Overview
The JSZGF-3/6/10R is a fused three-phase anti-ferroresonance voltage transformer designed for indoor use in 3.6kV, 7.2kV, and 12kV medium-voltage switchgear. It features epoxy cast-resin insulation, providing high dielectric strength and mechanical stability in compact switchgear applications.
Built to meet IEC 61869 standards, this transformer delivers accurate secondary voltage signals for metering, monitoring, residual-voltage detection, and relay protection. Its integrated primary fuse and anti-ferroresonance design make it suitable for systems requiring reliable operation during grounding faults and transient conditions.
Key Ratings Snapshot
| Parameter | Rating |
|---|---|
| Voltage Class | 3.6kV / 7.2kV / 12kV |
| Insulation Level (Um/kV) | 3.6/25/40 or 12/42/75 |
| Primary Voltage | 3.6kV, 7.2kV, or 12kV (line-to-line) |
| Secondary Voltage | 100/√3 V (phase-to-neutral), 100 V (residual) |
| Accuracy Class | 0.5 / 3P or as specified |
| Burden | Up to 100 VA per winding |
| Frequency | 50 Hz or 60 Hz |
| Primary Fuse Rating | Integrated, matched to VT rating |
| Phase Configuration | Three-phase with open delta for residual voltage |
| Insulation Material | Epoxy cast-resin |
| Application Environment | Indoor, non-condensing |
| Standards Compliance | IEC 61869 series |
Construction
The JSZGF-3/6/10R is constructed with a fully enclosed epoxy cast-resin body, ensuring excellent insulation performance, moisture resistance, and mechanical robustness. The core and windings are vacuum-cast in epoxy resin under controlled conditions, eliminating air voids and enhancing partial discharge resistance. Primary windings include integrated current-limiting fuses housed within the same cast body, providing coordinated protection against internal faults. The anti-ferroresonance design incorporates optimized magnetic circuit parameters to suppress resonant overvoltages during single-phase grounding events. Terminal blocks for secondary connections are accessible from the front or top, depending on switchgear layout, and are clearly labeled for phase and residual outputs. The unit is designed for secure mounting in standard VT compartments of metal-clad or metal-enclosed indoor switchgear.
Technical Parameters
Service Conditions
- Ambient temperature: -25°C to +40°C
- Installation environment: Indoor switchgear installation
- Altitude: Not specified in source (assumed standard ≤1000m unless otherwise agreed)
- Humidity: Not explicitly specified in source
- Surface creepage distance: Complies with pollution class II requirements
Technical Parameters
The JSZGF-3/6/10R is a fused three-phase anti-ferroresonance voltage transformer with indoor epoxy cast-resin insulation, designed for rated voltage classes of 3.6kV, 7.2kV, and 12kV. It operates at 50Hz or 60Hz within an ambient temperature range of -25°C to +40°C and complies with GB20840.3-2013 and IEC61869-3:2011 standards.
Voltage Transformer Data
| Type | Rated Voltage (kV) |
Type (Ratio) |
Accuracy Class (Protection/ Measurement) |
Rated Output (VA) |
Rated Insulation Level (kV) |
|---|---|---|---|---|---|
| JSZGF-3R | 3.6 | 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 | 7.2 | 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 |
500 | 7.2/30/60 |
| JSZGF-10R | 12 | 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 |
500 | 12/42/75 |
| JSZGF-6R | 7.2 | 6000/√3 / 0.1/√3 / 0.1/√3 / 0.1/3 | 0.2/0.5/6P(3P)—10/15/100 | 500 | 7.2/30/60 |
| JSZGF-10R | 12 | 10000/√3 / 0.1/√3 / 0.1/√3 / 0.1/3 | 0.2/0.5/6P(3P)—10/15/100 | 500 | 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 & Wiring
Installation Diagram
The JSZGF-3/6/10R series must be installed in accordance with the approved outline drawing, wiring diagram, and switchgear layout. The unit features a three-phase integrated cast-resin structure with built-in fuse elements, multiple primary bushings, and grouped secondary terminals. Ensure proper alignment with the base reference dimensions and maintain required phase spacing during mounting.
Selection & FAQs
Selection Guide
- Match ratio and insulation: select JSZGF-3R, -6R or -10R using the listed phase-to-earth ratio and corresponding 3.6/25/40kV, 7.2/30/60kV or 12/42/75kV insulation.
- Select the winding package: choose one measuring winding plus residual protection, or the 6/10kV dual-measuring version when metering and monitoring need separation.
- Coordinate accuracy and burden: use class 0.2, 0.5 or 1 for measurement and 3P or 6P at 100VA for protection; 500VA is a thermal limit.
- Validate anti-ferroresonance duty: provide system grounding, capacitance and switching conditions because no universal suppression envelope or test curve is published.
- Approve fuse and installation data: confirm the 0.5A/50kA fuse, replacement clearance, terminal diagram, voltage factor, grounding, ambient range and switchgear outline.
Frequently Asked Questions
Q1: What rated voltage classes does this three-phase fused voltage transformer support?
It supports 3.6kV, 7.2kV, and 12kV rated voltage systems. The JSZGF-3/6/10R operates at 50Hz or 60Hz with epoxy cast-resin insulation. Select the specific model matching your switchgear rating.
Q2: Which accuracy classes are available for measurement and protection?
Available classes include 0.2, 0.5, and 1 for measurement, plus 3P and 6P for protection. Rated output is 500VA across all variants. Contact our engineering team to specify your exact ratio requirements.
Q3: Can this anti-ferroresonance voltage transformer be installed outdoors?
No, it is strictly designed for indoor switchgear installation. It features epoxy cast-resin insulation and complies with pollution class II requirements. Ensure indoor ambient temperatures remain between -25°C and +40°C.
Q4: What international standards does this 12kV voltage transformer comply with?
It fully complies with IEC 61869-3:2011 and GB20840.3-2013 standards. The rated insulation levels meet standard requirements for 3.6kV, 7.2kV, and 12kV systems. Request the specific type test report for your project documentation.
Q5: How do we order a custom primary to secondary ratio?
Standard ratios are provided for 3.6kV, 7.2kV, and 12kV classes as per the datasheet. Custom ratios are subject to factory confirmation based on your single-line diagram. Please provide your exact ratio requirements during inquiry.
Q6: Are routine factory acceptance tests performed before shipment?
Yes, standard routine tests are conducted prior to dispatch to ensure compliance with IEC 61869-3. Specific test certificates and inspection reports are provided upon request. Contact sales for detailed testing protocols and lead times.
Q7: What is the primary application of this epoxy cast voltage transformer?
It is primarily used for voltage measurement, protection, and anti-ferroresonance in indoor medium-voltage switchgear. The fused design ensures safe operation across 3kV to 12kV distribution networks. Reach out for manufacturer catalog details.