Overview
The JSZJK-3/6/10R is an indoor three-phase anti-ferroresonance voltage transformer with integrated primary fuses, designed for 3kV, 6kV, and 10kV medium-voltage systems (corresponding to 3.6kV, 7.2kV, and 12kV insulation classes). It features epoxy cast-resin insulation, making it suitable for installation within indoor switchgear compartments.
This transformer supports voltage measurement, energy metering, relay protection, and residual-voltage monitoring in 50Hz or 60Hz power systems. Its anti-ferroresonance design enhances stability in networks prone to ferroresonant overvoltages. The product complies with GB20840.3-2013 and IEC61869-3:2011 standards, ensuring reliability in critical protection and metering applications.
Key Ratings Snapshot
| Parameter | Rating |
|---|---|
| System Voltage | 3kV / 6kV / 10kV |
| Insulation Class | 3.6kV / 7.2kV / 12kV |
| Frequency | 50Hz / 60Hz |
| Insulation Type | Epoxy cast-resin |
| Primary Protection | With fuse |
| Phase Configuration | Three-phase integrated |
| Secondary Outputs | Single or dual, with residual-voltage option |
| Ambient Temperature | -25°C to +40°C |
| Application | Metering, protection, monitoring, anti-ferroresonance |
| Installation | Indoor switchgear |
| Weight | Approx. 102kg |
| Standards | GB20840.3-2013, IEC61869-3:2011 |
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
Construction
The JSZJK-3/6/10R features a robust three-phase integrated design with epoxy cast-resin insulation, providing excellent dielectric strength and mechanical durability for indoor medium-voltage environments. The entire assembly is encapsulated in solid resin, eliminating the need for oil or gas insulation and enhancing fire safety. Primary windings are protected by built-in fuses housed within the cast body, while secondary terminals are accessible via a dedicated terminal block. The construction supports multiple secondary configurations, including options for residual-voltage output, enabling flexible integration into protection and monitoring schemes. The unit’s compact yet heavy-duty form factor (approx. 102kg) is engineered for secure mounting inside standard indoor switchgear cabinets.
Technical Parameters
Service Conditions
- Ambient temperature: -5°C to +40°C
- Altitude: ≤1000 m above sea level
- Relative humidity: daily average ≤95%, monthly average ≤90%
- Installation environment: indoor, non-corrosive, free from severe vibration and explosive hazards
Technical Parameters
The JSZJK-3/6/10R is a fused three-phase anti-ferroresonance voltage transformer designed for 3.6kV, 7.2kV, and 12kV insulation classes corresponding to 3kV, 6kV, and 10kV system voltages. It features cast-resin insulation, operates within -5°C to +40°C ambient temperature at altitudes up to 1000 m, complies with IEC 61869 standards, and supports rated outputs up to 600VA.
Model Variants and Technical Data
| Model | Rated Voltage Ratio |
Accuracy Class / Rated Output |
Limit Output (VA) |
Rated Insulation Level (kV) |
|---|---|---|---|---|
| JSZJK-3R | 3000/√3 / 100/√3 / 100 | 0.2/6P(3P)—45/100 0.5/6P(3P)—100/100 1/6P(3P)—150/100 |
600 | 3.6/25/40 |
| JSZJK-6R | 6000/√3 / 100/√3 / 100 | 0.2/6P(3P)—45/100 0.5/6P(3P)—100/100 1/6P(3P)—150/100 |
600 | 7.2/30/60 |
| JSZJK-10R | 10000/√3 / 100/√3 / 100 | 0.2/6P(3P)—45/100 0.5/6P(3P)—100/100 1/6P(3P)—150/100 |
600 | 12/42/75 |
| 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 |
500 | 7.2/30/60 |
| 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 |
500 | 12/42/75 |
| 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 |
600 | 7.2/30/60 |
| 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 |
600 | 12/42/75 |
Installation & Wiring
Installation Diagram
The JSZJK-3/6/10R transformer is designed for secure mounting on a flat, stable surface with adequate clearance for ventilation and maintenance. Ensure the base dimensions (455mm length by 425mm width) align with the mounting structure. Primary terminals must remain accessible for connection and inspection.
Wiring Diagram
Primary terminals are labeled for A, B, and C phases with 210mm + 210mm spacing. Secondary terminals may include 1a, 1b, 1c, 2a, 2b, 2c, and da depending on the winding configuration. For residual-voltage protection applications, verify the open-delta (da) terminal arrangement as shown in the wiring diagram. Always confirm terminal polarity, proper grounding, and fuse integrity before energizing the unit.
Selection & FAQs
Selection Guide
- Match system voltage: select JSZJK-3R, -6R or -10R with the corresponding 3.6/25/40kV, 7.2/30/60kV or 12/42/75kV insulation level.
- Choose the secondary package: use the standard measuring/protection version, dual 100/√3V circuits, or the 220/√3V auxiliary version according to metering, monitoring and cabinet-load needs.
- Coordinate accuracy and burden: select the stated class and VA per winding; 500VA or 600VA limit output is thermal capability, not guaranteed measurement accuracy.
- Validate anti-ferroresonance duty: provide the neutral-grounding method, network capacitance, switching scenario and relay scheme because the source gives no universal suppression performance.
- Approve the complete assembly: confirm fuse type and rating, 455 × 425mm base, approximately 102kg mass, terminal diagram, −5°C standard minimum, grounding and lifting provisions.
Frequently Asked Questions
Q1: What system voltages are supported by this anti-ferroresonance voltage transformer?
It supports 3kV, 6kV, and 10kV system voltages. Corresponding insulation classes are 3.6kV, 7.2kV, and 12kV. Select the specific model variant based on your switchgear rating.
Q2: Which accuracy classes are available for metering and protection?
Metering classes include 0.2, 0.5, and 1, while protection classes are 3P and 6P. Rated outputs range from 45VA to 150VA with a 600VA limit. Specify your exact burden requirements during ordering.
Q3: Can this cast-resin voltage transformer be installed outdoors?
No, it is strictly designed for indoor installation. The environment must be non-corrosive, free from severe vibration, and without explosive hazards. Confirm your switchgear room conditions before placement.
Q4: Why choose a fused anti-ferroresonance design for medium voltage switchgear?
This design prevents ferroresonance overvoltages during single-phase grounding or switching operations. The integrated fuses provide short-circuit protection for the transformer. Consult our engineering team for specific application reviews.
Q5: What international standards does this three-phase voltage transformer comply with?
The JSZJK-3/6/10R series fully complies with IEC 61869 standards. Factory type tests and routine tests are conducted per these guidelines. Request the specific test certificates for your project documentation.
Q6: How long is the lead time for custom voltage ratios?
Standard models ship according to our current production schedule. Custom voltage ratios or specific accuracy combinations are subject to confirmation. Contact our sales team with your exact specifications for a precise delivery estimate.
Q7: What applications are suitable for this 12kV fused voltage transformer?
It is ideal for indoor 3kV, 6kV, and 10kV medium voltage switchgear and distribution panels. The anti-ferroresonance feature ensures stable voltage measurement for relay protection and metering. Specify your panel type for compatibility checks.