Overview
The JDJ-3/6/10/12 is an oil-immersed single-phase voltage transformer designed for medium-voltage systems rated at 3kV, 6kV, 10kV, and 12kV, operating at 50Hz. It uses oil-immersed insulation with primary and secondary windings wound on a common ring-shaped core, ensuring stable performance in both indoor and outdoor environments.
Available in accuracy classes 0.2, 0.5, 1, and 3, the transformer supports rated outputs from 20VA to 320VA, making it suitable for metering, relay protection, and power quality monitoring. It complies with relevant IEC and GB standards for voltage transformers used in power distribution networks.
Key Ratings Snapshot
| Parameter | Rating |
|---|---|
| System Voltage | 3kV / 6kV / 10kV / 12kV |
| Frequency | 50Hz |
| Insulation Type | Oil-immersed |
| Phase Configuration | Single-phase |
| Accuracy Classes | 0.2 / 0.5 / 1 / 3 |
| Rated Output | 20VA – 320VA |
| Primary Voltage | 3kV / 6kV / 10kV / 12kV |
| Secondary Voltage | 100V (standard) |
| Max Altitude | ≤1000m |
| Cooling Method | Natural oil convection |
| Installation Position | Indoor or outdoor |
| Application | Metering, relay protection, voltage monitoring |
Construction
The JDJ series features a robust oil-immersed design with both primary and secondary windings mounted concentrically on a single ring-shaped magnetic core. The entire assembly is sealed within a welded steel tank filled with insulating oil, which provides both dielectric strength and thermal dissipation. The compact construction weighs approximately 46.5kg and includes porcelain bushings for high-voltage connections and terminal blocks for secondary wiring. This design ensures long-term reliability, minimal maintenance, and consistent performance under continuous load conditions in medium-voltage power systems.
Technical Parameters
Service Conditions
- Installation position: Indoor switchgear or outdoor substation
- Ambient temperature: -5°C to +40°C
- Altitude: ≤ 1000m
- Relative humidity: ≤ 85% at 20°C
- Insulation: Oil-immersed
- Frequency: 50Hz
- Vibration: Passed 0.4g intensity test
Technical Parameters
The JDJ series is an oil-immersed single-phase voltage transformer designed for 3kV, 6kV, 10kV, and 12kV systems. It features oil-immersed insulation, operates within a temperature range of -5°C to +40°C, and is suitable for installations up to 1000m altitude.
| Type | Rated
voltage ratio (V) |
Corresponding (VA) | limit
output (VA) |
Power
frequency voltage (kV) |
Weight
(kg) |
|||
|---|---|---|---|---|---|---|---|---|
| 0.2 | 0.5 | 1 | 3 | |||||
| JDJ-3 | 3000/100 | 20 | 30 | 50 | 120 | 240 | 24 | 46.5 |
| JDJ-6 | 6000/100 | 30 | 50 | 80 | 200 | 400 | 32 | |
| JDJ-10 | 10000/100 | 40 | 80 | 150 | 320 | 640 | 42 | |
| JDJ-12 | 11000/110 | 40 | 80 | 150 | 320 | 640 | 42 | |
Installation & Wiring
Installation Diagram
The JDJ-3/6/10/12 transformer is mounted on a flat surface using four Ø10mm bolts through the base mounting holes (230 x 205mm footprint). Ensure adequate clearance around the unit for ventilation and maintenance access, especially when installed in indoor switchgear or outdoor substations.
Wiring Diagram
Primary terminals are marked A and N, connected to the system voltage via fuses. Secondary terminals are labeled a and n, supplying metering and protection circuits. The secondary neutral point (n terminal) must be solidly grounded to ensure safety and measurement accuracy. For three-phase applications, two units are typically connected in V-configuration.
Selection & FAQs
Selection Guide
- Select the model based on system voltage: JDJ-3 for 3kV, JDJ-6 for 6kV, JDJ-10 for 10kV, or JDJ-12 for 12kV systems.
- Choose accuracy class according to application needs: 0.2 for high-precision metering, 0.5 for standard metering, 1 for general measurement, or 3 for indication purposes.
- Determine rated output (20–320VA) based on the total burden of connected instruments and devices.
- Decide between single or double secondary winding configuration depending on whether you need one or two independent outputs.
- Specify installation type as either indoor or outdoor to ensure proper enclosure and environmental protection.
Frequently Asked Questions
Q1: Is the JDJ-10 transformer suitable for outdoor substation installation?
Yes, it is suitable for both indoor switchgear and outdoor substations. The oil-immersed insulation ensures reliable performance in ambient temperatures from -5°C to +40°C. Contact us for specific outdoor enclosure requirements.
Q2: Which accuracy class provides the highest burden capacity for JDJ-6?
The 3.0 accuracy class offers the highest burden capacity at 200 VA for the JDJ-6 model. For metering applications requiring higher precision, the 0.2 class supports up to 30 VA. Specify your exact burden needs during ordering.
Q3: When considering altitude, what is the maximum installation limit?
The maximum allowable installation altitude is 1000 meters. It operates at a standard frequency of 50Hz and withstands vibration intensities up to 0.4g. For higher altitude deployments, factory derating confirmation is required.
Q4: How much does a single JDJ-10 unit weigh for logistics planning?
Each JDJ-10 unit weighs 46.5 kg. This standard weight applies across the JDJ-3, JDJ-6, JDJ-10, and JDJ-12 models. Please contact our sales team for detailed packaging dimensions and freight calculations.
Q5: Are custom rated voltage ratios available for non-standard systems?
Standard ratios include 3000/100, 6000/100, 10000/100, and 12000/100. Custom voltage ratios are subject to engineering confirmation and factory approval. Submit your specific system parameters to check feasibility and lead times.
Q6: What applications suit the JDJ-3 oil-immersed voltage transformer?
The JDJ series is specifically designed for 3kV to 12kV power distribution networks. It functions as a single-phase voltage transformer operating at a standard 50Hz frequency. This configuration ensures stable voltage measurement for indoor and outdoor applications.