Overview
The JLS-6/10 is an outdoor oil-immersed combined transformer designed for 6kV and 10kV medium-voltage distribution systems. It integrates both current transformer (CT) and voltage transformer (PT) functions in a single cast-resin insulated, oil-filled enclosure with porcelain bushings, ensuring reliable operation in harsh outdoor environments.
Built to meet GB20840.4-2015 standards, it delivers high-accuracy metering for revenue billing and protection applications. Typical use cases include pole-mounted installations, compact substations, and industrial facilities requiring precise energy measurement under varying load and temperature conditions.
Key Ratings Snapshot
| Parameter | Rating |
|---|---|
| System Voltage | 6kV / 10kV |
| Insulation Level (kV) | 3.6/25/40, 7.2/32/60, 12/42/75 |
| Primary Current Range | 5A – 300A |
| Secondary Current | 5A |
| Secondary Voltage | 100V |
| Accuracy Class (Metering) | 0.2 / 0.5 |
| Accuracy Class (Protection) | 3P / 6P |
| Insulation Medium | 45# transformer oil |
| Phase Configuration | Three-phase |
| Installation Type | Outdoor, pole-mounted or substation |
| Bushing Material | Porcelain |
| Compliance Standard | GB20840.4-2015 |
Model Designation
- J: Voltage transformer (PT)
- L: Current transformer (CT)
- S: Three-phase combined unit
- 6/10: Rated system voltage (6kV or 10kV)
Construction
The JLS-6/10 features a robust oil-immersed design with a sealed tank filled with high-quality 45# transformer oil, providing superior insulation and heat dissipation. The primary and secondary windings are housed within the oil-filled chamber, connected via porcelain bushings rated for outdoor service. The enclosure includes an oil level window for visual monitoring of oil condition and an oil drain port for maintenance. All metallic parts are corrosion-resistant, ensuring long-term reliability in standard outdoor environments. The secondary terminal box is IP-protected and provides secure connections for metering and protection circuits.
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 (domestic standard)
- 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 is a three-phase outdoor oil-immersed combined transformer designed for 6kV and 10kV systems. It features oil-immersed insulation with porcelain bushings, operates within an ambient temperature range of -15°C to +55°C, and is suitable for installations up to 4500m altitude without derating. The unit complies with GB20840.4-2015 and supports current ratios from 5A to 300A.
Voltage Transformer Data
| Voltage Ratio |
Accuracy Class |
Rated Output (VA) |
Limit Output (VA) |
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
| Current Ratio (A) |
Accuracy Class |
Rated Output (VA) |
Short-Time Thermal Current |
Dynamic Current |
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 Outdoor Oil-Immersed Combined Transformer is designed for pole-mounted or platform installation. Ensure the mounting structure can support the unit’s weight and that all clearances meet local safety regulations. Align the base dimensions (230/260/290 mm width) with the support frame, and secure using appropriate hardware. Maintain safe working distances from live parts during installation.
Wiring Diagram
Wiring connections must follow the approved project diagram and terminal markings as specified:
- AP1/AP2 and CP1/CP2 terminals correspond to the primary and secondary connections of the current transformers (CTs); verify sequence before commissioning.
- PT secondary terminals supply voltage signals to energy meters and monitoring equipment.
- CT secondary terminals deliver current signals to active and reactive energy meters.
- All secondary circuits must be properly grounded, and CT secondaries must never be left open-circuited during operation.
- Meter box wiring and grounding must comply with the project-specific wiring diagram and local utility requirements.
Selection & FAQs
Selection Guide
- Select the 6kV or 10kV model, insulation level, system frequency, and three-phase metering connection.
- Specify the PT ratio and output, then select the 5–300/5A CT ratio from expected load current.
- Choose CT class 0.2S/0.2 and PT class 0.2/0.5 and calculate all secondary burdens.
- Confirm altitude, temperature, pollution, porcelain creepage, oil specification, grounding, and surge protection.
- Verify pole or platform dimensions, line clearances, terminal sequence, oil access, lifting, and approved drawing.
Frequently Asked Questions
Q1: What is the maximum altitude for this combined transformer?
It operates up to 4500m without requiring any derating. Designed specifically for 6kV and 10kV outdoor systems. Contact us for higher altitude project verification.
Q2: How should the grounding terminal be connected during installation?
Connect the grounding terminal strictly per local electrical codes and metering standards. The unit requires periodic oil level and quality checks. Consult local regulations for specific grounding practices.
Q3: Which accuracy class is available for the voltage transformer?
Available in 0.2 and 0.5 accuracy classes depending on the voltage ratio. The 3000/100 ratio offers 0.2 class, while 6000/100 provides 0.5 class. Specify your exact ratio needs for factory selection.
Q4: Are there specific temperature limits for outdoor installation?
Yes, the ambient temperature range is strictly -15°C to +55°C. The unit uses 45# transformer oil and porcelain bushings for reliable insulation. Request the full thermal test report for your project records.
Q5: Can the current ratio be customized for specific projects?
Yes, it supports standard current ratios from 5A to 300A. Custom ratios outside this range are subject to factory confirmation. Please provide your exact primary and secondary current requirements for a technical review.
Q6: Where is this outdoor combined transformer typically installed?
It is designed for outdoor pole-mounted, substation, or distribution point installations. The JLS-6/10 handles 6kV and 10kV systems effectively. Contact our engineering team for site-specific application advice.