Overview
The JDZW-20 and JDZW2-20 are outdoor-type, single-phase voltage transformers rated for 20 kV systems. They feature cast-resin (epoxy) insulation, providing robust electrical isolation and environmental protection for reliable operation in exposed outdoor installations.
These units deliver high accuracy of class 0.2 or 0.5, making them suitable for revenue metering, voltage monitoring, and protective relaying in medium-voltage distribution networks. Designed for ungrounded or weak-grounded systems, they comply with IEC 186 and GB 1207-2006 standards, ensuring compatibility with international and domestic grid requirements.
Key Ratings Snapshot
| Parameter | Rating |
|---|---|
| System voltage class | 20 kV |
| Rated frequency | 50 Hz or 60 Hz |
| Rated voltage ratio | 20000/√3 V / 100/√3 V or 20000/√3 V / 100/√3 V / 100/3 V |
| Secondary voltage (standard) | 100 V or 100/√3 V (line-to-ground) |
| Accuracy classes | 0.2 and/or 0.5 |
| Rated output | 25 VA (0.2 class) / 50 VA (0.5 class) |
| Maximum output | 600 VA (continuous) |
| Insulation level | 50 kV |
| Operating temperature | −25 °C to +40 °C |
| Installation environment | Outdoor |
| Applicable standards | IEC 186; GB 1207-2006 |
| Model variants | JDZW-20 (single secondary) / JDZW2-20 (dual secondary) |
Model Designation
- J: Voltage transformer (VT)
- D: Single-phase
- Z: Cast-resin (epoxy) insulated structure
- W: Outdoor application (weather-resistant)
- 20: Voltage class (kV)
- 2 (in JDZW2): Dual secondary windings with residual voltage output for ground fault detection
Construction
The JDZW-20 and JDZW2-20 feature an outdoor post-type design with fully enclosed epoxy resin cast insulation. This construction provides excellent resistance to moisture, UV radiation, contamination, and thermal aging, ensuring long-term reliability in harsh outdoor environments. The housing meets IP-rated weatherproof requirements and maintains adequate electrical clearance and creepage distances without needing additional enclosures. The laminated magnetic core is optimized for precise voltage transformation, while the integrated primary and secondary insulation system guarantees galvanic isolation under continuous outdoor exposure.
Technical Parameters
Service Conditions
- Installation environment: Outdoor installation (weather-resistant epoxy resin construction)
- Altitude: Not exceeding 1000 m above sea level (higher altitude shall be specified for engineering confirmation)
- Ambient temperature: −25 °C to +40 °C
- Daily average temperature: Not exceeding +30 °C
- Relative humidity: Up to 85% (outdoor environment)
- Environmental conditions: Free from severe industrial pollution or corrosive gases that may affect insulation performance; no explosive or flammable media; designed to withstand outdoor climatic conditions including rain, snow, and UV exposure
Technical Parameters
The JDZW-20 and JDZW2-20 are outdoor cast-resin voltage transformers rated for 20 kV class AC systems (50 Hz / 60 Hz), featuring weather-resistant epoxy resin insulation. They operate within an ambient temperature range of −25 °C to +40 °C and are suitable for installations up to 1000 m altitude. These units comply with standard accuracy classes for metering and protection applications.
Voltage Transformer Data
| Model | Rated Voltage Ratio (V) |
Rated Output (VA) |
Rated Output (VA) |
Maximum Output (VA) |
Rated Insulation Level (kV) |
|---|---|---|---|---|---|
| 0.2 Class | 0.5 Class | ||||
| JDZW-20 | 20000/√3 / 100/√3 | 25 | 50 | 600 | 50 |
| JDZW2-20 | 20000/√3 / 100/√3 / 100/3 | 25 | 50 | 600 | 50 |
Installation & Wiring
Outline Dimensions
The outline dimensions and mounting details for the JDZW-20 and JDZW2-20KV outdoor epoxy resin voltage transformers are shown in the dimensional drawing above. Specific variant dimensions may vary; consult the factory for detailed drawings corresponding to your model.
Wiring Diagram
Selection & FAQs
Selection Guide
- Confirm system voltage class (20 kV) and grounding type (grounded, ungrounded, or impedance-grounded) to determine suitability.
- Choose JDZW-20 for standard voltage measurement or JDZW2-20 if ground fault detection via broken delta connection is required.
- Select accuracy class based on application: 0.2 for revenue metering, 0.5 for general measurement and protection functions.
- Specify rated output (VA) per accuracy class to ensure it supports connected meters, relays, and wiring losses without exceeding burden limits.
- Define connection configuration—Y, V, or broken delta—according to system design and monitoring requirements.
- Include any project-specific needs such as special insulation levels, terminal arrangements, mounting details, or certification requirements during ordering.
Frequently Asked Questions
Q1: Can this 20kV voltage transformer be installed at 1500m altitude?
Standard models are rated for altitudes not exceeding 1000m. For installations at 1500m, please specify the exact altitude during inquiry for engineering derating confirmation.
Q2: Which accuracy class is recommended for protection relays?
Select the 3P or 6P accuracy class for protection applications. These classes ensure reliable performance during fault conditions. Contact us to confirm the exact burden requirements for your specific relay setup.
Q3: What are the ambient temperature limits for outdoor operation?
The JDZW-20 operates safely in ambient temperatures ranging from −25 °C to +40 °C. The daily average temperature must not exceed +30 °C. Verify local climate data matches these conditions before ordering.
Q4: How to customize the rated voltage ratio for specific needs?
Custom voltage ratios are available subject to factory engineering review. Provide your exact primary and secondary voltage requirements in the RFQ. Our technical team will confirm feasibility and lead time.
Q5: Are specific type test certificates available for this model?
Type test reports and compliance certificates are available upon request. Specific test documentation depends on the target market standards. Please specify your required certification standards during the inquiry phase.
Q6: When should this 20kV outdoor voltage transformer be selected?
This unit is ideal for 20kV class AC power systems requiring outdoor voltage measurement. It supports standard metering and protective relaying applications at 50Hz or 60Hz. Confirm system frequency with our sales team before purchasing.
Q7: Why choose epoxy resin insulation for outdoor voltage transformers?
Weather-resistant epoxy resin provides excellent UV, moisture, and pollution resistance. It ensures long-term insulation performance in harsh outdoor environments. Ensure the installation site is free from severe corrosive gases.