Overview
The JLS-10 is a pole-mounted, oil-immersed combined transformer metering box rated for 10kV three-phase AC networks. It integrates two current transformers (CTs), two voltage transformers (PTs), and a meter box into a single oil-filled enclosure, providing reliable insulation and efficient heat dissipation in outdoor environments.
Designed for accurate energy measurement, the unit complies with GB20840.4-2015 standards and supports dual ratio configurations using the V/V-12 connection method. It is suitable for rural irrigation stations, small power stations, industrial facilities, and bidirectional metering applications where ambient temperatures range from -25°C to +40°C.
Key Ratings Snapshot
| Parameter | Rating |
|---|---|
| Voltage Class | 10kV |
| System Frequency | 50Hz |
| Insulation Medium | Transformer Oil |
| Primary Voltage (PT) | 10kV / √3 |
| Secondary Voltage (PT) | 100V / √3 |
| Primary Current (CT) | 5–300A |
| Secondary Current (CT) | 5A |
| Accuracy Class (CT) | 0.2S / 0.5S |
| Accuracy Class (PT) | 0.2 / 0.5 |
| Connection Method | V/V-12 |
| Dual Ratio Capability | Yes |
| Grounding Configuration | Secondary b-point and A.C phase CT loop grounded |
Model Designation
- J: Combined instrument transformer (CT + PT)
- L: Outdoor (pole-mounted) installation type
- S: Three-phase configuration
- 10: Rated voltage class of 10kV
Construction
The JLS-10 features a five-column design with two oil-immersed voltage transformers and two current transformers mounted on a common support plate within a sealed tank filled with insulating oil. The voltage transformers employ an outer-iron core structure using cold-rolled oriented silicon steel, while the current transformers use an inner-iron core design for enhanced magnetic performance. The front face of the tank incorporates an integrated meter box housing D86 series three-phase energy meters, complete with an observation window and lead seal holes to prevent tampering. Primary connections are made via porcelain bushings with conductive rods, and secondary terminals are externally accessible for meter wiring. The tank includes an oil drain plug for maintenance and a dedicated grounding bolt for safety compliance.
Technical Parameters
Service Conditions
- Installation position: Pole-mounted on brackets or transformer platforms
- Ambient temperature: -25°C to +40°C (daily average not exceeding +30°C)
- Maximum altitude: ≤ 4500m
- System grounding: Non-effectively grounded neutral system
- Atmospheric conditions: No severe pollution in atmosphere
- Grounding: Secondary b-point and tank grounding bolt must be reliably grounded
- Maintenance: Periodic oil level check and oil quality inspection required
Technical Parameters
The JLS-10 is a pole-mounted, oil-immersed five-column combined transformer designed for 10kV systems. It operates within an ambient temperature range of -25°C to +40°C and at altitudes up to 4500m, complying with standard GB20840.4-2015. The unit features dual-ratio capability, V/V-12 connection method, integrated meter box, and supports primary current ratios from 5–300/5 A.
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 | Accuracy Class |
Rated Output |
Short-Time Thermal Current |
Dynamic Current |
Insulation Level (kV) |
|---|---|---|---|---|---|
| 5 – 300/5A | 0.2S | 7.5 VA | 80 × I1n | 200 × I1n | 12/42/75 |
| 5 – 300/5A | 0.2 | 10 VA | 80 × I1n | 200 × I1n | 12/42/75 |
Installation & Wiring
Installation Diagram
The JLS-10 is designed for pole-mounted installation using standard mounting brackets. Ensure the unit is securely fastened to prevent movement under load or environmental stress. Use the integrated lifting lugs for safe hoisting—never lift by the bushings.
Wiring Diagram
The five-bushing layout includes terminals labeled AP1, AP2, B, CP1, and CP2. For single-ratio configurations, standard terminals are used; dual-ratio units feature AP3/CP3 terminals. In V/V-12 connection, the secondary b-point of the voltage circuit and the tail ends of the A and C phase current secondaries are internally bonded but not grounded within the box. During meter installation, this common point (b) must be externally and reliably grounded. Always verify phase sequence before energizing—swap any two high-voltage conductors if reversal is detected. For two-phase-one-ground systems, connect the ground conductor to the B-phase terminal.
Selection & FAQs
Selection Guide
- Confirm the 10kV non-effectively grounded network and verify the five-column V/V-12 metering scheme.
- Select the 5–300/5A CT ratio and determine whether a dual-ratio configuration is required.
- Specify CT and PT accuracy, rated output, meter type, and complete secondary burden.
- Confirm phase sequence, external b-point grounding, tank grounding, anti-tamper sealing, and surge protection.
- Verify pole brackets, clearances, five-bushing terminals, lifting points, oil access, and approved wiring diagram.
Frequently Asked Questions
Q1: What is the maximum altitude for installing this 10kV combined transformer?
It is designed for maximum altitudes up to 4500m. The oil-immersed five-column structure ensures reliable performance in these conditions. Please specify your exact altitude during inquiry.
Q2: Which accuracy class is available for the voltage transformer section?
The VT section offers 0.2 and 0.5 accuracy classes. Rated outputs are 15 VA and 30 VA respectively, with a 300 VA limit output. Confirm your required metering class with our sales team.
Q3: How should the secondary and tank grounding be configured?
The secondary b-point and tank grounding bolt must be reliably grounded. This applies to non-effectively grounded neutral systems. Verify grounding specifications with your site engineer before installation.
Q4: Are custom primary current ratios available for this unit?
Yes, the unit supports primary current ratios from 5 to 300/5 A. It also features dual-ratio capability for flexible applications. Contact us to confirm your specific ratio requirements and lead times.
Q5: Can you provide third-party certification and factory test reports?
Standard routine tests are conducted per GB20840.4-2015. Specific type tests or third-party certifications are subject to confirmation. Request the detailed test report checklist from your account manager.
Q6: Why choose a five-column combined transformer for 10kV pole-mounting?
It integrates both current and voltage transformation in a single oil-immersed unit. This reduces footprint and simplifies wiring for pole-mounted brackets. Ideal for standard 10kV distribution networks.
Q7: When should routine maintenance be performed on this oil-immersed unit?
Periodic oil level checks and oil quality inspections are required. The ambient operating temperature range is -25°C to +40°C. Refer to the operation manual for exact maintenance intervals.