Overview
The JSZV12-20R is a three-phase epoxy resin cast combined voltage transformer with built-in fuse protection, engineered specifically for XGW-12 outdoor AC metal-enclosed switchgear in 12-20 kV distribution systems. It delivers dual secondary outputs: 100V for precision metering and 220V for reliable auxiliary power supply to circuit breaker control and protection circuits.
Its compact, fully enclosed design integrates measurement and power functions into a single unit, enhancing system efficiency while reducing installation footprint. The V-connection (open-delta) configuration supports accurate voltage monitoring and ground fault detection in medium-voltage networks.
Key Ratings Snapshot
| Parameter | Value |
|---|---|
| System voltage class | 12 kV (rated 20 kV) |
| Rated frequency | 50 Hz |
| Rated primary voltage | 20 kV / sqrt(3) |
| Rated secondary voltage | 100V, 220V |
| Accuracy classes | 0.2, 0.5 |
| Primary connection | V-connection (open-delta) |
| Fuse protection | Built-in primary winding fuse |
| Insulation level (Um/Ud/Up) | 24/65/125 kV |
| Construction | Epoxy resin cast, fully enclosed |
| Standards compliance | GB 1207-1997 |
Model Designation
- J: Voltage transformer (VT)
- S: Three-phase configuration
- Z: Cast-resin (epoxy) insulated structure
- V: V-connection (open-delta) configuration
- 12: Voltage class (kV)
- 20: Rated voltage (kV)
- R: Built-in fuse protection
Construction
The JSZV12-20R features a robust epoxy resin cast construction with a fully enclosed design, ensuring superior insulation performance, high mechanical strength, and excellent resistance to moisture, contamination, and agingâcritical for long-term outdoor switchgear operation. The integrated fuse protection is positioned at the primary output terminals for straightforward access during maintenance or replacement.
This combination unit consolidates voltage measurement and auxiliary power supply into one compact assembly, optimizing space within XGW-12 metal-enclosed switchgear compartments while maintaining galvanic isolation and proportional secondary output accuracy relative to the primary voltage.
Technical Parameters
Service Conditions
- Installation environment: Outdoor metal-enclosed switchgear (XGW-12)
- Altitude: <=1000 m above sea level (pollution level II)
- Ambient temperature: -5 degC to +40 degC
- Relative humidity: <=80%
- Environmental conditions: Free from corrosive gases or vapor; free from carbon dust or conductive metallic dust; no severe vibration or mechanical shock
Technical Data
| Model | Rated Voltage Ratio (V) |
Class 0.2 Output (VA) |
Class 0.5 Output (VA) |
Rated Insulation Level (kV) |
|---|---|---|---|---|
| JSZV12-20R | 20000/100 | 30 | 50 | 24/65/125 |
| JSZV12-20R | 20000/100/100 | 20 | 50 | 24/65/125 |
| JSZV12-20R | 20000/220 | 20 | 50 | 24/65/125 |
| JSZV12-20R | 20000/100/220 | 20 | 50 | 24/65/125 |
Installation & Wiring
Installation Diagram
The JSZV12-20R is designed for secure mounting within the designated compartment of XGW-12 outdoor metal-enclosed switchgear. Primary connections interface directly with integrated busbar terminals, while secondary wiring connects to clearly marked terminals for measurement and auxiliary circuits. Adequate clearance must be maintained around the unit for insulation integrity, heat dissipation, and service access. The built-in fuse is accessible from the front panel for quick replacement without disassembly.
Outline Dimensions
| Dimension | Value (mm) |
|---|---|
| Height | Refer to switchgear documentation |
| Width | Refer to switchgear documentation |
| Depth | Refer to switchgear documentation |
| Mounting hole pattern | As per XGW-12 compartment design |
Selection & FAQs
Selection Guide
- Specify rated voltage ratio (e.g., 20000/100/220) based on local grid requirements
- Select accuracy class (0.2 for revenue metering, 0.5 for general monitoring)
- Confirm rated burden (VA) for each secondary winding to ensure accuracy under actual load
- Verify application need: voltage measurement only, auxiliary power only, or combined function
- Ensure compatibility with XGW-12 switchgear compartment dimensions and terminal layout
- For non-standard environments (e.g., high altitude, extended temperature), request customization
Frequently Asked Questions
Q1: What is the maximum burden for Class 0.2 accuracy?
The Class 0.2 output is rated at 20 to 30 VA depending on the selected voltage ratio. Ensure your connected metering devices do not exceed this limit. Contact our engineering team for detailed burden calculations.
Q2: Can this voltage transformer be installed at high altitudes?
Standard installation is restricted to altitudes of 1000 meters or less above sea level. For higher altitude deployments, derating factors apply. Please consult our technical department for site-specific environmental evaluations.
Q3: Which switchgear models are compatible with this combined transformer?
It is specifically designed for outdoor metal-enclosed switchgear, particularly the XGW-12 model. Integration guidance and dimensional checks are available. Reach out to our application engineers to verify mechanical fitment for your specific enclosure.
Q4: Are custom voltage ratios available for this 20kV model?
Standard ratios include 20000/100, 20000/100/100, 20000/220, and 20000/100/220. Custom ratio configurations are subject to factory confirmation based on your project specifications. Submit your exact requirements to our sales team for feasibility review.
Q5: What factory tests are performed before shipment?
Routine tests verify compliance with the 24/65/125 kV rated insulation level before shipment. Specific test certificates and detailed factory acceptance test reports are available. Contact our quality assurance department to request documentation for your procurement records.
Q6: Why use this combined voltage transformer with fuse?
It integrates voltage transformation and fuse protection into a single compact unit for 20kV outdoor networks. This simplifies switchgear design and reduces installation space. Contact our engineering team for integration guidance.
Q7: Who manufactures this JSZV12-20R voltage transformer?
This equipment is produced by a specialized manufacturer of medium-voltage instrument transformers. We provide comprehensive application engineering support and global distribution. Reach out to our sales department for manufacturer certification details.