Product Overview
The JSZGF-3/6/10R fused three-phase anti-ferroresonance voltage transformer is an indoor epoxy cast-resin voltage transformer designed for 3.6kV, 7.2kV and 12kV medium-voltage switchgear. It converts three-phase primary voltage into secondary voltage signals for metering, monitoring, residual-voltage detection and relay protection.
This series combines an anti-ferroresonance voltage transformer structure with integrated primary fuse protection. It is suitable for medium-voltage systems where voltage transformer resonance, grounding fault monitoring and primary-side protection must be considered in the switchgear design.
Application Position
The JSZGF-3/6/10R voltage transformer is normally installed in the voltage transformer compartment of indoor medium-voltage switchgear. It provides secondary voltage signals to metering instruments, protection relays, grounding fault monitoring devices and control equipment.
Main Applications
- 3.6kV, 7.2kV and 12kV indoor medium-voltage switchgear
- Three-phase voltage metering and voltage indication circuits
- Residual-voltage and grounding fault detection circuits
- Relay protection voltage input circuits
- Power monitoring and energy metering systems
- Switchgear applications requiring fused anti-ferroresonance voltage transformer design
Key Specifications
| Item | Specification |
|---|---|
| Model series | JSZGF-3R / JSZGF-6R / JSZGF-10R |
| Product type | Fused three-phase anti-ferroresonance voltage transformer |
| Insulation structure | Indoor epoxy cast-resin insulation |
| Installation | Indoor switchgear installation |
| Rated voltage class | 3.6kV, 7.2kV and 12kV |
| Rated frequency | 50Hz or 60Hz |
| Ambient temperature | -25°C to +40°C |
| Primary protection | Integrated fuse structure |
| Secondary winding configuration | Metering, residual-voltage and protection secondary options according to model |
| Accuracy class | 0.2, 0.5, 1, 3P, 6P and combined metering/protection configurations |
| Limit output | 500VA |
| Standards | GB20840.3-2013, IEC61869-3:2011 and project-specific requirements |
Application Fit
Suitable For
- Indoor 3.6kV, 7.2kV and 12kV medium-voltage switchgear
- Voltage transformer compartments requiring integrated fuse protection
- Metering and monitoring circuits requiring stable three-phase voltage signals
- Residual-voltage and grounding fault detection systems
- Relay protection circuits requiring anti-ferroresonance VT design
Not Recommended For
- Outdoor exposed installation without a suitable enclosure
- Low-voltage systems outside the medium-voltage design range
- Applications requiring oil-immersed voltage transformer construction
- Special fuse ratings, voltage ratios or secondary winding arrangements without technical confirmation
Model Comparison
| Model | Voltage Class | Typical Use | Selection Note |
|---|---|---|---|
| JSZGF-3R | 3.6kV | Three-phase metering and residual-voltage protection | Select for 3.6kV switchgear with 3.6/25/40kV insulation level |
| JSZGF-6R | 7.2kV | 7.2kV switchgear voltage monitoring and protection | Select according to secondary winding configuration and fuse requirement |
| JSZGF-10R | 12kV | 12kV switchgear metering, monitoring and relay protection | Select according to 12/42/75kV insulation level and secondary output requirement |
Technical Structure
| Component | Description |
|---|---|
| Three-phase core and winding system | Provides three-phase voltage transformation and secondary signal output |
| Anti-ferroresonance structure | Designed to reduce the risk of ferroresonance under applicable operating conditions |
| Primary fuse | Integrated fuse structure for primary-side protection in switchgear applications |
| Epoxy cast-resin insulation | Indoor dry-type insulation structure for medium-voltage equipment |
| Secondary terminal groups | Terminal groups for metering, residual-voltage and protection circuits |
| Mounting base | Base-mounted structure for indoor switchgear installation |
Model Designation
The JSZGF-R model code can be interpreted as follows:
| Code | Meaning |
|---|---|
| J | Voltage transformer |
| S | Three-phase structure |
| Z | Epoxy cast-resin insulation |
| G / F | Anti-ferroresonance / product structure code |
| 3 / 6 / 10 | Model voltage code corresponding to 3.6kV, 7.2kV and 12kV classes |
| R | Fuse-equipped structure / product variant code |
Technical Data
The following technical data is based on the JSZGF-3R, JSZGF-6R and JSZGF-10R product sample. The page uses international medium-voltage class expression for export applications. Voltage ratio values are retained according to the actual primary and secondary winding ratings.
General Technical Conditions
| Item | Technical Condition |
|---|---|
| Load power factor | cosφ = 0.8, lagging |
| Surface creepage distance | Complies with pollution class II requirements |
| Product standards | GB/T 20840.1, GB/T 20840.3, GB20840.3-2013 and IEC61869-3:2011 |
| Rated frequency | 50Hz or 60Hz |
| Ambient temperature | -25°C to +40°C |
Electrical Technical Data
| Type | Voltage
Class |
Voltage
Ratio |
Accuracy Class
and Rated Output |
Limit
Output (VA) |
Rated
Insulation Level (kV) |
|---|---|---|---|---|---|
| JSZGF-3R | 3.6kV | 3000/√3 / 0.1/√3 / 0.1/3 | 0.2/6P(3P)—20/100 0.5/6P(3P)—30/100 1/6P(3P)—100/100 |
500 | 3.6/25/40 |
| JSZGF-6R | 7.2kV | 6000/√3 / 0.1/√3 / 0.1/3 | 0.2/6P(3P)—20/100 0.5/6P(3P)—30/100 1/6P(3P)—100/100 |
7.2/30/60 | |
| JSZGF-10R | 12kV | 10000/√3 / 0.1/√3 / 0.1/3 | 0.2/6P(3P)—20/100 0.5/6P(3P)—30/100 1/6P(3P)—100/100 |
12/42/75 | |
| JSZGF-6R | 7.2kV | 6000/√3 / 0.1/√3 / 0.1/√3 / 0.1/3 | 0.2/0.5/6P(3P)—10/15/100 | 7.2/30/60 | |
| JSZGF-10R | 12kV | 10000/√3 / 0.1/√3 / 0.1/√3 / 0.1/3 | 0.2/0.5/6P(3P)—10/15/100 | 12/42/75 |
Technical notes:
- Rated output and its corresponding accuracy class are supplied as one selected combination only.
- If the required parameters exceed the listed range, they should be confirmed by agreement between manufacturer and purchaser.
- Rated frequency: 50Hz or 60Hz.
- The transformer should be selected according to switchgear voltage class, voltage ratio and secondary winding requirement.
Installation and Dimensions
The JSZGF-3/6/10R series should be installed according to the approved outline drawing, wiring diagram and switchgear layout. The product is a three-phase integrated structure with built-in fuse elements, multiple primary bushings and secondary terminal groups.
Dimension Reference
| Item | Dimension / Specification |
|---|---|
| Overall length | 624 mm |
| Base reference length | 590 mm |
| Phase spacing | 182 mm + 182 mm |
| Overall width | 395 mm |
| Body reference width | 330 mm |
| Overall height | 323 mm |
| Main body height | 293 mm |
| Fuse specification reference | Indoor AC high-voltage fuse, 0.5A, 50kA reference shown in sample drawing |
Terminal and Wiring Notes
- Primary terminals and secondary terminals should be connected according to the approved wiring diagram.
- The sample wiring diagram shows Y/Y/△ connection with four winding groups.
- Residual-voltage and protection secondary circuits should be connected according to the project protection scheme.
- Fuse specification and replacement clearance should be confirmed before switchgear layout approval.
- Terminal markings and grounding arrangement must be verified before commissioning.
Compliance and Testing
The JSZGF-3/6/10R series is designed for indoor medium-voltage voltage transformer applications. The provided product sample refers to GB20840.3-2013 and IEC61869-3:2011, together with customer-specific requirements.
Typical Routine Tests
- Visual inspection and nameplate verification
- Ratio verification
- Polarity and terminal marking check
- Accuracy test at specified rated burden
- Power-frequency withstand voltage test
- Insulation resistance test
- Fuse and primary circuit inspection
- Secondary winding and residual-voltage winding verification
Engineering Notes
- Select JSZGF-3R, JSZGF-6R or JSZGF-10R according to the required 3.6kV, 7.2kV or 12kV switchgear class.
- Confirm the fuse specification, secondary winding configuration and anti-ferroresonance requirement before ordering.
- Do not exceed the rated output corresponding to the selected accuracy class.
- For residual-voltage or grounding fault protection, confirm secondary voltage ratio and protection class.
- Check overall dimensions, fuse clearance and switchgear space before installation.
- For special ratios, special protection classes or environmental conditions, technical confirmation is required.
Selection Guide
How to select the correct JSZGF-R model
Select JSZGF-3R for 3.6kV switchgear, JSZGF-6R for 7.2kV switchgear and JSZGF-10R for 12kV switchgear. The rated insulation level and voltage ratio should match the switchgear rated voltage and protection scheme.
How to confirm fuse requirement
The R type includes a fused structure. Confirm the fuse current rating, breaking capacity, installation clearance and primary circuit protection requirement according to the switchgear design.
How to select secondary winding configuration
Select the secondary winding arrangement according to whether the project requires metering, residual-voltage monitoring, relay protection or separate secondary circuits.
How to select accuracy class and rated output
Use 0.2 or 0.5 accuracy class for metering circuits and 3P or 6P protection classes for residual-voltage or relay protection circuits. The rated output should be higher than the total connected secondary burden.
Ordering Information
Please provide the following information when ordering or requesting a quotation:
- Product model: JSZGF-3R, JSZGF-6R or JSZGF-10R
- Rated voltage ratio and secondary winding configuration
- Rated frequency: 50Hz or 60Hz
- Required accuracy class and rated output
- Fuse rating and breaking capacity requirement
- Residual-voltage or protection winding requirement
- Rated insulation level
- Installation dimensions or switchgear layout requirements
- Applicable standard or project specification
- Quantity
- Special requirements for drawings, test reports, certificates, nameplate language, packaging or shipping