Overview
The JLSY-10 is an outdoor oil-immersed combined transformer rated for 10kV medium-voltage systems. It integrates both current transformer (CT) and voltage transformer (PT) functions into a single three-phase three-component unit, featuring porcelain bushings and mineral oil insulation for reliable outdoor operation.
Designed for high-accuracy metering and protection applications, the JLSY-10 complies with GB20840.4-2015 and IEC 61869.4:2013 standards. It supports current ratings from 5A to 800A and offers dual voltage ratios (10/0.1kV and 11/0.11kV), making it suitable for utility revenue metering, industrial distribution networks, and compact outdoor substations requiring precise three-phase measurement.
Key Ratings Snapshot
| Parameter | Rating |
|---|---|
| System Voltage | 10kV |
| Primary Current Range | 5A – 800A |
| Voltage Ratio Options | 10/0.1kV, 11/0.11kV |
| Phase Configuration | Three-phase three-component |
| Insulation Medium | Mineral oil |
| Bushing Type | Porcelain |
| Metering Accuracy Class | 0.2 / 0.5 (voltage), 0.2S / 0.5S (current) |
| Protection Accuracy Class | 5P10 / 10P10 |
| Standards Compliance | GB20840.4-2015, IEC 61869.4:2013 |
| Installation Environment | Outdoor |
| Cooling Method | Natural oil convection |
| Secondary Terminals | Separate CT and PT terminals in weatherproof box |
Model Designation
- J: Combined instrument transformer (CT + PT)
- L: Outdoor (pole or substation mounting)
- S: Three-phase three-component configuration
- Y: Oil-immersed insulation
- 10: Rated system voltage of 10kV
Construction
The JLSY-10 features a robust oil-immersed design with a welded steel tank filled with insulating mineral oil. High-voltage and low-voltage windings are encapsulated within the oil-filled chamber, providing effective cooling and dielectric strength. Porcelain bushings are used for all primary and secondary connections, ensuring long-term outdoor reliability under varying environmental conditions. The secondary terminal box is sealed against moisture ingress and includes clearly labeled terminals for both CT and PT outputs. The three-phase three-component layout ensures symmetrical magnetic circuits for each phase, minimizing measurement errors under unbalanced load conditions. All external surfaces are treated with anti-corrosion coatings suitable for harsh outdoor environments.
Technical Parameters
Service Conditions
- Installation position: Outdoor pole-mounted, substation, or distribution points
- Ambient temperature: -25°C to +55°C
- Maximum altitude: ≤ 4500m (no derating required)
- Insulation: Oil-immersed with porcelain bushings
- Rated frequency: 50Hz or 60Hz
- Grounding: Connect grounding terminal per local electrical codes and metering standards
- Maintenance: Periodic oil level check and oil quality inspection required
Technical Parameters
The JLSY-10 is an outdoor oil-immersed combined transformer designed for 10kV three-phase systems. It features oil-immersed insulation with porcelain bushings, operates within -25°C to +55°C ambient temperature, and is suitable for installations up to 4500m altitude without derating. The unit complies with GB20840.4-2015 and IEC 61869.4:2013 standards, supporting primary current ratings from 5A to 800A.
Voltage Transformer Data
| Rated Voltage(kV) |
Insulation Level (kV) |
Accuracy Class | Rated Output (VA) |
Max
Output (VA) |
|---|---|---|---|---|
| 10/0.1 | 12/42/75 | 0.2 | 10 | 400 |
| 11/0.11 | 12/42/75 | 0.5 | 20 |
Current Transformer Data
| Primary Current (A) |
Insulation Level (kV) |
Accuracy
Class |
Rated Output (VA) |
Short-Time Thermal Current |
Dynamic Current |
|---|---|---|---|---|---|
| 5 – 600 | 12/42/75 | 0.2S | 3×15 | 80 × I1n | 200 × I1n |
| 750 – 800 | 12/42/75 | 0.2S | 3×20 | 80 kA | 200 kA |
Installation & Wiring
Installation Diagram
The JLSY-10 outdoor oil-immersed combined transformer is designed for pole-mounted or platform installation. Ensure the mounting structure can support the unit’s weight of approximately 130kg. Maintain clearances as per local regulations to allow safe access and ventilation. The front view shows three porcelain bushings with a liquid level gauge, while the side view provides access to the secondary terminal box and oil drain hole. The top view reveals six bushings arranged in a 2×3 configuration.
Wiring Diagram
Wiring connections must follow the approved project diagram. Confirm the terminal sequence for AP1/AP2, BP1/BP2, and CP1/CP2 before commissioning. The PT (potential transformer) secondary terminals supply voltage signals to meters and monitoring devices, while the CT (current transformer) secondary terminals provide current input to active and reactive energy meters. CT secondary circuits must never be left open-circuited during operation to prevent dangerous overvoltages. All grounding and meter box wiring must comply with the specified wiring diagram.
Selection & FAQs
Selection Guide
- Confirm the 10kV or applicable 11kV voltage ratio, frequency, system grounding, and three-phase metering scheme.
- Select the 5A–800A CT ratio from load current and choose the required metering or protection outputs.
- Specify CT and PT accuracy classes and calculate the burden of every secondary circuit.
- Confirm altitude, temperature, pollution, porcelain creepage, oil condition, grounding, and surge protection.
- Verify the approximately 130kg support load, six-bushing layout, clearances, terminal sequence, and oil access.
Frequently Asked Questions
Q1: Can this 10kV outdoor metering box operate at 4500m altitude?
Yes, it operates up to 4500m without derating. The unit features oil-immersed insulation with porcelain bushings for reliable high-altitude performance. Contact us for specific site condition verification.
Q2: Which accuracy class is provided for the voltage transformer?
The VT offers 0.2 and 0.5 accuracy classes with 10VA rated output. This ensures precise metering for 10kV and 11kV three-phase systems. Factory calibration certificates are available upon request.
Q3: What maintenance is required for the oil-immersed insulation?
Periodic oil level checks and oil quality inspections are required. The unit features porcelain bushings and standard grounding terminals per local electrical codes. Consult the manual for detailed schedules.
Q4: How does the unit handle extreme ambient temperatures?
It operates reliably within a -25°C to +55°C ambient temperature range. The oil-immersed design provides stable thermal performance for outdoor pole-mounted or substation installations. Specify your local climate details during ordering.
Q5: Which international standards does this metering box comply with?
The JLSY-10KV complies with GB20840.4-2015 and IEC 61869.4:2013 standards. It supports 50Hz or 60Hz rated frequencies for global power grids. Request the specific compliance certificates from our sales team.
Q6: Are factory tests performed before shipping the combined transformer?
Yes, standard routine tests are conducted prior to shipment to ensure quality. The primary current ratings range from 5A to 800A based on your specifications. Contact us for detailed test reports.
Q7: What applications suit this outdoor oil-immersed combined transformer?
It is designed for 10kV three-phase outdoor pole-mounted, substation, and distribution point applications. The combined transformer integrates precise voltage and current metering in one unit. Confirm your exact scenario with our engineers.
Q8: Where is this 10kV metering box typically installed?
It is typically installed at outdoor distribution points, substations, or pole-mounted locations. The compact oil-immersed design saves space while delivering accurate 10kV three-phase metering. Contact our team for site layout recommendations.