Overview
The JDZ9-35 and JDZF9-35 outdoor epoxy resin cast voltage transformers are precision electromagnetic instruments engineered for accurate voltage measurement, energy metering, system monitoring, and relay protection in 35kV medium-voltage AC outdoor power networks. These devices operate on electromagnetic induction principles to deliver galvanically isolated secondary voltage signals proportional to the primary system voltage, ensuring safety and signal fidelity.
Built for reliability in harsh environments, the JDZ9-35/JDZF9-35 series features fully enclosed epoxy resin insulation that provides excellent resistance to UV radiation, moisture, pollution, and mechanical stress. This robust construction enables long-term, maintenance-free operation in standard outdoor substation installations without the risks associated with oil-filled alternatives.
Key Ratings Snapshot
| Item | Specification |
|---|---|
| System voltage class | 35 kV (outdoor medium-voltage) |
| Rated frequency | 50 Hz (60 Hz available on request) |
| Rated primary voltage | 35000 V (line-to-ground) |
| Rated secondary voltage | 100 V or 220 V (line-to-ground); 100/â3 V for wye systems |
| Accuracy classes | 0.2, 0.5 (metering); 6P (protection) |
| Rated burden | 20â90 VA per winding |
| Burden power factor | cosÏ = 0.8 (lagging) |
| Maximum output capacity | 300â800 VA (model dependent) |
| Insulation level | 40.5 / 95 / 200 kV (Um / LIWL / ACWL) |
| Applicable standards | IEC 61869-3; GB/T 20840.3; GB 1207-2006 |
Model Designation
- J: Voltage transformer (VT)
- D: Single-phase configuration
- Z: Cast-resin (epoxy) insulated, fully enclosed
- F: Dual secondary windings (when present)
- 9: Design code (platform iteration)
- 35: Voltage class in kV
Construction
The JDZ9-35 and JDZF9-35 feature an outdoor post-type design with bottom flange mounting for secure substation installation. The core is constructed from high-grade silicon steel laminations optimized for low magnetic flux density operation, ensuring linearity and accuracy across the rated voltage range. Primary and secondary windings are fully encapsulated in UV-stable epoxy resin, forming a monolithic, void-free structure that resists tracking, aging, and environmental degradation.
This integrated insulation system maintains consistent dielectric performance under varying humidity, temperature, and pollution conditions. The design complies with II-grade pollution requirements and includes sufficient creepage and clearance distances for reliable outdoor service. Optional integration of zinc oxide lightning arresters enhances surge protection where required by system studies.
Technical Parameters
Service Conditions
- Installation environment: Outdoor, post-mounted in substations
- Altitude: <= 1000 m above sea level
- Ambient temperature: -25 deg C to +40 deg C (daily average <= 30 deg C)
- Relative humidity: Daily average <= 95%, monthly average <= 90%
- Pollution grade: Grade II
- Environmental conditions: No corrosive gases, explosive media, or abnormal vibration
Technical Data
| Model | Rated Voltage Ratio (V) |
Accuracy Class Combination |
Rated Output (VA) |
Maximum Output (VA) |
Insulation Level (kV) Um / LIWL / ACWL |
|---|---|---|---|---|---|
| JDZ9-35 | 35000 / 100 35000 / 220 |
0.2 | 50 | 800 | 40.5 / 95 / 200 |
| JDZ9-35 | 35000 / 100 35000 / 220 |
0.5 | 90 | 800 | 40.5 / 95 / 200 |
| JDZF9-35 | 35000 / 100 / 100 35000 / 100 / 220 |
0.2 / 0.2 | 30/30, 30/50, 50/50 | 2 x 400 | 40.5 / 95 / 200 |
| JDZF9-35 | 35000 / 100 / 100 35000 / 100 / 220 |
0.2 / 0.5 | 30/30, 30/50, 50/50 | 2 x 400 | 40.5 / 95 / 200 |
| JDZF9-35 | 35000 / 100 / 100 35000 / 100 / 220 |
0.5 / 0.5 | 30/30, 30/50, 50/50 | 2 x 400 | 40.5 / 95 / 200 |
Installation & Wiring
Installation Diagram
Primary connection is made via high-voltage busbar or terminal connector at terminal A. Terminal X must be grounded per system grounding practice. Secondary terminals must be connected to meters, relays, or monitoring equipment with one point (typically x or x1) reliably grounded. Adequate phase-to-phase and phase-to-ground clearances must be maintained for insulation coordination and safety.
Outline Dimensions
| Dimension | Value (mm) |
|---|---|
| Total height | Approx. 650 |
| Base flange width | Approx. 200 |
| Mounting hole pattern | 4 x phi14, PCD approx. 160 |
| Phase-to-ground clearance | >= 300 |
| Phase-to-phase clearance | >= 500 |
Selection & FAQs
Selection Guide
- Specify primary voltage as 35000 V (line-to-ground) for ungrounded systems or 35kV/â3 for grounded wye systems.
- Select secondary voltage (100 V, 220 V, or 100/â3 V) based on connected instrument requirements and system configuration.
- Choose JDZ9-35 for single-purpose applications; select JDZF9-35 for separate metering and protection circuits.
- Ensure rated burden (VA) exceeds total connected load (instruments + wiring) by 20-30% margin for accuracy and thermal safety.
- Confirm accuracy class: 0.2 or 0.5 for revenue metering; 6P only if protection function is needed (not applicable to base JDZ9-35).
- For altitudes > 1000 m or pollution grade > II, request engineering review for insulation coordination.
Frequently Asked Questions
Q1: What are the environmental limits for outdoor installation?
Designed for outdoor post-mounting up to 1000m altitude. Ambient temperature must remain between -25°C and +40°C with Grade II pollution. Confirm specific site conditions with our engineering team.
Q2: Which accuracy class is available for the JDZF9-35 model?
The JDZF9-35 offers 0.2/0.2 or 0.2/0.5 accuracy class combinations. Rated outputs range from 30/30 VA to 50/50 VA depending on your selection. Specify your required burden during inquiry.
Q3: What is the insulation level for these 35kV transformers?
Both models feature a 40.5 kV highest equipment voltage, 95 kV LIWL, and 200 kV ACWL. Epoxy resin casting ensures reliable insulation. Contact us for specific test reports.
Q4: Can you provide third-party testing certificates for these transformers?
Standard factory tests are included, while third-party certifications are subject to confirmation. Please specify your required testing standards and certificate types during the procurement phase.
Q5: How long is the delivery time for custom voltage ratios?
Lead times for custom ratios like 35000/220V are subject to confirmation based on current production schedules. Contact our sales team with your exact quantity and specifications.
Q6: Where are these epoxy resin voltage transformers typically applied?
They are primarily used in outdoor substations for voltage measurement and protection in 35kV systems. Ensure the installation site is free from corrosive gases and abnormal vibration.
Q7: Are these cast resin transformers suitable for high-humidity areas?
Yes, the epoxy resin casting withstands daily average relative humidity up to 95% and monthly averages up to 90%. Verify your specific microclimate conditions with our technical support.