Overview
The JSZJK-6Q and JSZJK-10Q are dry-type, anti-ferroresonance three-phase five-limb voltage transformers rated for 7.2kV and 12kV systems, respectively. They feature a semi-enclosed, epoxy cast-resin insulation system suitable for indoor installation in medium-voltage switchgear.
Designed for 50Hz or 60Hz power systems, these transformers support voltage measurement, energy metering, and relay protection functions. They comply with relevant IEC and GB standards for accuracy and insulation performance, ensuring reliable operation in distribution networks where ferroresonance suppression is critical.
Key Ratings Snapshot
| Parameter | Rating |
|---|---|
| System Voltage (Ur) | 7.2kV (JSZJK-6Q), 12kV (JSZJK-10Q) |
| Frequency | 50Hz / 60Hz |
| Insulation Class | Epoxy cast-resin, indoor use |
| Phase Configuration | Three-phase |
| Magnetic Core | Five-limb structure |
| Secondary Windings | One or two |
| Accuracy Class (Metering) | 0.2, 0.5 (as per configuration) |
| Accuracy Class (Protection) | 3P, 6P (as per configuration) |
| Thermal Burden | Per IEC 61869-3 |
| Auxiliary Function | Anti-ferroresonance design |
| Installation Environment | Indoor, non-condensing |
| Primary Voltage Options | 6kV, 10kV (nominal) |
Construction
The JSZJK-6Q and JSZJK-10Q feature a semi-enclosed dry-type construction with all main insulation components encapsulated in epoxy cast-resin. This provides excellent dielectric strength, moisture resistance, and mechanical robustness. The core employs a three-phase five-limb magnetic arrangement, specifically engineered to suppress ferroresonance under single-phase grounding or switching transients. The compact, solid design eliminates the need for oil or gas insulation, making it ideal for indoor switchgear panels. Secondary windings are configured for either single or dual output, supporting combined metering and protection circuits within the same unit.
Technical Parameters
Service Conditions
- Ambient temperature: -25°C to +40°C
- Installation environment: Indoor
Technical Parameters
The JSZJK-6 and JSZJK-10Q are dry-type anti-ferroresonance three-phase five-limb voltage transformers with semi-enclosed epoxy cast-resin insulation, designed for indoor use in 3.6kV, 7.2kV, and 12kV systems. They operate at 50Hz or 60Hz within an ambient temperature range of -25°C to +40°C and comply with GB20840.3-2013 and IEC61869-3:2011 standards.
Model Variants
| Item | Specification |
|---|---|
| Model series | JSZJK-3Q, JSZJK-6Q, JSZJK-10Q |
| Product type | Dry-type anti-ferroresonance three-phase five-limb voltage transformer |
| Insulation structure | Semi-enclosed epoxy cast-resin |
| Installation | Indoor |
| Structure | Three-phase five-limb |
| Frequency | 50Hz / 60Hz |
| Voltage classes | 3.6kV, 7.2kV, 12kV |
| Main function | Voltage measurement, energy metering, relay protection |
| Standards | GB20840.3-2013, IEC61869-3:2011 and special project requirements |
| Ambient temperature | -25°C to +40°C |
Technical Data
| Type | Voltage Ratio(V) |
Accuracy class / Rated output (VA) |
Limit output(VA) |
Rated insulated level(kV) |
|---|---|---|---|---|
| JSZJK-3Q | 3000/√3 : 100/√3 : 100/√3 | 0.2/6P(3P)—20/100 | 600 | 3.6/25/40 |
| JSZJK-6Q | 6000/√3 : 100/√3 : 100/√3 | 0.5/6P(3P)—40/100 | 7.2/30/60 | |
| JSZJK-10Q | 10000/√3 : 100/√3 : 100/√3 | 1/6P(3P)—80/100 | 12/42/75 | |
| JSZJK-6Q | 6000/√3 : 100/√3 : 100/√3 : 100/√3 | 0.2/0.2/6P(3P)—15/15/100 | 500 | 7.2/30/60 |
| JSZJK-10Q | 10000/√3 : 100/√3 : 100/√3 : 100/√3 | 0.5/0.5/6P(3P)—20/20/100 | 12/42/75 | |
| JSZJK-6Q | 6000/√3 : 100/√3 : 220/√3 : 100/3 | 0.2/3/6P(3P)—15/400/100 | 500 | 7.2/30/60 |
| JSZJK-10Q | 10000/√3 : 100/√3 : 220/√3 : 100/3 | 0.5/3/6P(3P)—20/400/100 | 12/42/75 |
Installation & Wiring
Installation Diagram
The JSZJK-6 and JSZJK-10Q anti-ferroresonance three-phase voltage transformers feature a large integrated three-phase structure designed for indoor installation. Mounting dimensions and overall outline must be verified against the approved engineering drawing prior to production. Key dimensional references include an overall length of 688 mm, mounting/body length of 643 mm, top spacing of 208±3 / 150±3 / 150±3 mm, overall width of 280 mm, side width of 168 mm, overall height of 295 mm, and body height reference of 170±3 mm. The unit weighs approximately 81.6 kg.
Wiring Diagram
Wiring connections must follow the provided wiring diagram. Terminals are clearly marked for primary and secondary windings, with designated terminals for phase A, B, C, and neutral (N). Secondary outputs include voltage measurement terminals and auxiliary windings configured to suppress ferroresonance. Ensure all connections comply with local electrical codes and manufacturer specifications.
Selection & FAQs
Selection Guide
- Choose the voltage model: use JSZJK-6Q for 6/√3kV primary voltage and 7.2kV-class insulation, or JSZJK-10Q for 10/√3kV and 12kV-class insulation.
- Select the winding package: choose measurement plus 100V protection, dual 100/√3V measuring circuits, or the 220/√3V auxiliary version according to the project schematic.
- Coordinate accuracy and load: match class 0.2, 0.5 or 1 and class 3P/6P to each listed VA; treat 500VA or 600VA only as thermal output.
- Validate anti-ferroresonance performance: submit the neutral-grounding method, system capacitance and switching conditions because the five-limb design is not a universal suppression guarantee.
- Approve enclosure integration: verify the semi-enclosed construction, 688 × 280 × 295mm outline, 81.6kg support, terminal diagram, clearances, grounding and whether separate primary fuses are required.
Frequently Asked Questions
Q1: Why choose a five-limb core for anti-ferroresonance voltage transformers?
The three-phase five-limb core provides a zero-sequence magnetic path, effectively suppressing ferroresonance overvoltages. It is specifically designed for 3.6kV to 12kV ungrounded indoor systems.
Q2: Can this dry-type VT be installed outdoors?
No, this model is strictly designed for indoor installation only. It operates within an ambient temperature range of -25°C to +40°C and features semi-enclosed epoxy cast-resin insulation.
Q3: Which international standards does this voltage transformer comply with?
The JSZJK series complies with IEC61869-3:2011 and GB20840.3-2013 standards. Specific project requirements can also be accommodated subject to factory confirmation.
Q4: What voltage classes are available for the JSZJK series?
Standard models include 3.6kV, 7.2kV, and 12kV variants. Custom voltage ratios or specific project requirements are subject to factory confirmation.
Q5: Are routine factory tests provided before shipment?
Yes, standard routine tests are conducted to ensure compliance with IEC and GB standards. Contact our sales team for detailed test reports and specific certification requirements.
Q6: How is this 10kV VT typically applied in switchgear?
This dry-type anti-ferroresonance voltage transformer is primarily used for voltage measurement, energy metering, and relay protection in indoor switchgear. It supports both 50Hz and 60Hz power systems.
Q7: Is this transformer compatible with 60Hz power grids?
Yes, the JSZJK-6/10Q is designed to operate on both 50Hz and 60Hz frequencies. Please specify your grid frequency during the inquiry for accurate factory configuration.