Overview
The LZX-10 Series is an indoor epoxy cast-resin current transformer designed for 11kV and 12kV class medium-voltage switchgear. It features a compact, solid-body construction using flame-retardant epoxy resin, providing reliable insulation and mechanical stability for indoor applications.
This series supports both measurement and protection functions, with accuracy classes including 0.2S, 0.2, 0.5 for metering and 5P or 10P for relay protection. It is suitable for AC systems at 50Hz (60Hz available on request) and complies with international standards for use in feeder monitoring, energy metering, and protective relaying within compact indoor switchgear panels.
Key Ratings Snapshot
| Parameter | Rating |
|---|---|
| Voltage class | 11kV / 12kV |
| Insulation level | 12/42/75kV |
| Rated frequency | 50Hz (60Hz by confirmation) |
| Secondary current | 5A or 1A |
| Primary current range | 5A to 1000A |
| Metering accuracy | 0.2S, 0.2, 0.5 |
| Protection accuracy | 5P, 10P |
| Application | Measurement, metering, protection, monitoring |
| Installation type | Indoor fixed mounting |
| Insulation material | Epoxy cast-resin |
| Structure | Compact body with top primary terminals and bottom secondary terminal block |
| System compatibility | IEC-oriented 12kV equipment-class projects |
Model Designation
- L: Current transformer
- Z: Cast-resin insulation / epoxy casting structure reference
- X: Structural series code for this compact indoor CT family
- 10: Catalogue voltage-class reference; documented internationally for 11kV / 12kV class projects by insulation confirmation
- Q: Reinforced or variant structure reference, depending on drawing and factory designation
- 4 / 5: Design variant or structural sequence reference for LZX4-10 and LZX5-10
Construction
The LZX-10 Series features an indoor epoxy cast-resin structure with a compact molded body that integrates primary terminals on the top side and a secondary terminal block at the lower side. The epoxy resin provides high dielectric strength, moisture resistance, and mechanical robustness suitable for indoor environments. This construction ensures stable performance under normal operating conditions and supports practical wiring access in space-constrained switchgear panels. The design is optimized for fixed installation in standard indoor distribution cabinets where coordination of primary connections, secondary wiring, and panel clearance is essential.
Technical Parameters
Service Conditions
- Installation location: indoor medium-voltage switchgear
- System voltage: 10kV class networks
- Rated frequency: 50Hz
- Ambient temperature: -5°C to +40°C
- Installation environment: should be free from severe vibration, conductive dust, corrosive gas, explosive medium, heavy pollution and abnormal condensation.
Technical Parameters
The LZX-10Q is an indoor epoxy cast-resin current transformer designed for 10kV class systems. It features epoxy resin insulation and complies with IEC and GB standards. Primary current ranges from 5A to 1000A.
| Rated primary current (A) |
Accuracy classed combination |
Rated Output (VA) |
Short-time thermal current (kA/1s) |
Rated dynamic current (kA) |
|||
|---|---|---|---|---|---|---|---|
| 0.2S | 0.2/0.5S | 0.5 | 5P | ||||
| 5~100 | 0.5/10P15 0.2/10P15 |
10 | 10 | 15 | 15 | 90×I1n | 225×I1n |
| 150, 200 | 90×I1n | 160×I1n | |||||
| 300 | 80×I1n | 160×I1n | |||||
| 400, 500 | 75×I1n | 160×I1n | |||||
| 600, 800, 1000 | 50×I1n | 90×I1n | |||||
Installation & Wiring
Installation Diagram
The LZX-10Q series is designed for secure mounting within compact indoor switchgear. Installation must follow the approved dimensional and wiring drawings to ensure correct primary terminal spacing, base mounting alignment, secondary terminal accessibility, and adequate phase-to-ground clearance.
Selection & FAQs
Selection Guide
- Select LZX-10, LZX-10Q, LZX4-10 or LZX5-10 only after matching the exact outline, mounting base and primary-terminal drawing.
- Choose a 5A–1000A ratio from maximum load, normal metering range and prospective fault current.
- Specify 1A or 5A and order independent 0.2S/0.2/0.5 measurement and 5P/10P protection cores where both functions are needed.
- Verify 10VA measurement and 15VA protection references against calculated burden and the required protection ALF.
- Convert the listed Ith/Idyn multiples into amperes for the selected ratio, then check 12/42/75kV insulation, clearances and +55°C duty.
Frequently Asked Questions
Q1: What are the installation environment requirements for this indoor current transformer?
Install in clean, indoor switchgear free from severe vibration, conductive dust, and corrosive gases. Ambient temperature must remain between -5°C and +40°C. Contact us for specialized environmental solutions.
Q2: How is the short-time thermal current calculated for higher primary ratings?
For primary currents of 600A to 1000A, the short-time thermal current is 50×I1n kA/1s. The rated dynamic current is correspondingly 160×I1n kA. These parameters ensure safe operation during fault conditions.
Q3: Which accuracy class combination is suitable for both metering and protection?
The 0.2/10P15 or 0.5/10P15 combinations serve both functions effectively. They provide 10VA or 15VA rated outputs for protection cores. Confirm your exact burden requirements during order placement.
Q4: Does this epoxy cast-resin CT comply with international IEC standards?
Yes, the LZX-10Q complies with both IEC and GB standards. It features robust epoxy resin insulation for 10kV class networks. Request the specific type test report for your project.
Q5: Can the primary current be customized outside the standard 5A to 1000A range?
Standard ratings cover 5A to 1000A. Custom primary currents outside this range are subject to factory confirmation based on your specific switchgear dimensions. Contact our sales team for bespoke requirements.
Q6: What is the primary application for the LZX-10Q current transformer?
It is designed for current measurement and protection in 10kV class indoor medium-voltage switchgear. Operating at a rated frequency of 50Hz, it ensures reliable power distribution monitoring.
Q7: Is this 10kV current transformer compatible with 60Hz power systems?
The standard LZX-10Q is rated for 50Hz networks. Application in 60Hz systems requires specific design adjustments and factory confirmation. Please specify your system frequency when inquiring.