Overview
The JSZV series (JSZV1-10R, JSZV2-10R, JSZV3-10R) voltage transformers are precision electromagnetic devices engineered for accurate voltage measurement, energy metering, and relay protection in 3-12 kV indoor AC power systems. Featuring epoxy resin cast insulation and integrated high-voltage fuse protection, these units deliver galvanically isolated secondary signals proportional to the primary voltage, ensuring reliable operation with meters and protective relays.
Built for medium-voltage switchgear environments, the JSZV series combines compact design with robust electrical performance, offering excellent moisture resistance, mechanical strength, and long-term stability under normal indoor operating conditions.
Key Ratings Snapshot
| Parameter | Specification |
|---|---|
| System voltage class | 3 kV / 6 kV / 10 kV |
| Rated frequency | 50 Hz (60 Hz available upon request) |
| Rated secondary voltage | 100 V, 110 V, or 220 V (line-to-neutral) |
| Accuracy classes | 0.2, 0.5 (metering); 3P (protection) |
| Rated output (burden) | 75 VA, 120 VA per winding (as specified) |
| Insulation level | 12/42/75 kV (Um/AC/LI withstand) |
| Integrated HV fuse | XRNPâ¡-12, 0.2 A, 50 kA breaking capacity |
| Highest system voltage (Um) | 12 kV |
| Primary connection | Line-to-ground |
| Phase configuration | Single-phase, V-V, or three-phase |
Model Designation
- J: Voltage transformer (VT / PT)
- S: Three-phase configuration
- Z: Cast-resin (epoxy) insulated, fully enclosed structure
- V: V-V connection type (where applicable)
- 1/2/3: Phase configuration code: 1 = single-phase; 2 = two-element; 3 = three-phase
- 10: Voltage class (kV)
- R: Integrated fuse protection (with HV fuse)
Construction
The JSZV series features a fully enclosed epoxy resin cast design optimized for indoor switchgear applications. The vacuum-cast insulation system ensures superior dielectric strength, moisture resistance, and long-term aging stability. A high-permeability silicon steel core enables precise voltage transformation with minimal losses, while the integrated primary-side HV fuse (XRNPâ¡-12) enhances operational safety and simplifies maintenance.
Mechanical robustness is achieved through monolithic casting, which maintains consistent creepage and clearance distances even in humid or polluted indoor environments. The compact footprint allows space-efficient installation without compromising electrical performance or thermal management.
Technical Parameters
Service Conditions
- Installation environment: Indoor only
- Altitude: <= 1000 m (higher on request)
- Ambient temperature: -5 deg C to +40 deg C
- Relative humidity: <= 95%, non-condensing
- Pollution degree: II
- Mounting orientation: Vertical
- Environmental conditions: Free from corrosive gases, explosive media, severe vibration, or mechanical shock
Technical Data
| Parameter (Selection Reference) |
Specification |
|---|---|
| Rated primary voltage | 3 kV, 6 kV, 10 kV (line-to-ground: 10/√3 kV) |
| Rated secondary voltage | 100 V, 110 V, 220 V (or 100/√3 V, 110/√3 V) |
| Typical voltage ratio | 10000/√3 : 100/√3 : 100/√3 |
| Rated frequency | 50 Hz (60 Hz upon request) |
| Accuracy class (metering) | 0.2, 0.5 |
| Accuracy class (protection) | 3P |
| Rated output (burden) | 75 VA, 120 VA per winding (as specified) |
Installation & Wiring
Installation Diagram
Proper installation requires adherence to polarity markings and grounding standards. Primary terminals (A/X) connect to the medium-voltage bus, while secondary terminals (a/x) feed metering or protection circuits. One point of the secondary circuit must be reliably grounded per IEC/GB requirements. Ensure all circuits are de-energized before handling.
Outline Dimensions
| Dimension | Value (mm) |
|---|---|
| Height | As per dimensional drawing |
| Width | As per dimensional drawing |
| Depth | As per dimensional drawing |
| Mounting hole pattern | As per dimensional drawing |
| Clearance to adjacent parts | Per switchgear specification |
Selection & FAQs
Selection Guide
- Determine system voltage class (3 kV, 6 kV, or 10 kV) to set primary rating.
- Choose phase configuration: JSZV1-10R (single-phase), JSZV2-10R (V-V), or JSZV3-10R (three-phase).
- Select secondary voltage (100 V, 110 V, or 220 V) based on connected instrument requirements.
- Assign accuracy class per application: 0.2/0.5 for metering, 3P for protection.
- Calculate total burden (VA) for each winding including wiring losses; do not exceed rated output.
Frequently Asked Questions
Q1: Can this epoxy resin voltage transformer operate in high humidity?
Yes, it supports relative humidity up to 95% non-condensing. Ensure installation environments remain free from condensation and corrosive gases. Contact engineering for specific site assessments.
Q2: What are the altitude and temperature limits for this 10kV VT?
Standard models support altitudes up to 1000m and ambient temperatures from -5°C to +40°C. Higher altitude requirements are available upon request. Specify your exact site conditions during inquiry.
Q3: Which accuracy class is suitable for protection relays?
Select the 3P accuracy class for protection applications. This class provides the necessary error limits for reliable relay operations. Confirm your specific burden requirements with our technical team.
Q4: Can the rated frequency be customized for 60 Hz power grids?
Yes, 60 Hz configurations are available upon request alongside the standard 50 Hz models. Please specify your grid frequency in the initial RFQ. Our sales team will confirm lead times.
Q5: Are secondary voltages other than 100V available for this transformer?
Yes, standard secondary options include 100V, 110V, 220V, and their √3 variants. Specify your exact secondary voltage and rated burden (75 VA or 120 VA) during ordering.
Q6: What type of switchgear is this epoxy resin VT designed for?
It is designed for 10kV indoor switchgear and power distribution panels. The unit requires vertical mounting and pollution degree II conditions. Verify panel dimensions with our application engineers.