Product Overview
JSZJK-3/6/10R is an indoor three-phase anti-ferroresonance voltage transformer with fuse, using epoxy cast-resin insulation for medium-voltage switchgear applications. It is designed for 50Hz / 60Hz power systems and is used for voltage measurement, energy metering, voltage monitoring, residual-voltage detection and relay protection.
This model is different from ordinary single-phase fused VTs such as JDZ8 or JDZ10. JSZJK-3/6/10R is a three-phase integrated anti-ferroresonance VT, with a larger body, multiple secondary configurations and wiring arrangements suitable for protection schemes requiring anti-ferroresonance and residual-voltage functions.
Product Display
Application Position
The JSZJK-3/6/10R transformer is normally installed inside indoor medium-voltage switchgear or voltage transformer compartments. It supplies secondary voltage to meters, relays and monitoring devices, while its anti-ferroresonance structure helps improve system stability in medium-voltage networks where ferroresonance risk needs to be controlled.
Main Applications
- Indoor 3kV, 6kV and 10kV medium-voltage switchgear
- 3.6kV, 7.2kV and 12kV class power distribution systems
- Voltage measurement and energy metering circuits
- Relay protection voltage input circuits
- Residual-voltage monitoring and insulation supervision circuits
- Switchgear applications requiring a three-phase integrated anti-ferroresonance VT
Key Specifications
| Item | Specification |
|---|---|
| Model series | JSZJK-3R / JSZJK-6R / JSZJK-10R |
| Product type | Indoor three-phase anti-ferroresonance voltage transformer / potential transformer |
| Insulation structure | Indoor epoxy cast-resin insulation |
| Primary protection | With fuse |
| Installation | Indoor switchgear installation |
| System voltage | 3kV, 6kV and 10kV systems |
| International voltage class | 3.6kV, 7.2kV and 12kV classes |
| Rated frequency | 50Hz / 60Hz |
| Ambient temperature | -25°C to +40°C |
| Typical wiring | Single-secondary or dual-secondary configurations with residual-voltage output options |
| Typical function | Metering, voltage monitoring, relay protection and anti-ferroresonance operation |
| Approximate weight | 102kg |
| Standards | GB20840.3-2013, IEC61869-3:2011 and project-specific requirements |
Application Fit
Suitable For
- Indoor switchgear requiring three-phase integrated VT construction
- Medium-voltage systems where ferroresonance suppression is a design concern
- Projects requiring residual-voltage monitoring or protection-related secondary output
- Metering and relay protection applications in 3kV, 6kV and 10kV systems
- Switchgear manufacturers that prefer one integrated three-phase unit instead of three separate single-phase VTs
Not Recommended For
- Outdoor exposed installation without a protective enclosure
- Compact switchgear where a 102kg integrated VT body cannot be accommodated
- Applications that only need a simple single-phase metering VT
- High-frequency electronic transformer applications
- Oil-immersed voltage transformer applications
- Projects requiring non-standard output combinations without technical confirmation
Installation Conditions
- Installation location: indoor switchgear or protected indoor electrical cabinet
- Rated frequency: 50Hz / 60Hz power-frequency AC system
- Ambient temperature: -25°C to +40°C
- Installation space: confirm width, depth, height and 102kg weight before cabinet approval
- Electrical clearance: confirm phase-to-phase and phase-to-ground clearance according to the switchgear design
- Maintenance: inspect fuse condition, secondary terminal fastening and resin surface condition during routine checks
Technical Structure
The JSZJK-3/6/10R series combines three-phase voltage transformation and anti-ferroresonance design in one integrated epoxy cast-resin body. The product is suitable for engineers who require a single three-phase VT solution instead of assembling separate single-phase transformers.
| Component | Description |
|---|---|
| Three-phase magnetic structure | Integrated three-phase transformer structure for metering and protection circuits |
| Anti-ferroresonance design | Designed to reduce ferroresonance risk in medium-voltage systems |
| Primary fuse | Provides primary-side protection according to the selected configuration |
| Epoxy cast-resin body | Provides indoor insulation, mechanical support and moisture resistance |
| Secondary windings | Available with metering, protection and residual-voltage secondary output combinations |
| Terminal section | Multiple secondary terminals arranged for metering and protection wiring |
| Mounting base | Large base structure for stable switchgear installation |
Model Designation
- J = Voltage transformer
- S = Three-phase structure
- Z = Epoxy cast-resin insulation
- J = Anti-ferroresonance / special design series code
- K = Structure or design code, subject to final drawing
- 3 / 6 / 10 = Rated system voltage code for 3kV, 6kV or 10kV applications
- R = With fuse
Technical Data
The following data is organized from the JSZJK-3/6/10R product sample. For international product pages, the domestic 3kV / 6kV / 10kV system ratings should be matched with 3.6kV / 7.2kV / 12kV insulation classes.
| Model | Rated
Voltage Ratio |
Accuracy Class /
Rated Output |
Limit
Output |
Rated
Insulation Level |
|---|---|---|---|---|
| JSZJK-3R | 3000/√3 / 100/√3 / 100 | 0.2/6P(3P)—45/100 0.5/6P(3P)—100/100 1/6P(3P)—150/100 |
600VA | 3.6/25/40kV |
| JSZJK-6R | 6000/√3 / 100/√3 / 100 | 7.2/30/60kV | ||
| JSZJK-10R | 10000/√3 / 100/√3 / 100 | 12/42/75kV | ||
| JSZJK-6R | 6000/√3 / 100/√3 / 100/√3 / 100 | 0.2/0.2/6P(3P)—30/30/100 0.2/0.5/6P(3P)—30/50/100 0.5/0.5/6P(3P)—50/50/100 |
500VA | 7.2/30/60kV |
| JSZJK-10R | 10000/√3 / 100/√3 / 100/√3 / 100 | 0.2/0.2/6P(3P)—30/30/100 0.2/0.5/6P(3P)—30/50/100 0.5/0.5/6P(3P)—50/50/100 |
500VA | 12/42/75kV |
| JSZJK-6R | 6000/√3 / 100/√3 / 220/√3 / 100 | 0.2/3/6P(3P)—30/500/100 0.5/3/6P(3P)—50/500/100 |
600VA | 7.2/30/60kV |
| JSZJK-10R | 10000/√3 / 100/√3 / 220/√3 / 100 | 0.2/3/6P(3P)—30/500/100 0.5/3/6P(3P)—50/500/100 |
600VA | 12/42/75kV |
Technical notes:
- One transformer is supplied with one selected accuracy class and rated output combination.
- The 100/√3 output is commonly used for metering or voltage monitoring.
- The 220/√3 output can be selected when auxiliary power or special secondary output is required.
- The 100V residual or open-delta output can be used for protection-related monitoring according to project design.
- If the required parameters exceed the listed range, confirmation between manufacturer and purchaser is required.
Installation and Dimensions
Dimension Reference
| Item | Reference Value |
|---|---|
| Overall length | 490mm reference |
| Base length | 455mm reference |
| Side length reference | 430mm |
| Body length reference | 370mm |
| Overall width | 425mm reference |
| Body width reference | 190mm |
| Overall height | Approx. 298mm reference |
| Primary terminal spacing | 210mm + 210mm reference |
| Approximate weight | 102kg |
Terminal and Wiring
- Primary terminals are arranged for A, B and C phases.
- Secondary terminals may include 1a, 1b, 1c, 2a, 2b, 2c and da terminals depending on configuration.
- The sample drawing shows one-secondary and two-secondary winding arrangements.
- For residual-voltage protection, confirm the open-delta / da terminal configuration before wiring.
- Terminal polarity, grounding and fuse condition must be verified before commissioning.
Compliance and Testing
The product information references GB20840.3-2013 and IEC61869-3:2011. Additional sample information also refers to GB1207 and IEC60044-2. For export projects, the final compliance statement should follow the technical agreement and buyer specification.
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
- Induced withstand voltage test where applicable
- Insulation resistance test
- Fuse and primary circuit inspection
- Residual-voltage winding verification when supplied
Engineering Notes
- Use JSZJK-3R for 3kV systems, JSZJK-6R for 6kV systems and JSZJK-10R for 10kV systems.
- For international pages, write the models as 3.6kV, 7.2kV and 12kV class products according to insulation level.
- Choose this series when anti-ferroresonance performance is required, not only basic voltage measurement.
- Confirm whether the project requires one secondary winding, two secondary windings or residual-voltage output.
- The approximate 102kg weight should be checked carefully during switchgear layout design.
- Do not describe this product as a high-frequency transformer; it is a 50Hz / 60Hz power-frequency VT/PT.
Selection Guide
Select by ferroresonance requirement: Choose JSZJK-3/6/10R when the switchgear project needs a three-phase anti-ferroresonance VT rather than a simple single-phase fused voltage transformer.
Select by voltage class: Use JSZJK-3R for 3kV systems, JSZJK-6R for 6kV systems and JSZJK-10R for 10kV systems. For international specifications, express them as 3.6kV, 7.2kV and 12kV classes.
Select by secondary configuration: Use the basic 100/√3 and 100 outputs for metering and protection. Choose dual-secondary or 220/√3 output versions when auxiliary output or separated circuits are required.
Select by protection scheme: If the system requires residual-voltage detection, insulation monitoring or open-delta output, confirm the da terminal and residual winding arrangement before production.
Select by cabinet layout: Confirm the 102kg weight, 490mm overall length, terminal spacing and secondary terminal access before approving the switchgear design.