Product Overview

The JLS-6 / JLS-10 combined transformer is an outdoor oil-immersed three-phase measurement device designed for 6kV and 10kV 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 high-quality 45# transformer oil for excellent insulation and heat dissipation, the JLS-6/10 supports multiple voltage class options (3.6/25/40kV, 7.2/32/60kV, 12/42/75kV) and current range from 5A to 300A. The design includes oil level window for monitoring, oil drain port for maintenance, and complies with GB20840.4-2015 standards for precision metering in demanding outdoor environments.

JLS-6/10 Product Display 2

Product Display

JLS-6/10 Product Display - Technical Specifications
JLS-6/10 Product Display - Precision Metering

Application Position

The JLS-6/10 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 oil level window allows easy monitoring of oil condition, while the oil drain port facilitates maintenance. The primary terminals connect to the three-phase 6kV or 10kV circuit, while the secondary terminal box supplies voltage and current signals to active energy meters, reactive energy meters, and monitoring instruments.

Main Applications

6kV and 10kV outdoor distribution networks requiring pole-mounted metering
Compact substations with integrated CT PT measurement
Industrial distribution systems with 6kV or 10kV incoming supply
High-accuracy revenue metering for utility billing
Protection relay applications requiring precise current signals
Outdoor metering cabinets in standard environments
Projects requiring GB20840.4-2015 compliance

Application Case Studies

Application Scenario 1: Pole-Mounted Distribution Metering
Utilities deploy the JLS-6/10 oil-immersed combined transformer on concrete poles for revenue billing and load monitoring in 6kV and 10kV distribution networks. The oil-immersed design provides excellent heat dissipation in outdoor environments with high ambient temperatures. The oil level window allows operators to monitor oil condition without opening the unit, ensuring reliable long-term operation.

Application Scenario 2: Industrial Substation Metering
Industrial facilities with 6kV or 10kV incoming supply require accurate energy measurement for cost allocation and load monitoring. The 6kV 10kV combined transformer 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 and 10kV metering points requiring pole-mounted installation
Compact substations with integrated CT PT measurement
Industrial facilities with 6kV or 10kV incoming supply
Applications requiring current range from 5A to 300A
Projects requiring GB20840.4-2015 compliance
Distribution networks requiring high-accuracy metering
Environments with high ambient temperatures requiring oil cooling

Not Recommended For

Indoor-only compact switchgear applications
Applications requiring separate CT and PT bodies
Protection-only applications where metering accuracy is not required
35kV system applications (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 (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 an outdoor oil-immersed combined transformer for 6kV and 10kV 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, oil level window, and current range from 5A to 300A.

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	1s 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 Installation Diagram

View	Key Dimensions	Application Note
Front View	Height 645±5mm; Width 410/530mm; Spacing 190±2mm	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

Wiring Diagram

JLS-6/10 Wiring Diagram

[Wiring diagram to be added]

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 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-6/10 for 6kV systems (7.2kV class insulation) or 10kV systems (12kV class insulation).

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.

Select by voltage ratio: Choose 3000/100, 6000/100, or 10000/100 according to network voltage and meter input requirement.

Ordering Information

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

Model: JLS-6/10
System voltage: 6kV or 10kV
PT ratio: 3000/100, 6000/100, or 10000/100
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 combined transformer is an outdoor oil-immersed combined transformer used for 6kV and 10kV 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 pole-mounted installations and substations.

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.

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

Use 7.2kV class for the 6kV version and 12kV class for the 10kV version. The insulation levels are 7.2/32/60kV and 12/42/75kV respectively.

The JLS-6/10 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 system voltage (6kV or 10kV), PT ratio, CT primary current, CT secondary current, accuracy classes, rated burden, installation type (outdoor pole-mounted), and quantity.

JLS-6/10 Outdoor Oil-Immersed Combined Transformer, Metering Box