Overview
The LBZW-10 is an outdoor epoxy cast-resin current transformer designed for 11kV and 12kV class medium-voltage distribution systems. It features a fully insulated dry-type construction using outdoor-grade epoxy resin, eliminating the need for oil insulation and offering reliable performance in exposed environments subject to rain, humidity, dust, UV radiation, and temperature fluctuations.
This CT supports secondary outputs of 5A or 1A and offers standard accuracy combinations including 0.2/10P, 0.2S/10P, and 0.5/10P, making it suitable for both precision energy metering and relay protection. Typical applications include overhead line monitoring, pole-mounted metering units, outdoor switchgear, compact substations, and feeder protection circuits in compliance with IEC-oriented insulation levels of 12/42/75kV.
Key Ratings Snapshot
| Parameter | Rating |
|---|---|
| Voltage class | 11kV / 12kV |
| Rated insulation level | 12/42/75kV |
| Rated frequency | 50Hz (60Hz by confirmation) |
| Primary current range | 5A to 600A |
| Secondary current | 5A or 1A |
| Accuracy classes | 0.2, 0.2S, 0.5 (metering); 10P (protection) |
| Insulation type | Epoxy cast-resin, dry-type |
| Installation environment | Outdoor |
| Application functions | Current measurement, energy metering, relay protection |
Construction
The LBZW-10 features an outdoor epoxy cast-resin structure with two high-voltage bushing terminals mounted on the top for primary conductor connection. The entire body is encapsulated in weather-resistant epoxy resin, providing robust insulation without oil, thereby eliminating leakage risks and reducing maintenance needs. A sealed secondary terminal box is located on the lower side of the unit, protecting wiring connections from environmental exposure and ensuring safe field installation and servicing. This dry-type design is specifically engineered for long-term reliability in outdoor distribution applications where exposure to moisture, dust, and temperature extremes is expected.
Technical Parameters
Service Conditions
- Installation location: outdoor medium-voltage distribution equipment
- Rated voltage: 11kV and 12kV class systems by project confirmation
- Rated frequency: 50Hz; 60Hz by agreement
- Ambient temperature: -5°C to +55°C reference range
- Installation environment: should avoid continuous immersion, severe mechanical vibration and highly corrosive chemical environments unless specially specified.
- Special environmental conditions: for coastal, high-humidity, high-altitude or heavy-pollution projects, creepage distance, sealing level and insulation coordination should be confirmed before ordering.
Technical Data
The LBZW-10 is an outdoor epoxy cast-resin current transformer designed for 11kV and 12kV class medium-voltage distribution systems. It operates within an ambient temperature range of -5°C to +55°C and complies with IEC 61869-1, IEC 61869-2, GB/T 20840.1, and GB/T 20840.2 standards. The unit supports primary currents from 5A to 600A, with secondary outputs of 1A or 5A, and is suitable for both metering and protection applications.
| Current Ratio (A) |
Accuracy Classes |
Rated Output (VA) | Short-Time Thermal Current (kA/1s) |
Rated Dynamic Current (kA) |
|||
|---|---|---|---|---|---|---|---|
| 0.2S | 0.2/0.5 | 5P | 10P | ||||
| 5–400 | 0.2/10P 0.2S/10P 0.5/10P |
10 | 10 | 15 | 15 | 60 I1n | 150 I1n |
| 600 | 50 I1n | 120 I1n | |||||
Installation & Wiring
Installation Diagram
The LBZW-10 outdoor epoxy cast-resin current transformer is designed for secure mounting on a stable outdoor platform or support frame. Ensure proper alignment of primary terminals, base mounting holes, and secondary cable outlet as shown in the diagram. Maintain adequate creepage clearance and provide sufficient space for maintenance access.
Windings & Terminal Marking
| Terminal | Function | Application Note |
|---|---|---|
| P1 / P2 | Primary terminals | Outdoor high-voltage primary connection; used for current direction and polarity reference. |
| 1S1 / 1S2 | First secondary winding | Usually used for metering or measurement circuit. |
| 2S1 / 2S2 | Second secondary winding | Usually used for protection relay circuit when a protection core is specified. |
| Grounding point | Protective grounding | One point of the secondary circuit should be grounded according to project practice. |
Selection & FAQs
Selection Guide
- Confirm the 11kV or 12kV system class, 12/42/75kV insulation level, and 50Hz or 60Hz frequency.
- Select the 5A–600A primary ratio from the feeder load and choose a 1A or 5A secondary for the connected devices and cable length.
- Define metering and protection windings separately, including accuracy class and rated burden for each.
- Verify short-time thermal and dynamic current capability against the network fault level.
- Confirm platform dimensions, terminal orientation, creepage clearance, grounding, and any coastal or heavy-pollution requirements.
Frequently Asked Questions
Q1: Can the LBZW-10 CT be used on 11kV outdoor systems?
Yes, it is designed for 11kV and 12kV outdoor medium-voltage distribution. Ensure the installation environment avoids continuous immersion and severe mechanical vibration.
Q2: Which accuracy classes are available for metering and protection?
The unit supports various accuracy classes suitable for both metering and protection applications. Exact classes and rated outputs depend on the specific current ratio selected.
Q3: What are the ambient temperature limits for outdoor installation?
The standard reference ambient temperature range is -5°C to +55°C. For high-altitude or heavy-pollution projects, insulation coordination must be confirmed before ordering.
Q4: What international standards does this epoxy cast-resin CT comply with?
It complies with IEC 61869-1, IEC 61869-2, GB/T 20840.1, and GB/T 20840.2 standards. Contact us for specific test certificates and compliance documents.
Q5: How do we order custom ratios for coastal environments?
Primary currents range from 5A to 600A with 1A or 5A secondary outputs. For coastal or high-humidity sites, specify required creepage distances and sealing levels.
Q6: What is the short-time thermal current rating for this CT?
The short-time thermal current rating varies based on the selected current ratio and accuracy class. Please refer to the technical data table or contact for specific kA/1s values.
Q7: Is this manufacturer’s CT suitable for medium-voltage distribution equipment?
Yes, the LBZW-10 is an outdoor epoxy cast-resin current transformer for medium-voltage distribution. It operates at 50Hz or 60Hz by agreement.