Overview
The LZZW6-15A(B) is a pole-mounted, fully enclosed outdoor current transformer designed for 15 kV class medium-voltage distribution systems, including 13.8 kV and 15 kV networks. It features a cast-resin insulation structure engineered for reliable outdoor operation under rain, humidity, and pollution exposure.
Built to support both metering and protection functions, it delivers standard secondary currents of 5 A or 1 A with accuracy classes suitable for revenue metering and relay coordination. The unit complies with relevant IEC and IEEE standards for outdoor current transformers and is rated for continuous operation in ambient temperatures from -25°C to +55°C.
Key Ratings Snapshot
| Parameter | Rating |
|---|---|
| System voltage | 13.8 kV / 15 kV |
| Rated insulation level | 17.5/55/105 kV |
| Rated frequency | 50 Hz / 60 Hz |
| Rated secondary current | 5 A or 1 A |
| Installation type | Pole-mounted, outdoor |
| Insulation material | Cast-resin |
| Ambient temperature range | -25°C to +55°C |
| Primary connection | Pole-mounted busbar or conductor |
| Secondary terminals | Sealed outdoor-rated terminals |
| Application | Metering, protection, monitoring |
| Enclosure | Fully enclosed |
| Structure type | LZZW6-15A(B) outdoor CT family |
Model Designation
- L: Current transformer (CT)
- Z: Cast-resin insulated
- Z: Outdoor (pole-mounted) type
- W: Fully enclosed structure
- 6: Design series number
- 15: Rated system voltage class (15 kV)
- A(B): Variant indicating primary current range and terminal configuration (A and B versions)
Construction
The LZZW6-15A(B) features a fully enclosed cast-resin insulation body that encapsulates the magnetic core, primary conductor, and secondary winding. This monolithic resin structure provides high mechanical strength and excellent resistance to environmental stressors such as moisture, dust, UV radiation, and temperature cycling. All external surfaces are designed with adequate creepage distance for 15 kV outdoor service under polluted conditions. Primary terminals are integrated into the top of the housing for direct pole-mounted line connection, while secondary terminals are housed in a sealed, weatherproof compartment at the base to prevent moisture ingress. The entire assembly is mounted on a robust base compatible with standard utility poles, ensuring long-term stability and safety in exposed distribution environments.
Technical Parameters
Service Conditions
- Installation location: outdoor pole-mounted medium-voltage distribution system
- System voltage: 13.8 kV and 15 kV class networks
- Rated frequency: 50 Hz / 60 Hz
- Rated secondary current: 5 A or 1 A
- Ambient temperature: -25°C to +55°C
- Installation environment considerations: humidity, rain, pollution, wind load, altitude and mounting stability
- Special environmental confirmation required for: coastal, heavy-pollution, high-humidity or high-altitude projects (creepage distance and insulation coordination shall be confirmed separately)
Technical Parameters
The LZZW6-15A(B) is a pole-mounted, fully enclosed outdoor current transformer designed for 15 kV class systems (including 13.8 kV), with cast-resin insulation, an operating temperature range of -25°C to +55°C, and compliance with GB 20840.1-2010 and GB 20840.2-2014. It supports primary current ratings from 5 A up to 600 A, with secondary outputs of 1 A or 5 A, and offers multiple accuracy classes for metering and protection applications.
Technical Data
Single Current Ratio
| Rated Primary Current (A) |
Accuracy Classes / Rated Output (VA) | Rated Short-Time Thermal Current (kA/1s) |
Rated Dynamic Current (kA) |
|||
|---|---|---|---|---|---|---|
| 0.2S | 0.2 | 0.5S | 0.5 | |||
| 5–300 | 20 | 30 | 30 | 40 | 80 × I1n (A) | 200 × I1n (A) |
| 400 | 20 | 30 | 30 | 40 | 31.5 | 100 |
| 500 | 30 | 40 | 50 | 50 | 45 | 112.5 |
| 600 | 50 | 50 | 60 | 60 | 63 | 160 |
Compound Current Ratio
| Rated Primary Current (A) |
Accuracy Classes / Rated Output (VA) | Rated Short-Time Thermal Current (kA/1s) |
Rated Dynamic Current (kA) |
|||
|---|---|---|---|---|---|---|
| 0.2S | 0.2 | 0.5S | 0.5 | |||
| 50–100 / 100–200 150–300 / 200–400 300–600 |
10 | 15 | 20 | 20 | 80 × I1n (A) | 200 × I1n (A) |
Terminal Identification and Function
| Terminal Area | Function | Engineering Note |
|---|---|---|
| H1 / H2 | Primary side reference | Used for primary-side direction in the wiring diagram. |
| P1 / P2 | Primary polarity marking | Connect according to the line direction and approved drawing. |
| S1 / S2 | Secondary output | Connect to meter, relay or monitoring device according to polarity. |
| C1 / C2 | Tap / compound terminal reference | Used according to the specified current ratio and wiring diagram. |
Installation & Wiring
Installation Diagram
The LZZW6-15A(B) current transformer is designed for pole-mounted installation in outdoor medium-voltage distribution systems. Mounting must follow the confirmed outline drawing (15A or 15B variant) to ensure correct primary conductor alignment, secondary terminal box orientation, and cable routing. Secure the unit using a compatible mounting bracket attached to the utility pole, ensuring all hardware meets mechanical load requirements for outdoor service.
Selection & FAQs
Selection Guide
- Confirm the 13.8kV or 15kV system class, 17.5/55/105kV insulation level, frequency, and outdoor environment.
- Select the 5A–600A single or compound primary ratio from the operating current range and protection study.
- Choose a 1A or 5A secondary and specify the accuracy class and VA burden for each required function.
- Verify Ith and Idyn against the overhead network fault level and clearing time.
- Select the A or B variant from the approved drawing, pole bracket, conductor alignment, terminal arrangement, wind load, and clearances.
Frequently Asked Questions
Q1: Can the LZZW6-15A(B) be used in 13.8 kV distribution networks?
Yes, it is specifically rated for 13.8 kV and 15 kV class networks. The cast-resin insulation supports outdoor pole-mounted medium-voltage distribution. Please confirm exact system voltage during ordering.
Q2: What ambient temperature range does this outdoor current transformer support?
It operates reliably in ambient temperatures from -25°C to +55°C. The fully enclosed cast-resin design withstands humidity, rain, and pollution. For coastal or high-altitude projects, special environmental confirmation is required.
Q3: Which international standards does this pole-mounted transformer comply with?
It complies strictly with GB 20840.1-2010 and GB 20840.2-2014 standards. These govern instrument transformers for 50 Hz and 60 Hz networks. Request the specific test reports during procurement.
Q4: How do I select the secondary current and accuracy class?
Choose 5 A or 1 A for the rated secondary current based on your burden. Multiple accuracy classes are available for both metering and protection applications. Specify your exact accuracy requirements for factory configuration.
Q5: Are custom primary current ratings available for this model?
Yes, primary current ratings range continuously from 5 A up to 600 A. We support single current ratio configurations for your specific needs. Submit your exact primary current requirements for a customized quote.
Q6: Where is the LZZW6-15A(B) current transformer typically installed?
It is primarily installed in outdoor pole-mounted medium-voltage distribution systems. The fully enclosed design suits 13.8 kV and 15 kV networks exposed to weather. Verify mounting stability and wind load conditions before installation.