Overview
The JDZW-35 and JDZ(X)FW-35 series are outdoor cast-resin voltage transformers designed for 35 kV power distribution systems. These single-phase electromagnetic instruments feature fully enclosed epoxy resin insulation, ensuring reliable operation in harsh outdoor environments with resistance to moisture, UV radiation, and pollution.
Built to meet IEC 61869-3 and GB/T 20840.3 standards, they deliver high accuracy for metering (e.g., class 0.2/0.5) and protection (e.g., 6P) applications. Typical uses include revenue metering, relay protection, SCADA voltage monitoring, and system synchronization in 35 kV substations and outdoor switchgear installations.
Key Ratings Snapshot
| Parameter | Rating |
|---|---|
| System voltage class | 35 kV |
| Rated frequency | 50 Hz (60 Hz optional) |
| Primary voltage | 35000 V or 35000/√3 V |
| Secondary voltage | 100 V; 100/100 V; or 100/√3/100/3 V |
| Accuracy classes | 0.2 / 0.5 (metering), 6P (protection) |
| Rated burden | As specified per winding (VA) |
| Burden power factor | cosφ = 0.8 lagging |
| Rated output capacity | 30–100 VA per winding |
| Maximum output capacity | 400–1000 VA |
| Insulation level | 40.5/95/200 kV (Ur/LI/PF) |
| Applicable standards | IEC 61869-3, GB/T 20840.3, GB 1207-2006 |
Model Designation
- J: Voltage transformer (VT)
- D: Single-phase configuration
- Z: Support (pillar) type mounting
- W: Outdoor service (weather-resistant)
- F: Dual secondary windings
- X: Open delta (residual voltage) winding
- 35: Voltage class in kV
Construction
The transformer features a support-type post design with fully enclosed cast-resin insulation using outdoor-grade epoxy formulated with UV stabilizers and arc-resistant compounds. The core is made of laminated cold-rolled silicon steel, optimized for low losses and stable magnetic performance. Vacuum pressure gelation (VPG) casting technology ensures void-free insulation with uniform dielectric strength, long-term thermal stability, and resistance to environmental aging. Secondary terminals (1a/1n, 2a/2n, da/dn as applicable) are housed in a sealed metal terminal box with protective cover to prevent moisture ingress and unauthorized access, complying with IEC 61869-3 polarity conventions.
Technical Parameters
Service Conditions
- Installation environment: Outdoor installation (weather-resistant construction)
- Altitude: Not exceeding 1000 m above sea level (higher altitude shall be specified for engineering confirmation and derating)
- Ambient temperature: −5 °C to +40 °C
- Daily average temperature: ≤ 30 °C
- Relative humidity: Daily average ≤ 95%, monthly average ≤ 90% (at +20 °C reference)
- Pollution severity: Class II or lower per IEC 60815
- Environmental conditions: Free from corrosive gases, explosive atmospheres, or severe mechanical shock
- Seismic conditions: Seismic intensity ≤ 8 per applicable regional standard
Technical Parameters
The JDZW-35 series are outdoor cast-resin voltage transformers rated for 35 kV class AC systems (50 Hz standard, 60 Hz available). They feature weather-resistant construction, operate within an ambient temperature range of −5 °C to +40 °C, and are suitable for altitudes up to 1000 m. The design complies with IEC standards for insulation coordination and accuracy performance.
Voltage Transformer Data
| Type (Ratio) |
Accuracy Class Combination |
Rated Output (VA) |
Maximum Output per Winding (VA) |
Rated Insulation Level (kV) |
|---|---|---|---|---|
| JDZW-35 35000/100 |
0.2 | 75 | 1000 | 40.5/95/200 |
| 0.5 | 100 | 1000 | ||
| JDZFW-35 35000/100/100 |
0.2/0.2 | 30/30 | 2 × 500 | |
| 0.2/0.5 | 30/60 | 2 × 500 | ||
| 0.5/0.5 | 60/60 | 2 × 500 | ||
| JDZXW-35 35000/√3/100/√3/100/3 |
0.2/6P | 40/100 | 1000 | |
| 0.5/6P | 80/100 | 1000 | ||
| 0.2/0.2/6P | 20/20/100 | 1000 | ||
| JDZXFW-35 35000/√3/100/√3/100/3/100/3 |
0.2/0.5/6P | 25/25/100 | 2 × 400 | |
| 0.5/0.5/6P | 40/40/100 | 2 × 400 |
Installation & Wiring
Outline Dimensions
The outline dimensions and mounting details for the JDZW-35 and JDZ(X)FW-35kV outdoor cast-resin voltage transformers are shown in the drawing above. Ensure adequate space is provided for installation, maintenance access, heat dissipation, and compliance with insulation coordination requirements.
Wiring Diagram
The wiring diagram illustrates the internal connections and terminal markings for the secondary windings. Primary connection is made via high-voltage terminals at the top of the unit, while secondary wiring is accessible through the sealed terminal box. Secondary circuits must be connected according to the specified terminal designations and grounded at a single point as required by IEC 61869-1 and local regulations.
Selection & FAQs
Selection Guide
- Determine primary voltage configuration based on system voltage (35 kV line-to-line) and grounding arrangement (grounded or isolated neutral).
- Select the appropriate model: JDZW-35 for single secondary, JDZFW-35 for dual secondary, JDZXW-35/JDZXFW-35 for residual voltage detection with triple or quad secondaries.
- Specify metering and/or protection accuracy classes (e.g., 0.2 / 0.5 for metering; 6P for protection) per application needs.
- Confirm rated burden (VA) for each secondary winding to cover connected meters, relays, and wiring losses with a 20-30% margin.
- Verify insulation level (standard 40.5/95/200 kV) aligns with system requirements per IEC 60071-1.
- Declare special conditions at ordering stage if altitude exceeds 1000 m, pollution severity exceeds Class II, or other project-specific requirements apply.
Frequently Asked Questions
Q1: Can this 35kV outdoor voltage transformer be installed above 1000m altitude?
Standard models are rated for altitudes up to 1000 meters. For higher elevations, derating applies and engineering confirmation is required. Contact our technical team for specific high-altitude specifications.
Q2: Which accuracy class combinations are available for the JDZW-35 series?
Multiple accuracy class combinations are available depending on your specific ratio and output requirements. Refer to the technical parameter table for exact rated and maximum output per winding. Specify your metering and protection needs for factory selection.
Q3: What environmental conditions must be avoided during outdoor installation?
The transformer must be installed in environments free from corrosive gases, explosive atmospheres, and severe mechanical shock. Pollution severity should be Class II or lower per IEC 60815. Verify site conditions before installation.
Q4: Are 60Hz configurations available for the JDZ(X)FW-35KV transformers?
Yes, while 50Hz is the standard frequency, 60Hz configurations are available upon request. The internal design is adjusted to maintain accuracy at the higher frequency. Specify your system frequency during the initial inquiry for factory customization.
Q5: Which IEC standards does this cast-resin voltage transformer comply with?
The design complies with relevant IEC standards for insulation coordination and accuracy performance. Standard factory routine tests are performed prior to shipment. Request the specific test certificate and compliance documentation for your project.
Q6: How is the JDZW-35 series applied in AC power systems?
These outdoor cast-resin voltage transformers are designed for 35kV class AC power systems. They provide accurate voltage measurement and protection signals for outdoor switchgear and substations. Confirm your primary application with our sales team.
Q7: What is the maximum seismic intensity rating for this equipment?
The equipment is designed to withstand seismic intensities up to 8 according to applicable regional standards. For installations in highly active seismic zones, specialized mounting solutions may be required. Contact engineering for site-specific assessments.