Overview
The JLSY12-11W is an outdoor oil-immersed combined transformer rated for 11kV medium-voltage systems. It integrates both current transformer (CT) and voltage transformer (PT) functions into a single three-phase three-component assembly, using high-quality transformer oil for insulation and cooling, with porcelain bushings for reliable outdoor performance.
This CT PT combined transformer delivers high measurement accuracy suitable for revenue metering and protection applications. It complies with GB20840.4-2015 and IEC 61869.4:2013 standards, making it ideal for international utility projects, industrial substations, and compact outdoor distribution networks requiring precise three-phase energy monitoring under varying load conditions.
Key Ratings Snapshot
| Parameter | Rating |
|---|---|
| System Voltage | 11kV |
| Insulation Medium | Oil-immersed |
| Configuration | Three-phase three-component |
| Current Range | 5A to 600A |
| Voltage Output | 100/√3 V (phase-to-ground) |
| Metering Accuracy Class | 0.2S / 0.5 |
| Protection Accuracy Class | 5P10 / 10P10 |
| Frequency | 50Hz |
| Bushing Type | Porcelain |
| Standards Compliance | GB20840.4-2015, IEC 61869.4:2013 |
| Installation Environment | Outdoor |
| Cooling Method | Natural oil convection |
Model Designation
- J: Combined instrument transformer (CT + PT)
- L: Outdoor (pole or substation mounting)
- S: Three-phase
- Y: Oil-immersed insulation
- 12: Design series number
- 11: Rated system voltage (11kV)
- W: Wide current range (5A–600A)
Construction
The JLSY12-11W features a robust oil-immersed construction with a sealed tank filled with high-grade insulating oil, providing both electrical insulation and efficient heat dissipation. The core and windings are fully immersed in oil, ensuring stable thermal performance in outdoor environments with high ambient temperatures. Porcelain bushings are used for all primary and secondary terminals, offering excellent dielectric strength and weather resistance. The three-phase three-component design incorporates separate magnetic circuits for each phase, minimizing cross-coupling and enhancing measurement accuracy under unbalanced load conditions. A dedicated secondary terminal box provides secure and insulated connections for metering and protection circuits, while the overall structure is designed for direct outdoor mounting on poles or substation structures without additional enclosures.
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 JLSY12-11W is an outdoor oil-immersed combined transformer designed for 11kV three-phase systems. It features oil-immersed insulation with porcelain bushings, operates within a temperature range of -25°C to +55°C, and is suitable for altitudes up to 4500m without derating. The unit complies with GB20840.4-2015 and IEC 61869.4:2013 standards and supports a primary current range from 5A to 600A.
Voltage Transformer Data
| Voltage
Ratio |
Insulation Level (kV) |
Accuracy Class |
Rated Output (VA) |
Max Output (VA) |
|---|---|---|---|---|
| 10/0.1 | 12/30/75 | 0.2 | 3×10 | 3×300 |
Current Transformer Data
| Primary Current (A) |
Insulation Level (kV) |
Accuracy Class |
Rated Output (VA) |
Short-Time Thermal Current |
Dynamic Current |
|---|---|---|---|---|---|
| 5 – 600 | 12/30/75 | 0.2S | 3×10 | 80 × I1n | 200 × I1n |
Installation & Wiring
Installation Diagram
The JLSY12-11W outdoor oil-immersed combined transformer is designed for pole-mounted or platform installation. Ensure the mounting structure can support the total weight of 148kg, including 34kg of insulating oil. Position the unit with clear access to bushings, grounding points, and the meter box. Maintain safe clearance distances as per local electrical codes.
Wiring Diagram
Wiring connections must follow the approved project diagram. The primary terminals are labeled AP1/AP2, BP1/BP2, and CP1/CP2 for phases A, B, and C respectively—verify sequence before energizing. The current transformer (CT) secondary terminals supply current signals to active and reactive energy meters and must never be left open-circuited during operation. The potential transformer (PT) secondary terminals provide voltage input to meters and monitoring devices. All grounding conductors and meter box wiring must comply with the specified wiring diagram and local regulations.
Selection & FAQs
Selection Guide
- Confirm the 11kV three-phase system, frequency, voltage ratio, grounding, and metering connection.
- Select the 5A–600A CT ratio from expected load current and choose the required secondary configuration.
- Specify CT and PT accuracy, rated output, meter burden, and complete cable-loop burden.
- Confirm altitude, temperature, pollution, porcelain creepage, oil specification, grounding, and surge protection.
- Verify the 148kg support load, line clearances, terminal sequence, meter box, oil access, and approved drawing.
Frequently Asked Questions
Q1: Can this combined transformer be used in high-altitude areas?
Yes, it operates up to 4500m without derating. The JLSY12-11W is designed for outdoor pole-mounted or substation applications in extreme environments. Contact us for specific high-altitude project requirements.
Q2: Which accuracy class is provided for the voltage transformer?
The voltage transformer features a 0.2 accuracy class with a 10/0.1 ratio. It delivers a rated output of 3×10VA and maximum output of 3×300VA. Confirm your specific burden requirements with our engineering team.
Q3: What maintenance is required for this oil-immersed unit?
Periodic oil level checks and oil quality inspections are required. Ensure the grounding terminal is connected according to local electrical codes. Refer to the manual for detailed maintenance schedules.
Q4: Are there international standards for this 11kV combined transformer?
It complies with GB20840.4-2015 and IEC 61869.4:2013 standards. These certifications ensure reliable performance for three-phase outdoor metering and protection systems. Request the official test certificates during your inquiry.
Q5: Can the primary current range be customized for our project?
The standard primary current range is 5A to 600A. Custom ratios are subject to factory confirmation based on your single-line diagram. Please provide your exact specifications for a tailored quote.
Q6: Where is the JLSY12-11W combined transformer typically applied?
It is an outdoor three-phase oil-immersed combined transformer used for 11kV systems. Ideal for pole-mounted installations, substations, and distribution points. Contact our sales team for regional availability and pricing.
Q7: How is the insulation level configured for this unit?
The unit uses oil-immersed insulation with porcelain bushings, rated at 12/30/75kV. This configuration supports 50Hz or 60Hz rated frequencies in ambient temperatures from -25°C to +55°C. Verify environmental conditions before final order.