Overview
The LA2-10 / LAJ-10 (LFZBJ-10GY) is an indoor wall-through epoxy cast-resin current transformer designed for 11kV and 12kV class medium-voltage switchgear. It features a solid cast-resin insulated body suitable for 50Hz AC systems, with a rated insulation level of 12/42/75kV in compliance with IEC instrument transformer standards.
This CT supports both metering and protection applications, offering accuracy classes such as 0.2, 0.5, and protection class 10P10. It delivers a standardized secondary output of 5A or 1A for use in energy metering, feeder monitoring, relay protection, and current measurement circuits—commonly deployed in Southeast Asia and other international markets requiring IEC-aligned specifications.
Key Ratings Snapshot
| Parameter | Rating |
|---|---|
| Voltage class | 11kV / 12kV |
| Rated insulation level | 12/42/75kV |
| Rated frequency | 50Hz |
| Secondary current | 5A or 1A |
| Primary current range | 50A to 630A |
| Metering accuracy | 0.2, 0.5 |
| Protection class | 10P10 |
| Installation type | Indoor, wall-through |
| Insulation material | Epoxy cast-resin |
| Application | Measurement, metering, protection |
| System compatibility | IEC-based 12kV switchgear |
| Mounting | Fixed plate through cabinet partition |
Construction
The LA2-10 / LAJ-10 (LFZBJ-10GY) features a monolithic epoxy cast-resin body that fully encapsulates the magnetic core and secondary windings. This construction provides high dielectric strength, mechanical robustness, and resistance to moisture and contamination in indoor environments. The primary conductor path is integrated through the center of the unit, with extended primary terminals on both sides of the molded housing to facilitate connection across a switchgear partition. A central mounting flange allows secure fixation to the cabinet wall. The secondary terminal block is embedded directly into the resin surface, ensuring reliable and accessible connections for meters, relays, and monitoring equipment. The overall design eliminates air gaps and voids, enhancing long-term operational stability under continuous load and short-circuit conditions.
Technical Parameters
Service Conditions
- Installation location: indoor medium-voltage switchgear
- Rated voltage: 11kV and 12kV class systems by project confirmation
- Rated frequency: 50Hz
- Ambient temperature: -5°C to +55°C
- Indoor environment should be free from: explosive gas, corrosive vapor, conductive dust, heavy pollution and abnormal condensation.
- Special conditions note: For Southeast Asia projects with high humidity, coastal conditions or elevated ambient temperature, anti-condensation and creepage/clearance confirmation is recommended.
Technical Parameters
The LA2-10 and LAJ-10 (LFZBJ-10GY) wall-through cast-resin current transformers are designed for indoor use in 11kV and 12kV class medium-voltage switchgear. They feature a rated insulation level of 12/42/75kV, operate within an ambient temperature range of -5°C to +55°C, and comply with IEC 61869-2, GB20840.2-2014, and GB1208-2006 standards. The devices support primary currents from 50A to 630A, secondary outputs of 1A or 5A, and accuracy classes including 0.2, 0.5, and 10P10.
| Rated Primary Current (A) |
Accuracy Class Combination |
Rated Output (VA) | Rated Short-Time Thermal Current (kA) |
Rated Dynamic Current (kA) |
||
|---|---|---|---|---|---|---|
| 0.2 | 0.5 | 10P10 | ||||
| 50 | 0.2 0.5 10P10 |
10 | 15 | 10 | 7.5 | 19 |
| 75 | 11.25 | 28 | ||||
| 100 | 15 | 37.5 | ||||
| 150 | ||||||
| 200 | 22.5 | 56 | ||||
| 300 | 30 | 75 | ||||
| 400 | 40 | 100 | ||||
| 500 | ||||||
| 600 | ||||||
| 630 | ||||||
Installation & Wiring
Installation Diagram
The LA2-10 / LAJ-10 (LFZBJ-10GY) is installed through a partition wall in indoor switchgear. The primary terminals extend from both sides of the cast-resin body, requiring adequate clearance on either side of the wall. Mounting is achieved via a front or rear mounting plate secured to the switchgear structure. Ensure alignment with the wall opening, busbar path, and secondary terminal access as per the approved outline drawing.
Selection & FAQs
Selection Guide
- Confirm whether LA2-10, LAJ-10 or LFZBJ-10GY matches the required wall-through outline, terminals and factory designation.
- Select a 50A–630A primary ratio from load, metering range and fault study, then choose a compatible 1A or 5A secondary.
- The page shows one S1/S2 winding, so choose one class—0.2/0.5 measurement or 10P10 protection—unless an independent multi-core version is documented.
- Verify 10VA or 15VA output against the connected device and secondary-lead burden.
- Approve the 160×220mm opening, 4-Ø14 holes, 480mm overall length, busbar alignment, 12/42/75kV clearance and +55°C duty.
Frequently Asked Questions
Q1: Can the LA2-10 current transformer be applied in 11kV switchgear?
Yes, subject to project confirmation. It is rated for 11kV and 12kV indoor medium-voltage systems with 12/42/75kV insulation. Contact us for specific system voltage verification.
Q2: Which accuracy class is recommended for protective relaying?
Select the 10P10 accuracy class for protection applications. It ensures reliable performance during fault conditions per IEC 61869-2 standards. Specify your exact burden requirements during ordering.
Q3: What are the ambient temperature limits for indoor installation?
The standard operating range is -5°C to +55°C. Ensure the indoor environment is free from corrosive vapor and conductive dust. Anti-condensation measures are recommended for high-humidity regions.
Q4: How is the short-circuit thermal current rating determined?
Ratings depend on the selected primary current from 50A to 630A. Exact short-time thermal and dynamic current values are provided in the technical datasheet. Request the full specification sheet for detailed calculations.
Q5: Which international standards does this current transformer comply with?
The LAJ-10 complies with IEC 61869-2, GB20840.2-2014, and GB1208-2006. All units undergo standard factory testing before shipment. Please confirm any specific local certification requirements with our sales team.
Q6: Are 1A secondary outputs available for this model?
Yes, both 1A and 5A secondary outputs are available. Customization is subject to factory confirmation based on your specific metering or protection needs. Indicate your preferred secondary current in the inquiry.
Q7: Where should this wall-through current transformer be installed?
It is designed specifically for indoor medium-voltage switchgear applications. It suits 11kV and 12kV class distribution networks. Contact us for application-specific drawing confirmations.