Overview
The JLS-10, JLS-11, JLS-12 is a three-phase four-wire oil-immersed combined transformer metering box rated for 10kV, 11kV, and 12kV medium-voltage distribution systems. It integrates current transformers (CT), voltage transformers (PT), and a watt-hour meter box into a single sealed assembly filled with 25# transformer oil for insulation and cooling.
This unit delivers high-accuracy energy measurement suitable for utility revenue metering, industrial substations, and outdoor distribution networks. It complies with GB17201 standards and features an anti-theft design to protect billing integrity. The integrated construction reduces installation complexity while ensuring reliable performance in harsh outdoor environments.
Key Ratings Snapshot
| Parameter | Rating |
|---|---|
| Voltage Class | 10kV / 11kV / 12kV |
| System Type | Three-phase four-wire |
| Insulation Medium | 25# transformer oil |
| CT Accuracy Class | 0.2S / 0.5S |
| PT Accuracy Class | 0.2 / 0.5 |
| Rated Frequency | 50 Hz |
| Primary Voltage (PT) | 10 / √3 kV, 11 / √3 kV, 12 / √3 kV |
| Secondary Voltage (PT) | 100 / √3 V |
| Secondary Current (CT) | 5 A or 1 A |
| Metering Type | Active & reactive energy |
| Installation Environment | Outdoor |
| Compliance Standard | GB17201 |
Model Designation
- J: Combined instrument transformer (CT + PT)
- L: Outdoor (pole-mounted) application
- S: Three-phase four-wire system
- 10/11/12: Rated system voltage in kV
Construction
The JLS-10/11/12 features a robust cast-resin and metal housing fully immersed in 25# transformer oil, providing superior dielectric strength and thermal stability. Primary and secondary connections are made through high-quality porcelain bushings, ensuring reliable performance under outdoor conditions including rain, dust, and temperature fluctuations. The internal CT and PT cores are precisely wound and sealed within the oil-filled tank to prevent moisture ingress. An integrated watt-hour meter compartment houses both active and reactive energy meters, accessible via a secure, tamper-resistant door. The entire assembly is designed for pole or substation mounting, with lifting lugs and mounting brackets included for ease of installation.
Technical Parameters
Service Conditions
- Installation position: Outdoor pole-mounted, substation, or distribution points
- Ambient temperature: -25°C to +40°C
- Rated frequency: 50Hz or 60Hz
- Pollution class: IV level
- Insulation: Oil-immersed with 25# transformer oil
- Grounding: Connect grounding terminal per local electrical codes
- Maintenance: Periodic oil level check and meter calibration required
Technical Parameters
The JLS-10/11/12 is an outdoor oil-immersed combined transformer metering box designed for 10kV, 11kV, and 12kV three-phase four-wire systems. It features oil-immersed insulation using 25# transformer oil, operates within -25°C to +40°C ambient temperature, and complies with GB17201 standards. The unit supports current ratios from 5–300/5 A and includes integrated voltage and current transformers for accurate metering.
Model Variants
| Model | System Voltage |
Voltage Ratio |
Insulation Level (kV) |
Application |
|---|---|---|---|---|
| JLS-10 | 10kV | 10000/100V | 12/42/75 | Chinese standard 10kV systems |
| JLS-11 | 11kV | 11000/110V or 11000/100V | 12/42/75 | International 11kV systems |
| JLS-12 | 12kV | 12000/100V | 12/42/75 | International 12kV systems |
Voltage Transformer Data
| Accuracy Class | Rated Output (VA) | Application |
|---|---|---|
| 0.2 | 50 VA | High-precision metering |
| 0.5 | 25 VA | Standard metering |
Current Transformer Data
| Current Ratio | Accuracy Class | Rated Output |
|---|---|---|
| 5 – 300/5A | 0.2S | 10 VA |
| 5 – 300/5A | 0.5S | 10 VA |
Installation & Wiring
Installation Diagram
The JLS-10/11/12 oil-immersed combined transformer metering box is designed for pole-mounted or pad-mounted installation. Ensure adequate clearance and secure mounting according to local utility requirements.
Wiring Diagram
Connect primary terminals (AP1, AP2, CP1, CP2) to the high-voltage lines as indicated in the wiring diagram. Secondary terminals must be connected to the corresponding inputs in the side-mounted meter compartment, which houses active and reactive energy meters. Verify terminal markings match the specified voltage and current ratios before energizing the unit.
Selection & FAQs
Selection Guide
- Select the 10kV, 11kV, or 12kV model and confirm the three-phase four-wire metering scheme.
- Specify the PT ratio and secondary voltage, then select the 5–300/5A CT ratio from the load profile.
- Choose CT class 0.2S/0.5S and PT class 0.2/0.5 and calculate each secondary burden.
- Confirm active and reactive meters, meter-compartment layout, sealing, anti-tamper, and calibration requirements.
- Verify mounting, bushings, clearances, oil level, grounding, terminal sequence, pollution, and outdoor conditions.
Frequently Asked Questions
Q1: Can the JLS-11 model be used in 10kV networks?
Yes, subject to system confirmation. The JLS-11 is designed for 11kV systems with 12/42/75kV insulation. Consult engineering for voltage ratio adjustments.
Q2: How to install this combined transformer in high pollution areas?
It is suitable for Pollution Class IV environments. Ensure outdoor pole-mounted installation and connect the grounding terminal per local electrical codes. Contact us for site-specific mounting brackets.
Q3: What current ratio options are available for revenue metering?
The unit supports current ratios ranging from 5/5A to 300/5A. It integrates voltage and current transformers for accurate three-phase four-wire metering. Specify your exact ratio requirements during ordering.
Q4: Are custom voltage ratios available for international projects?
Yes, subject to factory confirmation. Standard models include 10000/100V and 11000/100V. Please provide your specific system voltage and ratio requirements for technical evaluation.
Q5: Which design standards govern the manufacturing of this transformer?
The JLS series is manufactured in compliance with GB17201 standards. For projects requiring IEC or ANSI certifications, availability is subject to confirmation. Contact us with your project specifications.
Q6: Where is this three-phase combined transformer metering box applied?
It is applied in outdoor substations and distribution points for 10kV to 12kV systems. The oil-immersed design ensures reliable performance in ambient temperatures from -25°C to +40°C.
Q7: When should the transformer oil level be checked?
Periodic oil level checks and meter calibrations are required. The unit uses 25# transformer oil for optimal insulation. Refer to the operation manual for exact maintenance intervals.