Product Overview

The JLS-6/10/11 combined transformer is an outdoor oil-immersed three-phase measurement device designed for 6kV, 10kV, 11kV, and 12kV medium-voltage distribution systems. This CT PT combined transformer integrates voltage transformer (PT) and current transformer (CT) functions in a single oil-immersed assembly with porcelain bushings, providing accurate current and voltage signals for energy metering and protection applications in outdoor substations and distribution networks.

Featuring oil-immersed insulation with high-quality 45# transformer oil, the JLS series delivers excellent heat dissipation and insulation performance in demanding outdoor environments. The compact three-column design with porcelain bushings ensures reliable operation across multiple voltage classes (3.6/25/40kV, 7.2/32/60kV, 12/42/75kV). Compliant with GB20840.4-2015 standards, this transformer is suitable for rural distribution networks, industrial facilities, and utility metering applications requiring precise measurement in medium-voltage systems.

Product Display

JLS-6/10/11 Product Display
JLS-6/10/11 Product Display - Technical Specifications

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Application Position

The JLS-6/10/11 is installed outdoors on poles, in substations, or at distribution points. The oil-immersed construction with porcelain bushings provides excellent insulation and heat dissipation. The primary terminals connect to the three-phase medium-voltage circuit, while the secondary terminal box supplies voltage and current signals to active energy meters, reactive energy meters, and monitoring instruments.

Main Applications

6kV, 10kV, 11kV, and 12kV outdoor distribution networks
Rural power distribution and irrigation station metering
Industrial facilities with medium-voltage incoming supply
Compact substations with integrated CT PT measurement
High-accuracy revenue metering for utility billing
Protection relay applications requiring precise current signals
Projects requiring GB20840.4-2015 compliance

Application Case Studies

Application Scenario 1: Rural Distribution Network Metering
Rural utilities deploy the JLS-6/10/11 combined transformer in 6kV and 10kV distribution networks for revenue billing and load monitoring. The oil-immersed design provides excellent heat dissipation in outdoor environments with varying ambient temperatures. The compact three-column design simplifies pole-mounted installation while maintaining high measurement accuracy.

Application Scenario 2: Industrial Substation Metering
Industrial facilities with 10kV, 11kV, or 12kV incoming supply require accurate energy measurement for cost allocation and load monitoring. The JLS series supports current range from 5A to 300A, accommodating various load conditions. The oil-immersed construction ensures stable performance under varying load conditions and temperature fluctuations.

Application Fit

Suitable For

Outdoor 6kV, 10kV, 11kV, and 12kV metering points
Rural distribution networks and irrigation stations
Industrial facilities with medium-voltage incoming supply
Compact substations with integrated CT PT measurement
Applications requiring current range from 5A to 300A
Projects requiring GB20840.4-2015 compliance
Environments with ambient temperature -15°C to +55°C

Not Recommended For

Indoor-only compact switchgear applications
Applications requiring separate CT and PT bodies
Protection-only applications where metering accuracy is not required
High-voltage systems above 12kV (use JLS-35W model instead)
Environments requiring maintenance-free operation (oil-immersed requires periodic oil checks)

Installation 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 for 6kV, 10kV, 11kV, and 12kV systems with three-phase design. Operating temperature -15°C to +55°C, altitude up to 4500m, compliant with GB20840.4-2015. Features oil-immersed insulation, porcelain bushings, and current range from 5A to 300A.

Model Variants

Model	System Voltage	Voltage Ratio	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	Limit Output	Rated Insulation Level (kV)
3000/100	0.2	15 VA	300 VA	3.6/25/40
6000/100	0.5	30 VA		7.2/32/60
10000/100	0.5	30 VA		12/42/75

Current Transformer Data

Rated Current Ratio	Accuracy Class	Rated Output	Short-Time Thermal Current	Dynamic Current	Rated Insulation Level (kV)
5 – 300/5	0.2S	7.5 VA	80 × I1n	200 × I1n	12/42/75
5 – 300/5	0.2	10 VA	80 × I1n	200 × I1n	12/42/75

Installation & Dimensions

Dimension Reference

JLS-6/10/11 Installation Diagram

View	Key Dimensions	Application Note
Front View	Height 645±5mm; Width 530mm	Three porcelain bushings with oil level window
Side View	Base width 230/260/290mm	Profile with oil tank and drain port
Top View	Length 600mm; Width 300/260mm	Oil inlet and air release valve

Weight: Approximately 72kg

Wiring Diagram

JLS 6 JLS 10 JLS 11 Outdoor Oil Immersed Combined Transformer

Installation Guidelines

Confirm AP1/AP2 and CP1/CP2 terminal sequence before commissioning
CT secondary circuits must not be open-circuited during operation
PT secondary terminals provide voltage input to meters and monitoring devices
CT secondary terminals provide current input to active and reactive energy meters
Grounding and meter box wiring should follow the approved project wiring diagram
Check oil level through oil level window before commissioning
Ensure oil drain port is properly sealed during operation

Standards Compliance

The JLS-6/10/11 combined transformer complies with GB20840.4-2015 for combined instrument transformers. For international projects, compliance should be aligned with applicable IEC instrument transformer standards and local utility metering rules.

Selection Guide

Select by system voltage: Use JLS-6 for 6kV systems (7.2kV class insulation), JLS-10 for 10kV systems (12kV class insulation), JLS-11 for 11kV systems (12kV class insulation), or JLS-12 for 12kV systems (12kV class insulation).

Select by voltage ratio: Choose 6000/100V for JLS-6, 10000/100V for JLS-10, 11000/110V for JLS-11, or 12000/100V for JLS-12 according to network voltage and meter input requirement.

Select by current ratio: Determine CT primary current according to actual load current. Supports 5A to 300A primary current range.

Select by metering accuracy: Use 0.2S CT accuracy for high-accuracy energy metering. PT accuracy classes include 0.2 and 0.5.

Ordering Information

When ordering the JLS-6/10/11 combined transformer, please specify:

Model: JLS-6, JLS-10, JLS-11, or JLS-12
System voltage: 6kV, 10kV, 11kV, or 12kV
PT ratio: 6000/100V, 10000/100V, 11000/110V, or 12000/100V
CT primary current: 5A to 300A (specify exact value)
CT secondary current: 5A
CT accuracy class: 0.2S or 0.2
PT accuracy class: 0.2 or 0.5
Installation type: Outdoor pole-mounted
Quantity

FAQs

The JLS-6/10/11 combined transformer is an outdoor oil-immersed combined transformer used for 6kV, 10kV, 11kV, and 12kV medium-voltage metering applications. It integrates CT and PT functions in one unit with oil-immersed insulation and porcelain bushings, providing accurate current and voltage signals for energy metering and protection in outdoor substations and distribution networks.

Oil-immersed design provides excellent heat dissipation and insulation performance. The transformer oil (45#) effectively cools the internal components during high-load operation, ensuring stable performance in high ambient temperatures. The oil also provides superior insulation compared to air-insulated designs.

Oil-immersed transformers require periodic oil level checks through the oil level window and oil quality inspection. The oil drain port allows for oil replacement when needed. Porcelain bushings should be inspected for cracks or contamination. Regular maintenance ensures long-term reliability and accurate metering performance.

JLS-6 is designed for 6kV systems with 6000/100V ratio and 7.2/32/60kV insulation. JLS-10 is for 10kV systems with 10000/100V ratio and 12/42/75kV insulation. JLS-11 is for 11kV systems with 11000/110V ratio and 12/42/75kV insulation. JLS-12 is for 12kV systems with 12000/100V ratio and 12/42/75kV insulation. All models share the same current range (5-300/5A) and compact three-column design.

The JLS-6/10/11 combined transformer supports CT primary current from 5A to 300A. This range accommodates various load conditions in distribution networks without requiring multiple metering units.

The JLS-6/10/11 combined transformer complies with GB20840.4-2015 for combined instrument transformers, ensuring compatibility with Chinese standards and international requirements.

CT accuracy classes include 0.2S and 0.2. PT accuracy classes include 0.2 and 0.5. Use 0.2S for high-precision revenue metering applications.

Confirm model (JLS-6, JLS-10, JLS-11, or JLS-12), system voltage, PT ratio, CT primary current, CT secondary current, accuracy classes, installation type (outdoor pole-mounted), and quantity.

JLS-6/10/11 Oil-Immersed Combined Transformer Metering Box