JDXNF2-35W(G)(L) 35kV Outdoor Oil-Immersed Voltage Transformer

Product Overview

The JDXNF2-35W(G)(L) voltage transformer is an outdoor oil-immersed single-phase measurement device engineered for 35kV high-voltage power systems with enhanced anti-pollution performance. This advanced voltage transformer features oil-immersed insulation system that provides exceptional thermal dissipation for continuous high-load operation in harsh outdoor environments. The JDXNF2-35W(G)(L) series includes multiple configurations with flexible secondary outlet options (side outlet or top outlet with 5/7 holes) to accommodate various installation requirements.

The JDXNF2-35W(G)(L) delivers flexible voltage measurement solutions with multiple configurations: standard ratio 35/√3 : 0.1/√3 : 0.1/3V for basic voltage transformation, or enhanced ratio 35/√3 : 0.1/√3 : 0.1/√3 : 0.1/3V with residual voltage winding for ground fault detection and neutral point monitoring. Multiple accuracy classes (0.2, 0.5, 1.0, 3P) accommodate precision metering to protection requirements, with thermal limit output up to 1000VA (standard) or 2×500VA (dual residual winding) ensuring reliable performance under heavy burden conditions. The oil-immersed construction provides superior thermal dissipation compared to epoxy cast-resin alternatives, while the fully enclosed design prevents oil aging and extends service life. Anti-pollution grades W (Grade II) and G (Grade III) ensure reliable performance in moderately to heavily polluted environments. Wide operating temperature range (-40°C to +40°C) and compliance with GB20840.3-2013 and IEC61869-3:2011 standards ensure reliable performance across diverse applications.

Product Display

JDXNF2-35W(G)(L) voltage transformer

JDXNF2-35W(G)(L) voltage transformer application

Application Position

The JDXNF2-35W(G)(L) is installed in outdoor substations, high-voltage switching stations, and transmission networks where reliable voltage measurement is required with superior thermal performance and anti-pollution capability. The oil-immersed insulation system provides exceptional thermal dissipation for continuous high-load operation, making it ideal for applications where transformers operate near their thermal limits. The fully enclosed oil box construction prevents oil aging and extends service life, reducing maintenance requirements. Anti-pollution grades W (Grade II) and G (Grade III) ensure reliable performance in moderately to heavily polluted environments. Typical installation includes concrete foundation mounting with proper grounding and clearance for maintenance access. The oil-immersed construction withstands harsh outdoor conditions including extreme temperatures (-40°C to +40°C), humidity, and pollution.

Main Applications

35kV outdoor substations requiring high thermal capacity
High-voltage transmission line voltage monitoring
Industrial power distribution systems with continuous heavy loads
Renewable energy substations (wind farms, solar plants)
Rural electrification projects with outdoor distribution
Utility networks requiring ground fault detection
Applications with moderately to heavily polluted environments (W/G grades)
High-burden applications requiring 1000VA thermal limit output
Extreme temperature environments (-40°C to +40°C)

Application Case Studies

Application Scenario 1: Extreme Temperature Outdoor Substation
Utilities deploy JDXNF2-35W(G)(L) oil-immersed voltage transformers in 35kV outdoor substations where extreme temperature variations require superior thermal performance. The oil-immersed insulation system provides exceptional thermal dissipation, allowing the transformer to operate reliably in ambient temperatures ranging from -40°C to +40°C. The 1000VA thermal limit output ensures reliable performance even under heavy burden conditions in high ambient temperatures. The fully enclosed oil box construction prevents oil aging, extending service life and reducing maintenance requirements compared to open-type designs. Multiple secondary outlet configurations (side outlet or top outlet with 5/7 holes) provide installation flexibility for various substation layouts.

Application Scenario 2: Ground Fault Detection in Industrial Networks
Industrial facilities with 35kV distribution networks require reliable ground fault detection to prevent equipment damage and ensure personnel safety. The JDXNF2-35W(G)(L) model with residual voltage winding (35/√3 : 0.1/√3 : 0.1/√3 : 0.1/3V ratio) provides dedicated ground fault detection capability through the open-delta secondary winding configuration. The residual voltage winding detects zero-sequence voltage during ground faults, enabling protective relays to quickly isolate faulty sections and prevent cascading failures. The oil-immersed insulation system provides superior thermal performance for continuous operation, while the fully enclosed design prevents oil aging and extends service life. Anti-pollution grade G (Grade III) ensures reliable performance in industrial environments with heavy pollution, while the 100VA 3P accuracy class provides reliable protection performance during fault conditions.

Application Fit

Suitable For

Outdoor 35kV voltage measurement applications
High thermal capacity requirements (1000VA limit output)
Continuous heavy-load operation
Ground fault detection applications (with residual winding)
Moderately to heavily polluted environments (W/G grades)
Applications requiring superior thermal dissipation
High-voltage transmission and distribution networks
Industrial facilities with 35kV distribution systems
Extreme temperature environments (-40°C to +40°C)

Not Recommended For

Indoor installation applications (use indoor-rated models)
Current measurement applications (use CT instead)
High-voltage systems above 40.5kV (use higher voltage class models)
Applications requiring maintenance-free operation (use epoxy cast-resin models)
Space-constrained installations (oil-immersed transformers are larger)
Applications requiring compact design (use epoxy cast-resin models)

Installation Conditions

Installation position: Outdoor substations, switching stations, or transmission networks
Ambient temperature: -40°C to +40°C
Altitude: ≤ 1000m (standard), higher altitude available on request
Insulation: Oil-immersed (superior thermal dissipation)
Frequency: 50Hz or 60Hz
Phase configuration: Single-phase (use three units for three-phase systems)
Anti-pollution grade: W (Grade II) or G (Grade III)
Enclosure: Fully enclosed oil box (prevents oil aging)
Maintenance: Periodic oil testing and seal inspection required
Secondary outlet: Side outlet or top outlet (5/7 holes)

Technical Parameters

The JDXNF2-35W(G)(L) series includes outdoor oil-immersed single-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 Ratio (kV)	Accuracy Class & Rated Output (VA)	Thermal Limit Output (VA)	Insulation Level (kV)
JDXNF2-35W(G) (Standard)	35/√3 : 0.1/√3 : 0.1/3	0.2/3P: 50/100 0.5/3P: 100/100 1.0/3P: 150/100	1000	40.5/80/185
JDXNF2-35W(G) (With residual winding)	35/√3 : 0.1/√3 : 0.1/√3 : 0.1/3	0.2/0.5/3P: 30/40/100	2×500	40.5/80/185
JDXNF2-35W(G)(L) (Enhanced)	35/√3 : 0.1/√3 : 0.1/3	0.2/3P: 75/100 0.5/3P: 150/100 1.0/3P: 200/100	1000	40.5/80/185
JDXNF2-35W(G)(L) (Enhanced with residual)	35/√3 : 0.1/√3 : 0.1/√3 : 0.1/3	0.2/0.5/3P: 40/50/100	2×500	40.5/80/185

Note 1: JDXNF2-35W(G) – Standard voltage transformation for metering and protection applications.

Note 2: JDXNF2-35W(G) with residual winding – Includes residual voltage winding for ground fault detection and neutral point monitoring.

Note 3: JDXNF2-35W(G)(L) – Enhanced configuration with higher rated output for heavy-load applications.

Note 4: JDXNF2-35W(G)(L) with residual winding – Enhanced configuration with dual residual windings for redundant ground fault detection.

Note 5: Anti-pollution grades: W (Grade II) for moderate pollution, G (Grade III) for heavy pollution.

Note 6: Rated output and its relative accuracy class only one alternative per transformer.

Note 7: If user’s data go beyond the above-mentioned scopes, they may be subject to an agreement between manufacturer and purchaser.

Installation

Dimension Reference

JDXNF2-35W(G)(L) voltage transformer dimension drawing 1

Overall dimensions vary by configuration and secondary outlet type. Standard configuration: Height 1085±5mm, Base width 408mm, Box width 368mm. Secondary outlet options: side outlet (standard) or top outlet (5 holes or 7 holes). Weight: approximately 126-143kg depending on configuration. Mounting: 4×M12 mounting bolts on base plate. Clearance: Minimum 600mm around transformer for maintenance access and oil sampling. Top terminals: High-voltage bushings with M16 studs. Secondary outlet: Bottom terminal box or top terminal box for cable connection.

Wiring Diagram

JDXNF2-35W(G)(L) voltage transformer wiring diagram

JDXNF2-35W(G)(L) supports multiple wiring configurations: Y/Y/Δ connection (four windings) for comprehensive metering and protection, or Y/Δ connection (three windings) for standard voltage transformation. Primary terminals A, N connect to 35kV system. Secondary outputs 1a1n, 2a2n, 3a3n for metering and protection, da/dn for open-delta ground fault detection. Ensure proper polarity and phase sequence during installation.

Installation Guidelines

Foundation: Install on a level concrete foundation capable of supporting 126-143kg weight. Foundation should be 150mm above ground level to prevent water accumulation and facilitate oil sampling. Use anchor bolts (M12) 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. Ground the transformer base and secondary winding neutral point.
Clearance: Maintain minimum 600mm clearance on all sides for maintenance access, oil sampling, and ventilation. Ensure adequate clearance from live parts according to local electrical codes (typically 400mm for 35kV).
Primary Connection: Connect primary terminals (A, N) to the 35kV power system using appropriate high-voltage conductors or busbars. Ensure proper phase sequence and torque specifications (typically 60 N·m for M16 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, check the oil level indicator to ensure proper oil level. The oil level should be between MIN and MAX marks. If oil level is low, contact manufacturer for oil filling procedure.
Commissioning Tests: Perform insulation resistance test (minimum 1000 MΩ at 20°C), turns ratio test, polarity test, and oil dielectric strength test (minimum 30kV/2.5mm) before energizing. Verify all connections are tight and properly torqued.

Oil-Immersed Insulation Features

Superior Thermal Dissipation: Oil-immersed insulation provides exceptional thermal dissipation, allowing the transformer to operate at higher burden levels without exceeding temperature limits. The oil circulates naturally, transferring heat from the core and windings to the outer tank walls, where it is dissipated to the ambient air.
High Thermal Capacity: The oil-immersed design provides high thermal capacity (1000VA thermal limit output), enabling continuous operation under heavy burden conditions. This is critical for applications where transformers operate near their thermal limits in high ambient temperatures.
Fully Enclosed Construction: The fully enclosed oil box prevents oil aging by minimizing exposure to air and moisture. This extends oil service life and reduces maintenance requirements compared to open-type designs. The sealed construction also prevents contamination from dust and pollutants.
Excellent Dielectric Strength: Transformer oil provides excellent dielectric strength, ensuring reliable insulation between windings and from windings to ground. The oil fills all voids and gaps in the insulation system, providing uniform electric field distribution and preventing partial discharge.
Proven Technology: Oil-immersed transformers have been used for over a century in high-voltage applications, providing a proven track record of reliability and performance. The technology is well-understood, and maintenance procedures are standardized.

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 JDXNF2-35W(G)(L) voltage transformer, consider the following factors:

Model Selection: Choose JDXNF2-35W(G) for standard voltage measurement, or JDXNF2-35W(G)(L) for enhanced rated output. Select model with residual voltage winding if ground fault detection is required
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. Thermal limit output is 1000VA for standard models or 2×500VA for models with residual winding
Environmental Conditions: Verify ambient temperature (-40°C to +40°C), altitude (≤1000m standard), and anti-pollution grade (W for moderate, G for heavy pollution) match your installation environment
Secondary Outlet Configuration: Choose side outlet (standard) or top outlet (5 holes or 7 holes) based on installation requirements and cable routing
Maintenance Capability: Oil-immersed transformers require periodic oil testing and seal inspection. Ensure this aligns with your maintenance strategy and resources
Ground Fault Detection: If ground fault detection is required, select model with residual voltage winding
Thermal Performance: If superior thermal dissipation is required for continuous heavy-load operation, oil-immersed design provides better performance than epoxy cast-resin alternatives

Ordering Information

When ordering the JDXNF2-35W(G)(L) voltage transformer, please specify:

Model: JDXNF2-35W(G) or JDXNF2-35W(G)(L)
Rated voltage ratio (e.g., 35/√3 : 0.1/√3 : 0.1/3kV)
Accuracy class and rated output (e.g., 0.2/3P-50/100VA)
Anti-pollution grade: W (Grade II) or G (Grade III)
Secondary outlet configuration: Side outlet or top outlet (5/7 holes)
Rated frequency (50Hz or 60Hz)
Quantity required
Any special requirements or custom specifications

FAQs

JDXNF2-35W(G) is the standard model with rated output up to 150VA (1.0/3P class). JDXNF2-35W(G)(L) is the enhanced model with higher rated output up to 200VA (1.0/3P class), suitable for heavy-load applications. Both models are available with or without residual voltage winding for ground fault detection.

Oil-immersed transformers require periodic maintenance including oil quality testing (dielectric strength, moisture content, acidity), seal inspection for leaks, bushing inspection, and temperature monitoring. Recommended maintenance intervals are annually for critical applications or every 2-3 years for standard applications. The fully enclosed design reduces maintenance frequency compared to open-type transformers.

Oil-immersed insulation provides superior thermal dissipation, allowing higher thermal capacity (1000VA limit output) and continuous operation under heavy burden conditions. The oil circulates naturally, transferring heat from core and windings to tank walls. Epoxy cast-resin transformers are maintenance-free but have lower thermal capacity and are better suited for space-constrained applications.

W (Grade II) is suitable for moderate pollution environments such as rural areas and light industrial zones. G (Grade III) is recommended for heavy pollution environments such as coastal areas with salt spray, chemical plants, cement factories, and mining operations. Choose G if your installation site is within 10km of coastline or in areas with significant industrial pollution.

For revenue metering applications, accuracy class 0.2 is recommended to ensure precise energy measurement with 50VA rated output (0.2/3P-50/100VA). Class 0.5 (100VA) is suitable for monitoring and general measurement applications. Class 3P (100VA) is used for protection applications where accuracy is less critical than reliability during fault conditions.

With proper installation and regular maintenance, oil-immersed transformers have service life exceeding 30 years. Key factors affecting service life include operating temperature, load conditions, oil quality maintenance, and environmental factors. The fully enclosed design prevents oil aging, extending service life. Regular oil testing and maintenance ensure reliable operation throughout the equipment lifespan.

Standard ratios include 35/√3 : 0.1/√3 : 0.1/3kV and 35/√3 : 0.1/√3 : 0.1/√3 : 0.1/3kV. Custom ratios can be manufactured based on specific project requirements. Please contact our technical team for custom specifications and lead times. Custom ratios may affect accuracy class and rated output capabilities.

The JDXNF2-35W(G)(L) complies with GB20840.3-2013 (Chinese standard) and IEC61869-3:2011 (international standard) for voltage transformers, ensuring compatibility with both domestic and international high-voltage measurement applications. The transformers are tested and certified according to these standards for accuracy, insulation, and thermal performance.