Overview
The JLSY-35 is an outdoor oil-immersed combined transformer metering box rated for 33kV and 35kV high-voltage power systems. It integrates current transformers (CT), voltage transformers (PT), and a meter box into a single oil-filled assembly, using high-quality transformer oil for insulation and cooling.
Designed for accurate active and reactive energy measurement, it supports utility billing, industrial power monitoring, and anti-theft applications. The unit complies with GB20840.4-2015 and IEC 61869.4:2013 standards and features a three-phase three-component configuration with star-connected PTs for balanced phase performance.
Key Ratings Snapshot
| Parameter | Rating |
|---|---|
| Voltage Class | 33kV / 35kV |
| Insulation Type | Oil-immersed |
| Current Range | 5A – 800A |
| Accuracy Class (CT) | 0.2S / 0.2 / 0.5 |
| Accuracy Class (PT) | 0.2 / 0.5 |
| Phase Configuration | Three-phase three-component |
| PT Connection | Star-connected |
| Meter Box Type | Integrated (active & reactive) |
| Ambient Temperature | -25°C to +55°C |
| Compliance | GB20840.4-2015, IEC 61869.4:2013 |
| Mounting | Outdoor pole or platform |
| Bushing Type | Porcelain |
Model Designation
- J: Current and voltage combined transformer
- L: Outdoor type
- S: Three-phase
- Y: Oil-immersed insulation
- 35: Rated voltage class (35kV)
Construction
The JLSY-35 features a robust oil-immersed construction with a sealed tank filled with high-grade transformer oil, providing both electrical insulation and efficient heat dissipation. The core components—three current transformers and three star-connected voltage transformers—are housed together in a single enclosure, minimizing external connections and reducing installation complexity. Porcelain bushings are used for high-voltage terminals, ensuring reliable insulation and weather resistance in outdoor environments. The integrated meter box is mounted directly on the transformer tank and is designed to accommodate standard three-phase active and reactive energy meters or combined electronic meters. The overall structure is built for durability in harsh conditions, with corrosion-resistant materials and secure sealing to prevent moisture ingress.
Technical Parameters
Service Conditions
- Installation position: Outdoor substation or distribution points on transformer high-voltage side
- Ambient temperature: -25°C to +55°C
- Maximum altitude: ≤ 4500m (no derating required)
- Insulation: Oil-immersed with porcelain bushings
- Oil type: High-quality 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-35 is an outdoor oil-immersed combined transformer metering box designed for 33kV and 35kV systems, featuring a three-phase three-component configuration. It operates within a temperature range of -25°C to +55°C and at altitudes up to 4500m without derating. The unit complies with GB20840.4-2015 and IEC 61869.4:2013 standards and supports current ranges from 5A to 800A.
Model Variants
| Model | Configuration | Weight | Application |
|---|---|---|---|
| JLSY3-35 | Three-column type | 320 kg | Standard high-voltage metering |
| JLSY6-35 | Six-column type | 346 kg | Enhanced precision metering |
Voltage Transformer Data
| Rated Voltage (kV) |
Insulation Level (kV) |
Accuracy Class |
Rated Output (VA) |
Max Output (VA) |
|---|---|---|---|---|
| 35/0.1 | 40.5/95/185 | 0.2 | 20 | 600 |
| 33/0.1 | 40.5/95/185 | 0.5 | 30 | |
| 33/0.11 | 40.5/95/185 | 0.5 | 30 |
Current Transformer Data
| Current Ratio (A) |
Insulation Level (kV) |
Accuracy Class |
Rated Output (VA) |
Short-Time Thermal Current |
Dynamic Current |
|---|---|---|---|---|---|
| 5 – 600 | 40.5/95/185 | 0.2S | 3×15 | 80 × I1n | 200 × I1n |
| 750 – 800 | 40.5/95/185 | 0.2S | 3×20 | 80 kA | 200 kA |
Installation & Wiring
Installation Diagram
The JLSY-35 oil-immersed combined transformer metering box is designed for pole-mounted or platform installation on the high-voltage side of distribution transformers. Ensure proper alignment with insulator mounting points as specified by model type (three-column or six-column configuration) and maintain safe clearances per local electrical codes.
Wiring Diagram
Wiring connections must follow the approved project diagram and terminal markings:
- High-voltage terminals are labeled AP1/AP2, BP1/BP2, and CP1/CP2 for phases A, B, and C respectively—verify sequence before energizing.
- PT secondary terminals supply voltage signals to meters and monitoring equipment.
- CT secondary terminals deliver current signals to active and reactive energy meters.
- All secondary circuits must be connected to burden devices; CT secondaries must never be left open-circuited during operation.
- Grounding conductors and meter box wiring must comply with the project-specific wiring diagram and applicable standards.
Selection & FAQs
Selection Guide
- Select the 33kV or 35kV voltage ratio and verify the star-connected three-phase metering scheme.
- Choose the 5A–800A CT ratio from load current and select the three-column or six-column variant.
- Specify CT and PT accuracy, rated output, meter type, anti-tamper features, and secondary burdens.
- Confirm altitude, temperature, pollution, porcelain creepage, oil, grounding, lightning, and site conditions.
- Verify the 320kg or 346kg support load, clearances, terminals, oil access, lifting, and approved drawing.
Frequently Asked Questions
Q1: Can the JLSY-35 metering box operate at high altitudes?
It operates up to 4500m without derating. Designed for 33kV and 35kV outdoor systems. Confirm specific altitude requirements with our engineering team.
Q2: How should the grounding terminal be connected during installation?
Connect the grounding terminal strictly per local electrical codes and metering standards. The unit features oil-immersed insulation with porcelain bushings. Ensure proper grounding for optimal safety and performance.
Q3: Which model variant provides enhanced precision for high-voltage metering?
The JLSY6-35 six-column type is designed for enhanced precision metering. It weighs 346 kg and supports 5A to 800A current ranges. Request detailed accuracy class data from our sales team.
Q4: What international standards does this combined transformer comply with?
It complies with GB20840.4-2015 and IEC 61869.4:2013 standards. Suitable for 33kV and 35kV three-phase systems. Contact us for specific compliance certificates for your region.
Q5: Are periodic oil inspections required for this combined transformer?
Yes, periodic oil level checks and oil quality inspections are required. It uses high-quality transformer oil. Contact our service team for detailed maintenance schedules.
Q6: Where can this 35kV combined transformer metering box be installed?
It is specifically designed for outdoor substations and high-voltage side distribution points. It withstands ambient temperatures from -25°C to +55°C. Verify site conditions with our technical support.