Overview
The JSJW-3/6/10G is a three-phase indoor vertical oil-immersed voltage transformer designed for 3kV, 6kV, and 10kV AC power systems. It accurately steps down the primary system voltage to a standardized 100V secondary output, enabling safe and reliable operation of metering instruments, voltage monitoring devices, control circuits, and relay protection equipment.
This transformer features an oil-filled insulation system that provides excellent dielectric strength and thermal stability, making it ideal for continuous-duty applications in medium-voltage indoor substations and switchgear panels where precise voltage transformation is critical.
Key Ratings Snapshot
| Parameter | Value |
|---|---|
| Product Type | Three-phase voltage transformer |
| Installation | Indoor, vertical |
| Insulation | Oil-immersed |
| Rated Voltage Class | 3kV / 6kV / 10kV |
| Primary:Secondary Ratio | 3000:100 / 6000:100 / 10000:100 V |
| Rated Secondary Voltage | 100 V |
| Rated Frequency | 50 Hz or 60 Hz |
| Pollution Class | Class II |
| Main Function | Metering, monitoring, control, relay protection |
| Core Material | Cold-rolled silicon steel |
Model Designation
- J: Voltage transformer
- S: Three-phase structure
- J: Oil-immersed insulation
- W: Five-prop terminal arrangement
- 3/6/10: Rated voltage grade (3kV, 6kV, or 10kV)
- G: Manufacturer-specific design variant
Construction
The JSJW-3/6/10G features a robust cylindrical steel oil tank housing a laminated cold-rolled silicon steel core and precision-wound primary and secondary coils. The oil-immersed design ensures superior insulation performance and efficient heat dissipation during continuous operation. Primary terminals are mounted on top via porcelain bushings, while secondary terminals and a dedicated M12 grounding bolt are accessible at the base for safe and secure connections.
All units include provisions for oil filling and draining, with sealing mechanisms designed to maintain long-term integrity under standard indoor operating conditions. The vertical orientation optimizes space usage in compact indoor switchgear and metering compartments.
Technical Parameters
Service Conditions
- Installation Environment: Indoor only
- Ambient Temperature: -5 deg C to +40 deg C
- Altitude: <= 1000 m (unless specified otherwise)
- Pollution Class: Class II
- Relative Humidity: <= 95% (non-condensing)
Technical Data
| Model | Rated Primary Voltage (V) |
Secondary Voltage (V) |
Frequency (Hz) |
Insulation Type |
Accuracy Class |
Rated Output (VA) |
|---|---|---|---|---|---|---|
| JSJW-3 | 3000 | 100 | 50/60 | Oil-immersed | Per spec | Per accuracy class |
| JSJW-6 | 6000 | 100 | 50/60 | Oil-immersed | Per spec | Per accuracy class |
| JSJW-10 | 10000 | 100 | 50/60 | Oil-immersed | Per spec | Per accuracy class |
Installation & Wiring
Installation Diagram
Proper installation requires adherence to dimensional clearances, terminal orientation, and grounding practices. The transformer must be mounted vertically on a rigid base using the provided fixing holes. Primary terminals are located at the top; secondary wiring and grounding must follow approved schematics. Ensure adequate clearance for maintenance, ventilation, and electrical safety.
Outline Dimensions
| Model | Overall Height (mm) |
Tank Diameter (mm) |
Base Fixing Distance (mm) |
Mounting Holes |
Grounding Bolt |
|---|---|---|---|---|---|
| JSJW-6 | 705 | phi368 | 248 | 4-phi18 | M12 |
| JSJW-10 | 874 | phi472 | 320 | 4-phi18 | M12 |
Note: JSJW-3 dimensions must be confirmed from final approved drawings.
Selection & FAQs
Selection Guide
- Select model (JSJW-3/6/10) based on system voltage: 3kV, 6kV, or 10kV.
- Confirm voltage ratio matches primary system and secondary device input (e.g., 10000:100 for 10kV).
- Choose accuracy class per application: higher class (e.g., 0.2, 0.5) for revenue metering; standard class (e.g., 1.0, 3P) for monitoring or protection.
- Calculate total secondary burden (meters + relays + wiring loss) and ensure it does not exceed rated output at selected accuracy class.
- Verify indoor installation environment meets service conditions (temperature, humidity, pollution class).
Frequently Asked Questions
Q1: Can the JSJW-10KV voltage transformer be installed outdoors?
No, it is strictly designed for indoor installation only. The service conditions specify an indoor environment with a pollution class of II. Ensure your switchgear meets these environmental requirements prior to installation.
Q2: How to select the correct accuracy class and rated output?
Selection depends entirely on the connected burden of your meters and relays. The total secondary load must not exceed the rated output at your required accuracy class. Confirm your specific burden details with our engineering team.
Q3: What is the maximum operating altitude for this transformer?
The standard maximum operating altitude is 1000 meters. For installations exceeding this altitude, special design modifications are required. Contact our sales team to discuss high-altitude customization options for your specific project.
Q4: Which factory tests are performed before shipment?
Standard routine tests are conducted prior to dispatch to ensure compliance with technical specifications. Specific type tests or special certification requirements are subject to confirmation. Please provide your project specifications for detailed test documentation.
Q5: Are custom primary voltage models available for this series?
The JSJW series is standardly available in 3kV, 6kV, and 10kV primary voltage models. Custom voltage ratios are subject to factory confirmation. Specify your exact system voltage when requesting a formal quotation.
Q6: When should the total secondary load be verified?
Verification must occur before finalizing the order to prevent measurement errors. The total secondary load must not exceed the rated output at the required accuracy class. Provide your exact meter and relay wiring details for final validation.
Q7: Why choose a three-phase oil-immersed voltage transformer for 10kV?
They provide reliable voltage measurement and protection for indoor 3kV to 10kV distribution systems. The oil-immersed insulation ensures stable performance in Class II pollution environments. Contact us to verify suitability for your specific grid application.