Overview
The LQZJ-10 is an indoor, single-phase, epoxy resin cast, fully enclosed post-type current transformer designed for 10kV–12kV medium-voltage systems. It features a coiled primary winding and is rated for IEC 12kV-class insulation coordination, making it suitable for 10kV, 11kV, and 12kV applications.
This CT supports current measurement, electric energy metering, feeder monitoring, and relay protection in 50Hz or 60Hz AC systems. It complies with IEC 61869-1 and IEC 61869-2 standards and is engineered for reliable performance in air-insulated switchgear, metering cabinets, and distribution panels.
Key Ratings Snapshot
| Parameter | Rating |
|---|---|
| Voltage class | 10kV, 11kV, 12kV |
| Highest voltage for equipment | 12kV |
| Rated insulation level | 12/42/75kV |
| Rated frequency | 50Hz / 60Hz |
| Rated secondary current | 5A or 1A |
| Primary structure | Coiled type |
| Insulation material | Epoxy resin cast |
| Application | Measurement, metering, protection, monitoring |
| Installation | Indoor switchgear and panels |
| Standards | IEC 61869-1, IEC 61869-2 |
Model Designation
- L: Current transformer
- Q: Coiled type / coil-wound primary structure
- Z: Cast-resin insulation
- J: Enhanced type / reinforced design configuration
- 10: Voltage class identification; applicable to 10kV systems and IEC 12kV-class insulation coordination for 10kV, 11kV, and 12kV projects
Construction
The LQZJ-10 features a fully enclosed post-type structure with the coiled primary winding, secondary winding, and magnetic core completely encapsulated in epoxy resin. This cast-resin construction delivers high insulation strength, excellent moisture resistance, and robust anti-pollution performance. The compact, lightweight body allows flexible mounting in indoor medium-voltage switchgear, metering panels, and distribution cabinets. All live parts are sealed within the resin matrix, ensuring long-term reliability and minimal maintenance in standard indoor environments.
Technical Parameters
Service Conditions
- Installation location: indoor medium-voltage switchgear
- System voltage: 10kV, 11kV, or 12kV class
- Rated frequency: 50Hz / 60Hz
- Rated insulation level: 12/42/75kV
- Altitude: not over 1000m under standard service conditions unless otherwise specified
- Ambient temperature: -5°C to +40°C
- Installation environment: should be free from severe vibration, corrosive gas, explosive medium, heavy pollution, and abnormal condensation.
Technical Parameters
The LQZJ-10 is a coiled-type epoxy resin cast current transformer designed for 10kV–12kV medium-voltage systems. It features cast-resin insulation, operates within an ambient temperature range of -5°C to +40°C, and is suitable for installations up to 1000m altitude. Compliant with IEC 61869-1/-2 standards, it supports primary currents from 5A to 600A with configurable secondary outputs and accuracy classes for both metering and protection applications.
| Rated Primary Current (A) |
Accuracy Classes Combination |
Rated Output (VA) | Rated Short-Time Thermal Current (kA) |
Rated Dynamic Current (kA) |
||
|---|---|---|---|---|---|---|
| 0.2 | 0.5 | 5P10 | ||||
| 50, 75 | 0.2/5P10 0.5/5P10 |
10 | 10 | 10 | 6 | 15 |
| 100 | 15 | 37.5 | ||||
| 150 | 20.5 | 56 | ||||
| 200~400 | 30 | 75 | ||||
| 600~1200 | 15 | 15 | 15 | 48 | 120 | |
Installation & Wiring
Installation Diagram
The LQZJ-10 current transformer is designed for secure mounting within indoor switchgear assemblies. Installation must follow the approved outline drawing to ensure correct primary terminal orientation, secondary terminal accessibility, and compliance with required electrical clearances and mechanical support.
Selection & FAQs
Selection Guide
- Select LQZJ-10 where a fully enclosed post-type structure is required. Unlike a semi-enclosed CT, its primary winding, secondary winding and core are encapsulated; still confirm pollution, condensation and altitude conditions.
- Choose the 5A–600A primary ratio from the actual load profile. The wound primary is particularly suited to low-current ratios, while 1A or 5A secondary selection should reflect lead length and connected equipment.
- Define both core functions and outputs. Options include 0.2/0.5, 0.5/0.5, 0.2/10P and 0.5/10P. State the accuracy class, rated output and terminal assignment of every winding.
- Complete the protection specification and resolve output differences. “10P” needs an accuracy limit factor, and the page’s 10/15VA general data versus a 15/20VA high-current row requires ratio-specific confirmation.
- Confirm fault, dielectric and dimensional data. Obtain the short-time thermal and dynamic ratings, partial-discharge limit, 12/42/75kV insulation, primary-terminal spacing, base mounting and secondary-cover clearance.
Frequently Asked Questions
Q1: What is the maximum altitude for standard installation?
Standard service conditions limit installation to a maximum altitude of 1000m. For higher elevations, derating factors apply. Contact our engineering team for altitude-specific specifications.
Q2: How to determine the required short-time thermal current rating?
The rated short-time thermal current must match your switchgear’s fault level. Refer to the technical parameter table for specific kA ratings based on primary current. Ensure proper coordination with your protection relays.
Q3: Are there specific environmental restrictions for indoor installation?
The environment must be free from severe vibration, corrosive gases, explosive mediums, heavy pollution, and abnormal condensation. Verify your switchgear room meets these criteria. Contact us if your site has abnormal conditions.
Q4: Can the secondary accuracy classes and outputs be customized?
Yes, the LQZJ-10 supports configurable secondary outputs and accuracy class combinations like 0.2, 0.5, and 5P10. Specify your exact metering and protection requirements. Contact our team to configure your order.
Q5: Which international standards does this cast-resin current transformer comply with?
This transformer is fully compliant with IEC 61869-1 and IEC 61869-2 standards. It ensures reliable performance for both metering and protection applications. Verify these standards match your local grid codes.
Q6: Where should this single-phase current transformer be installed?
It is specifically designed for indoor medium-voltage switchgear operating at 10kV, 11kV, or 12kV system voltages. It features coiled-type epoxy resin cast insulation. Confirm your switchgear dimensions with our engineering team before purchase.