Overview
The JSZF-3/6/10kV series voltage transformers are precision electromagnetic instruments designed for accurate voltage measurement, energy metering, and relay protection in 3-12kV indoor AC power systems. Utilizing electromagnetic induction, they deliver galvanically isolated secondary voltage signals proportional to the primary system voltage, ensuring safe and reliable operation for critical monitoring and control functions.
Built with durable epoxy resin insulation and a compact semi-enclosed design, these transformers offer superior electrical performance, mechanical strength, and installation convenience. They are ideal for use in substations, industrial facilities, and medium-voltage switchgear, meeting stringent accuracy and reliability requirements under normal indoor service conditions.
Key Ratings Snapshot
| Parameter | Value |
|---|---|
| System voltage class | 3kV / 6kV / 10kV (indoor) |
| Rated frequency | 50 Hz (60 Hz on request) |
| Rated secondary voltage | 100/sqrt(3) V or 100 V |
| Accuracy classes | 0.2, 0.5, 1, 3, 6P (metering/protection) |
| Rated burden | Per core/winding (VA) |
| Burden power factor | cos phi = 0.8 (lagging) |
| Max output capacity | 1000 VA |
| Insulation system | Epoxy resin cast |
| Design type | Semi-enclosed, indoor |
| Model variants | JSZF-3, JSZF-6, JSZF-10 |
Model Designation
- J: Voltage transformer (VT)
- S: Three-phase / Single-phase configuration
- Z: Cast epoxy resin insulated structure
- F: Semi-enclosed design
- 3 / 6 / 10: Voltage class (kV)
Construction
The JSZF series features a semi-enclosed epoxy resin cast construction that ensures excellent insulation performance, moisture resistance, and long-term mechanical stability. The compact form factor is optimized for installation in medium-voltage indoor switchgear, maintaining required electrical clearances and creepage distances while allowing accessibility for inspection.
The integrated primary and secondary insulation system, combined with an optimized magnetic core design, delivers consistent accuracy and thermal performance. This robust build supports reliable operation in light to moderate pollution environments, making it suitable for demanding industrial and utility applications.
Technical Parameters
Service Conditions
- Installation environment: Indoor only (vertical mounting recommended)
- Altitude: <= 1000 m above sea level (higher on request)
- Ambient temperature: -5 degC to +40 degC
- Relative humidity: <=95%, no condensation
- Pollution degree: Light to moderate
- Environmental conditions: Free from corrosive gases, explosive media, severe vibration, or mechanical shock
Technical Data
| Model | Rated Voltage Ratio (V) |
0.2 Class (VA) |
0.5 Class (VA) |
1 Class (VA) |
3 Class (VA) |
6P Class (VA) |
Max Output (VA) |
Insulation Level (kV) |
|---|---|---|---|---|---|---|---|---|
| JSZF-3 | 3000/sqrt(3) / 100/sqrt(3) / 100/3 | 60 | 150 | 300 | 450 | 50 | 1000 | 3.6/25/40 |
| JSZF-6 | 6000/sqrt(3) / 100/sqrt(3) / 100/3 | 60 | 150 | 300 | 450 | 50 | 1000 | 7.2/32/60 |
| JSZF-10 | 10000/sqrt(3) / 100/sqrt(3) / 100/3 | 75 | 150 | 300 | 450 | 50 | 1000 | 12/42/75 |
Installation & Wiring
Installation Diagram
Proper wiring and mounting are essential for safe and accurate operation. Connect primary conductors per nameplate instructions and ensure secondary circuits include appropriately rated fuses. For JSZF-3 and JSZF-6 models, the O terminal must be grounded during fault conditions to coordinate with ground fault protection systems.
Outline Dimensions
| Dimension | Value (mm) |
|---|---|
| Height | As per dimensional drawing |
| Width | As per dimensional drawing |
| Depth | As per dimensional drawing |
| Mounting hole pattern | As per dimensional drawing |
| phi Primary terminal | As per model variant |
Selection & FAQs
Selection Guide
- Specify model (JSZF-3/6/10) based on system voltage class.
- Select accuracy class combination (e.g., 0.2 for metering, 6P for protection) per application need.
- Define rated burden (VA) for each secondary winding to match connected devices.
- Confirm secondary voltage configuration: 100/sqrt(3) V or 100 V.
- Verify indoor environmental conditions meet service limits (temp, humidity, altitude).
Frequently Asked Questions
Q1: Can this epoxy resin voltage transformer be installed outdoors?
No, it is strictly for indoor installation only. The design requires a pollution-free environment without severe vibration or mechanical shock. Contact us for outdoor-rated alternatives.
Q2: Which accuracy class is suitable for protective relaying?
The 6P class is designed for protection circuits, offering 50 VA output. For metering applications, select the 0.2 or 0.5 class. Maximum output capacity is 1000 VA.
Q3: What is the insulation level for the JSZF-10 model?
The JSZF-10 model features a 12/42/75 kV insulation level. This ensures reliable performance in 10kV indoor switchgear systems. Confirm specific dielectric test requirements with our engineering team.
Q4: Can the operating altitude exceed 1000 meters above sea level?
Standard models are rated for altitudes up to 1000 meters. Higher altitude applications require custom design adjustments for dielectric strength. Please provide your exact site altitude for factory evaluation.
Q5: What routine factory tests are performed before shipment?
Standard routine tests verify voltage ratio, polarity, and basic insulation. Specific type tests or third-party certifications are subject to project confirmation. All parameters strictly follow standard manufacturing protocols.
Q6: Where is this semi-enclosed voltage transformer typically applied?
It is primarily used in 3kV, 6kV, and 10kV indoor switchgear for voltage measurement. Ensure the ambient temperature remains between -5°C and +40°C. Contact us to verify suitability for your specific application.
Q7: Are custom voltage ratios available for this transformer series?
Standard primary ratios are 3000, 6000, and 10000V. Custom voltage ratios or specific secondary burden requirements are subject to factory confirmation. Contact our technical team with your single-line diagram.