately 250kg (oil-filled). Mounting: Concrete foundation with anchor bolts. Clearance: Minimum 800mm around transformer for maintenance access.
Wiring Diagram
Three-winding: Primary terminals A, B, C connect to star configuration with neutral N. Secondary outputs a, b, c for metering (star connection with neutral n), da/dn for open-delta ground fault detection. Four-winding: Additional secondary outputs 2a, 2b, 2c with neutral 2n for separate protection circuit.
Installation Guidelines
- Foundation: Install on a level concrete foundation capable of supporting 250kg weight. Foundation should be 100mm above ground level to prevent water accumulation. Use anchor bolts (M16) secured into foundation with minimum 200mm embedment depth.
- Grounding: Connect the grounding terminal (M10) to the substation grounding grid using copper conductor with minimum 50mm² cross-section. Ensure grounding resistance is less than 4 ohms.
- Clearance: Maintain minimum 800mm clearance on all sides for maintenance access and ventilation. Ensure adequate clearance from live parts according to local electrical codes (typically 400mm for 35kV).
- Primary Connection: Connect primary terminals (A, B, C) to the 35kV power system using appropriate high-voltage conductors or busbars. Ensure proper phase sequence and torque specifications (typically 50 N·m for M12 bolts).
- Secondary Connection: Connect secondary terminals to metering devices, protection relays, or monitoring equipment according to the wiring diagram. Use shielded cables for secondary circuits to minimize electromagnetic interference. Ensure proper termination and labeling.
- Oil Level Check: Before energizing, verify oil level is within the normal range indicated by the oil level indicator. If oil level is low, top up with compatible transformer oil (typically 25# or 45# mineral oil).
- Commissioning Tests: Perform insulation resistance test (minimum 1000 MΩ at 20°C), turns ratio test, and polarity test before energizing. Verify all connections are tight and properly torqued.
Oil-Immersed Insulation Features
- Superior Thermal Dissipation: Oil-immersed construction provides excellent heat transfer, allowing continuous operation at full load even in high ambient temperatures (+40°C). Oil circulation naturally dissipates heat generated by core and winding losses.
- Excellent Dielectric Strength: Transformer oil provides superior insulation properties with dielectric strength exceeding 40kV/2.5mm. Oil fills all voids and gaps, eliminating partial discharge sites and ensuring uniform voltage distribution.
- Self-Healing Properties: Oil-immersed insulation can recover from minor electrical stress without permanent damage. Oil quality can be maintained through periodic testing and filtration, extending transformer service life.
- Temperature Compensation: Integrated oil conservator compensates for oil volume changes due to temperature fluctuations (-40°C to +40°C), maintaining consistent oil level and insulation performance throughout the operating range.
- Long Service Life: Properly maintained oil-immersed transformers have service life exceeding 30 years. Regular oil quality testing and maintenance ensure reliable operation throughout the equipment lifespan.
Maintenance Requirements
- Oil Quality Testing: Perform dissolved gas analysis (DGA) and dielectric strength test annually. Oil dielectric strength should exceed 30kV/2.5mm. Replace or filter oil if dielectric strength falls below specification.
- Seal Inspection: Check all gaskets and seals annually for leaks. Replace any deteriorated seals immediately to prevent moisture ingress and oil contamination.
- Bushing Inspection: Inspect porcelain bushings annually for cracks, chips, or contamination. Clean bushings with approved solvent if contamination is present. Replace damaged bushings immediately.
- Oil Level Monitoring: Check oil level indicator monthly. Oil level should remain within normal range across all operating temperatures. Investigate and correct any persistent low oil level conditions.
- Connection Tightening: Check all electrical connections annually and re-torque to specifications. Loose connections can cause overheating and equipment failure.
Standards
- GB20840.3-2013 (Instrument transformers – Part 3: Inductive voltage transformers)
- IEC61869-3:2011 (Instrument transformers – Part 3: Inductive voltage transformers)
- Customer-specific requirements available on request
Selection Guide
When selecting the JSXN-35 voltage transformer, consider the following factors:
- Winding Configuration: Choose three-winding (Y/Y/△) for basic metering and protection, or four-winding for dual secondary outputs and enhanced redundancy
- Accuracy Class: Choose 0.2 for revenue metering, 0.5 for monitoring applications, 1.0 for general measurement, 3P for protection applications
- Burden Requirements: Ensure the rated output matches the connected load (metering devices, relays) to maintain accuracy. Three-winding configuration offers higher thermal limit (800VA) compared to four-winding (600VA)
- Environmental Conditions: Verify ambient temperature (-40°C to +40°C), altitude (≤1000m standard), and pollution grade match your installation environment
- Maintenance Capability: Oil-immersed transformers require periodic maintenance (oil testing, seal inspection). Ensure maintenance resources are available for long-term operation
- Space Constraints: Three-phase design requires less space than three separate single-phase units, but still requires adequate clearance for maintenance access
Ordering Information
When ordering the JSXN-35 voltage transformer, please specify:
- Model: JSXN-35
- Winding configuration: Three-winding or Four-winding
- Rated voltage ratio (e.g., 35/√3 / 0.1/√3 / 0.1/3 kV)
- Accuracy class and rated output (e.g., 0.2/3P, 3×(60/100)VA)
- Rated frequency (50Hz or 60Hz)
- Quantity required
- Any special requirements or custom specifications