Overview
The LZW43-10/LJ-ZW32-12 Outdoor Current Transformer is a high-performance, oil-immersed current transformer engineered for direct integration with ZW43 and ZW32 vacuum circuit breakers in 10kV/12kV medium-voltage distribution networks. Designed for pole-mounted switchgear applications, it delivers accurate current measurement, reliable energy metering, and robust fault protectionâeven under severe outdoor conditions such as high humidity, salt fog, dust, and wide temperature swings.
Built with advanced silicone rubber insulation, this CT offers exceptional pollution resistance, anti-flashover capability, and wet/pollution withstand voltage up to 2.5 times higher than conventional epoxy-resin outdoor transformers. Its compact, explosion-proof design ensures long-term reliability, mechanical durability, and safety in demanding utility and industrial environments.
Key Ratings Snapshot
| Parameter | Value |
|---|---|
| System Voltage | 10kV / 12kV |
| Primary Current Range | 20A â 1200A |
| Secondary Current | 5A (standard), 1A (optional) |
| Accuracy Classes | 0.2S / 0.5S / 1 / 3 / 5P10 / 5P15 / 5P20 |
| Insulation Level (Um/Ur) | 12kV / 42kV |
| Thermal Withstand (1s) | Up to 25kA |
| Dynamic Withstand Current | Up to 63kA peak |
| Insulation Material | Silicone Rubber (high hydrophobicity) |
Construction
The LZW43-10/LJ-ZW32-12 features a compact, oil-immersed design optimized for direct mounting onto ZW43 or ZW32 vacuum circuit breakers without additional brackets. Primary terminals are clearly marked P1 (input) and P2 (output); secondary terminals are labeled S1 and S2, with S1 serving as the polarity reference for metering and protection circuits. Standard secondary output is 5A, with 1A available as an option for long-distance wiring applications.
The transformerâs core is encapsulated in high-grade insulating oil within a housing made of high-hydrophobicity silicone rubber. This material provides superior creepage resistance, excellent UV stability, and outstanding performance in wet or polluted environments. The robust mechanical structure ensures impact resistance and explosion-proof operation, significantly improving service life compared to legacy epoxy-based designs.
Technical Parameters
Service Conditions
- Altitude: <= 1000m
- Ambient Temperature Range: -40 deg C to +45 deg C
- Environment: Outdoor, suitable for high humidity, salt fog, and industrial pollution
- Installation Orientation: Vertical, mounted directly on compatible vacuum circuit breaker
Technical Data
Data Reference
| Model | Rated Primary Current (A) |
Rated Secondary Current (A) |
Accuracy Class & Rated Output (VA) |
Insulation Level (kV) |
|---|---|---|---|---|
| LZW32-10(12) LZW43-10(12) |
20 / 30 / 50 | 5 (1) | 10P10: 5 / 10 / 10 VA | 10(12)/42 |
| 50 / 100 / 150 | 5 (1) | 10P10: 10 / 15 / 15 VA | 10(12)/42 | |
| 100 / 200 / 300 | 5 (1) | 10P10: 10 / 15 / 15 VA | 10(12)/42 | |
| LZW32-10(12) LZW43-10(12) |
200 / 400 / 600 | 5 (1) | 10P10: 10 / 15 / 20 VA | 10(12)/42 |
| 600 / 1000 / 1200 | 5 (1) | 10P10: 20 / 30 / 40 VA | 10(12)/42 |
Installation & Wiring
Installation Diagram
These current transformers mount directly onto ZW43 or ZW32 vacuum circuit breakers using integrated mounting bases. Ensure primary conductors pass cleanly through the center aperture and that secondary wiring is routed away from high-voltage components. Always verify terminal polarity: P1 faces the power source, and S1 connects toward the metering or protection device.
Outline Dimensions
| Model | L (mm) | W (mm) | H (mm) | Weight (kg) |
|---|---|---|---|---|
| LZW43-10 / LJ-ZW32-12 | 120 | 120 | 280 | Approx. 8.5 |
Selection & FAQs
Selection Guide
- Confirm compatibility with the ZW43 or ZW32 breaker model, 10kV or 12kV system class, and mounting interface.
- Select the 20A–1200A primary ratio from the feeder load and protection settings, then choose a 5A or optional 1A secondary.
- Specify the required 10P10 burden for the relay circuit and verify total cable and device load.
- Check short-time thermal and dynamic withstand against the breaker fault duty.
- Confirm vertical mounting dimensions, polarity, conductor alignment, secondary routing, grounding, and outdoor pollution conditions.
Frequently Asked Questions
Q1: What are the outdoor environmental limits for this current transformer?
It operates up to 1000m altitude and -40°C to +45°C. The housing withstands high humidity, salt fog, and industrial pollution. Contact us for high-altitude project adjustments.
Q2: Which primary current ratings are available for the LZW43-12 model?
Rated primary currents range from 20A up to 1200A across multiple tap options. Secondary current is standardized at 5A or 1A. Specify your exact load requirements for factory configuration.
Q3: Why is the 10P10 accuracy class specified for this CT?
The 10P10 class ensures reliable protection during fault conditions. Rated outputs vary from 5VA to 40VA depending on the primary current selected. Confirm your specific burden requirements before ordering.
Q4: Are factory test certificates provided before shipment?
Factory testing procedures and specific test certificates are subject to confirmation. The base insulation level is rated at 12/42kV for standard models. Contact our team for detailed test reports.
Q5: How do we request a 1A secondary current option?
A 1A secondary output is available alongside the standard 5A option. Lead times and pricing for custom configurations are subject to confirmation. Contact our sales team for exact delivery schedules.
Q6: Which applications suit the LJ-ZW32-12 outdoor current transformer?
It is specifically designed for outdoor vacuum circuit breakers in 10kV and 12kV distribution networks. The vertical mounting orientation ensures direct integration with compatible switchgear. Verify mechanical dimensions with your breaker supplier.
Q7: Can this 10kV CT be used on 12kV systems?
Yes, the insulation level is rated at 12/42kV for both 10kV and 12kV models. It safely handles the dielectric stresses of 12kV outdoor switchgear. Confirm your system voltage during inquiry.