Overview
The JLSY-6/10 is an outdoor oil-immersed combined transformer designed for 6kV and 10kV three-phase medium-voltage distribution systems. It integrates both current transformer (CT) and voltage transformer (PT) functions into a single cast-resin and oil-insulated assembly, featuring porcelain bushings and a three-phase three-component configuration with star-connected PTs.
This CT PT combined transformer delivers high measurement accuracy with classes up to 0.2S for metering and 0.5 for protection applications. It is suitable for outdoor substations, rural distribution networks, industrial facilities, and utility revenue metering. The unit complies with GB20840.4-2015 standards and operates reliably in ambient temperatures ranging from -15°C to +55°C.
Key Ratings Snapshot
| Parameter | Rating |
|---|---|
| Voltage Class | 6kV / 10kV |
| System Frequency | 50 Hz |
| Insulation Medium | Oil-immersed (45# transformer oil) |
| Primary Voltage (PT) | 6kV or 10kV |
| Secondary Voltage (PT) | 100/√3 V |
| Primary Current (CT) | 5A – 300A |
| Secondary Current (CT) | 5A or 1A |
| Metering Accuracy (CT) | 0.2S, 0.2 |
| Protection Accuracy (CT) | 0.5 |
| PT Accuracy Class | 0.2, 0.5 |
| Connection Type | Three-phase, star-connected PTs |
| Applicable Standard | GB20840.4-2015 |
Model Designation
- J: Voltage transformer (Chinese designation)
- L: Current transformer integrated
- S: Three-phase combined unit
- Y: Oil-immersed insulation
- 6/10: Rated system voltages of 6kV and 10kV
Construction
The JLSY-6/10 features a robust outdoor construction with an oil-immersed tank filled with high-quality 45# transformer oil, providing superior insulation and heat dissipation. The core and windings are sealed within the oil-filled enclosure, protected by high-strength porcelain bushings for primary connections. The secondary terminal box is weatherproof and accessible for wiring to meters and relays. The three-phase three-component design incorporates star-connected voltage transformers and toroidal current transformers, ensuring balanced phase performance and accurate signal output under varying load conditions. All materials are selected for long-term stability in harsh outdoor environments, with corrosion-resistant hardware and UV-resistant paint finish on the metal housing.
Technical Parameters
Service Conditions
- Installation position: Outdoor pole-mounted, substation, or distribution points
- Ambient temperature: -15°C to +55°C
- Maximum altitude: ≤ 4500m (no derating required)
- Insulation: Oil-immersed with porcelain bushings
- Oil type: 45# transformer oil
- 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-6/10 is an outdoor oil-immersed combined transformer designed for 6kV and 10kV three-phase systems. It features oil-immersed insulation with porcelain bushings, operates within a temperature range of -15°C to +55°C, and is suitable for installations up to 4500m altitude without derating. Compliant with GB20840.4-2015, it supports current transformer ratios from 5A to 300A.
Voltage Transformer Data
| Rated Voltage Ratio (V) |
Accuracy
Class |
Rated Output(VA) |
Insulation Level (kV) |
|---|---|---|---|
| 6000/√3 / 100/√3 / 100/3 | 0.2 | 30 | 7.2/32/60 |
| 10000/√3 / 100/√3 / 100/3 | 0.5 | 40 | 12/42/75 |
| 11000/√3 / 110/√3 / 110/3 | 0.5 | 60 | 12/42/75 |
Current Transformer Data
| Current Ratio (A) |
Accuracy
Class |
Output (VA) |
Short-Time Thermal Current |
Dynamic Current |
Insulation Level (kV) |
|---|---|---|---|---|---|
| 5 – 300/5 | 0.2S | 15 | 60 × I1n | 150 × I1n | 12/42/75 |
| 5 – 300/5 | 0.2 | 15 | 60 × I1n | 150 × I1n | 12/42/75 |
| 5 – 300/5 | 0.5 | 20 | 60 × I1n | 150 × I1n | 12/42/75 |
Installation & Wiring
Installation Diagram
The JLSY-6/10 outdoor oil-immersed combined transformer is designed for pole or platform mounting. Ensure the mounting structure accommodates the base width of 320/374mm and provides secure anchoring. Maintain clearances as per local electrical codes, and verify that the three porcelain bushings (spaced 180mm apart) align with incoming conductors.
Wiring Diagram
Wiring connections must follow the approved project diagram. Confirm terminal sequence for high-voltage phases: AP1/AP2, BP1/BP2, and CP1/CP2 before commissioning. The PT secondary terminals supply voltage signals to meters and monitoring equipment, while the CT secondary terminals provide current inputs to active and reactive energy meters. All CT secondary circuits must remain closed during operation to prevent dangerous overvoltages. Grounding and meter box wiring must comply with the project-specific wiring diagram.
Selection & FAQs
Selection Guide
- Select the 6kV or 10kV variant and verify the star-connected three-phase metering scheme.
- Specify the PT ratio and outputs, then choose the 5A–300A CT ratio and 1A or 5A secondary.
- Define CT and PT accuracy and calculate the burden for active and reactive metering circuits.
- Confirm altitude, temperature, pollution, porcelain creepage, oil, grounding, and surge-protection requirements.
- Verify pole or platform dimensions, bushing alignment, line clearances, terminal sequence, oil access, and drawing.
Frequently Asked Questions
Q1: Can this oil-immersed transformer operate at high altitudes?
Yes, it operates up to 4500m without derating. The design accommodates ambient temperatures from -15°C to +55°C. Confirm specific requirements for extreme climates with our team.
Q2: Which accuracy class is suitable for precision metering?
The 0.2 class provides 30VA output for precision metering, while the 0.5 class offers 40VA for standard measurements. Specify your exact load requirements during inquiry.
Q3: How should the grounding terminal be connected during installation?
Connect the grounding terminal strictly according to local electrical codes and metering standards. Periodic oil level and quality inspections are required for ongoing maintenance.
Q4: What national standards does this combined transformer comply with?
The JLSY-6/10 is fully compliant with the GB20840.4-2015 standard. Contact our sales department for details regarding specific compliance certificates and factory test reports.
Q5: Are custom current transformer ratios available for this model?
Yes, standard current transformer ratios range from 5A to 300A. Custom ratio configurations are subject to confirmation based on your specific project requirements.
Q6: Where is this three-phase combined transformer typically installed?
It is designed for outdoor pole-mounted, substation, or distribution point applications in 6kV and 10kV systems. Contact us for site-specific application engineering.
Q7: When is periodic oil maintenance required for this unit?
Routine maintenance requires periodic oil level checks and oil quality inspections. Consult the operation manual for specific inspection intervals and procedures.