Overview
The JLS-6/10/11 is an outdoor oil-immersed combined transformer designed for 6kV, 10kV, 11kV, and 12kV medium-voltage distribution systems. It integrates current transformer (CT) and voltage transformer (PT) functions into a single three-phase unit, using high-quality 45# transformer oil for insulation and cooling, with porcelain bushings ensuring reliable outdoor performance.
This CT PT combined transformer delivers high measurement accuracy suitable for revenue metering, load monitoring, and protection applications. It complies with GB20840.4-2015 standards and is commonly deployed in rural distribution networks, industrial substations, and compact outdoor metering installations where precise energy measurement under varying environmental conditions is required.
Key Ratings Snapshot
| Parameter | Rating |
|---|---|
| Voltage Class | 6kV / 10kV / 11kV / 12kV |
| System Voltage (Um) | 7.2kV / 12kV |
| Insulation Level (kV) | 3.6/25/40, 7.2/32/60, 12/42/75 |
| Primary Current Range | 5A – 300A |
| Secondary Current | 5A or 1A |
| Secondary Voltage | 100V or 100/√3 V |
| Metering Accuracy (CT) | 0.2S / 0.5S |
| Protection Accuracy (CT) | 5P10 / 10P10 |
| PT Accuracy Class | 0.2 / 0.5 |
| Frequency | 50Hz |
| Ambient Temperature Range | -15°C to +55°C |
| Insulation Medium | 45# transformer oil |
Model Designation
- J: Voltage transformer (PT)
- L: Current transformer (CT)
- S: Three-phase combined unit
- 6/10/11: Rated system voltages (6kV, 10kV, 11kV); compatible with 12kV systems
Construction
The JLS-6/10/11 features a robust three-column cast-resin and oil-immersed structure housed in a sealed tank filled with 45# transformer oil. The primary and secondary windings are encapsulated within the oil-filled chamber, providing excellent dielectric strength and thermal stability. Porcelain bushings are used for all high-voltage terminals, offering superior weather resistance and creepage performance in outdoor environments. The secondary terminal box is IP54-rated, protecting connections to metering and protection devices. The entire assembly is designed for pole or platform mounting, with lifting hooks and grounding points integrated into the tank for safe installation and operation.
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 JLS-6/10/11 is an outdoor oil-immersed combined transformer designed for 6kV, 10kV, 11kV, and 12kV three-phase systems. It features oil-immersed insulation with porcelain bushings, operates within -15°C to +55°C ambient temperature, supports installation up to 4500m altitude without derating, complies with GB20840.4-2015, and offers current transformer ratios from 5A to 300A.
Model Variants
| Model | System Voltage |
Voltage Ratio |
Rated Insulation Level (kV) |
Application |
|---|---|---|---|---|
| JLS-6 | 6kV | 6000/100V | 7.2/32/60 | Chinese standard 6kV systems |
| JLS-10 | 10kV | 10000/100V | 12/42/75 | Chinese standard 10kV systems |
| JLS-11 | 11kV | 11000/110V | 12/42/75 | International 11kV systems |
| JLS-12 | 12kV | 12000/100V | 12/42/75 | International 12kV systems |
Voltage Transformer Data
| Rated Voltage Ratio |
Accuracy Class |
Rated Output (VA) |
Limit Output (VA) |
Rated Insulation Level (kV) |
|---|---|---|---|---|
| 3000/100 | 0.2 | 15 | 300 | 3.6/25/40 |
| 6000/100 | 0.5 | 30 | 7.2/32/60 | |
| 10000/100 | 0.5 | 30 | 12/42/75 |
Current Transformer Data
| Rated Current Ratio (A) |
Accuracy Class |
Rated Output (VA) |
Short-Time Thermal Current |
Dynamic Current |
Rated Insulation Level (kV) |
|---|---|---|---|---|---|
| 5 – 300/5 | 0.2S | 7.5 | 80 × I1n | 200 × I1n | 12/42/75 |
| 5 – 300/5 | 0.2 | 10 | 80 × I1n | 200 × I1n | 12/42/75 |
Installation & Wiring
Installation Diagram
The JLS-6/10/11 oil-immersed combined transformer metering box is designed for pole-mounted or platform installation. Ensure the mounting structure can support the unit’s weight of approximately 72kg. Align the base width (230/260/290mm) with the mounting brackets as per the project specifications. Maintain clear access to the front panel for meter reading and the oil level window, and ensure the top-mounted oil inlet and air release valve remain unobstructed.
Wiring Diagram
Selection & FAQs
Selection Guide
- Select the 6kV, 10kV, 11kV, or 12kV model and verify voltage ratio and insulation level.
- Choose the 5A–300A CT ratio and 1A or 5A secondary from the load and metering system.
- Specify CT and PT accuracy, rated output, meter burden, and cable-loop burden.
- Confirm altitude, temperature, pollution, porcelain creepage, oil specification, grounding, and surge protection.
- Verify support load, base width, terminal sequence, clearances, meter access, oil level, and approved drawing.
Frequently Asked Questions
Q1: Can the JLS-10 metering box operate at 4000m altitude?
Yes, it supports altitudes up to 4500m without derating. It is designed for 6kV, 10kV, 11kV, and 12kV three-phase systems. Contact us for high-altitude project verification.
Q2: What maintenance is required for the oil-immersed transformer box?
Periodic oil level checks and oil quality inspections are required. The unit uses 45# transformer oil with porcelain bushings for insulation. Refer to local electrical codes for grounding terminal connections.
Q3: Which current transformer ratios are available for this combined unit?
Standard current transformer ratios range from 5A to 300A. The voltage ratio depends on the model, such as 6000/100V for JLS-6 or 10000/100V for JLS-10. Specify your exact ratio requirements during ordering.
Q4: Are international compliance certificates available for this metering box?
It complies with the GB20840.4-2015 standard for combined transformers. For specific IEC or regional compliance certificates, please contact our sales team for details.
Q5: Do you perform factory tests prior to shipment?
Standard routine tests are conducted prior to dispatch to ensure performance. Specific type test reports and detailed test data are subject to confirmation. Request your required test documentation during the RFQ stage.
Q6: How is this combined transformer box typically installed?
It is designed for outdoor pole-mounted, substation, or distribution point installations. The unit requires proper grounding terminal connections per local electrical codes and metering standards.