Overview
The LDZ1-10 is an indoor epoxy resin cast single-turn-through current transformer designed for 10kV class AC power systems operating at 50Hz. It features a ring-core structure with the primary conductor passing through the body as a single turn, while the secondary winding and magnetic core are fully encapsulated in cast-resin insulation for enhanced dielectric strength and mechanical durability.
This transformer supports applications in current measurement, electric energy metering, and relay protection within fixed indoor switchgear and medium-voltage distribution panels. It complies with standard requirements for indoor 10kV, 11kV, and 12kV systems when project-specific conditions—including insulation level, service environment, and applicable standards—are verified during selection.
Key Ratings Snapshot
| Parameter | Rating |
|---|---|
| Rated voltage class | 10kV (applicable to 10kV, 11kV, 12kV by confirmation) |
| Rated frequency | 50Hz |
| Primary current | Single-turn-through type |
| Secondary current | 5A or 1A (as per order) |
| Insulation material | Epoxy resin casting |
| Core material | Annealed ring core |
| Installation type | Wall-through mounting |
| Application | Metering and protection |
| Accuracy class (metering) | 0.2, 0.5, 1 (as specified) |
| Accuracy class (protection) | 5P, 10P (as specified) |
| Rated burden | As per IEC/GB standards |
| Indoor use only | Yes |
Model Designation
- L: Current transformer
- D: Single-turn-through type
- Z: Epoxy resin casting insulation
- 1: Design sequence code
- 10: Rated voltage class: 10kV class
Construction
The LDZ1-10 features a robust construction based on an annealed ring-core design, ensuring low magnetic losses and high accuracy. The primary circuit is formed by a single conductor passing directly through the center of the transformer body. The secondary winding is uniformly wound around the core and fully embedded within a solid epoxy resin cast structure, which provides excellent electrical insulation, moisture resistance, and mechanical stability. The base of the cast body includes integrated mounting holes for secure wall-through installation in fixed indoor switchgear panels, along with a designated area for the rating plate and a dedicated earthing bolt for safety compliance.
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
Performance conforms with IEC standard and GB1208-87 Current Transformer. The LDZ1-10 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.
| Parameter | Rated primary current (A) | |
|---|---|---|
| 400, 600 | 800, 1000, 1200, 1500 | |
| Rated secondary current (A) | 5 | 5 |
| Frequency (Hz) | 50 | 50 |
| Rated output (VA) | 0.2: 30 | 0.2: 10 |
| 0.5: 30 | 0.5: 10 | |
| 10P15: 30 | 10P15: 15 | |
| 1s thermal current (kA) | 75×I1n | 50×I1n |
| Dynamic current (kA) | 120×I1n | 90×I1n |
| Rated insulation level (kV) | 11.5/42/75 | 11.5/42/75 |
Installation & Wiring
Installation Diagram
The LDZ1-10 current transformer is installed through a wall opening in fixed switchgear or cabinet panels. The cast-resin body is secured via mounting holes on the base, with the primary conductor passing through the central aperture as a single-turn arrangement. Ensure alignment of the wall-through hole, primary conductor path, secondary terminal access, and earthing point per the approved outline drawing prior to cabinet fabrication.
Selection & FAQs
Selection Guide
- Obtain the exact highest equipment voltage, power-frequency and impulse insulation levels because the page provides only a “10kV class” label.
- Select the project-specific ratio from continuous load, metering range and fault study, then choose 1A or 5A secondary.
- Specify each core separately for metering or 5P/10P protection, including class, FS/ALF and terminal marking.
- Calculate instrument/relay and lead burden and require a numerical VA rating plus ratio-specific thermal/dynamic withstand.
- Approve aperture, wall opening, mounting holes, conductor support, earthing bolt, ≤1000m altitude, humidity and 50Hz operation.
Frequently Asked Questions
Q1: What accuracy class is available for this 10kV current transformer?
The LDZ1-10 offers 0.2, 0.5, and 10P15 accuracy classes. Rated output varies from 10VA to 30VA depending on the primary current rating. Contact our engineers to specify your exact measurement or protection requirements.
Q2: Can this epoxy resin CT be installed outdoors or in harsh environments?
No, it is strictly designed for indoor medium-voltage switchgear. The installation environment must be free from severe vibration, conductive dust, corrosive gases, and abnormal condensation. Confirm your site conditions with our technical team before ordering.
Q3: How does it perform under short-circuit conditions for 1000A primary current?
It provides robust short-circuit withstand capability for high-current applications. For 800A to 1500A primary currents, the 1-second thermal current is 50×I1n and dynamic current is 90×I1n. Please provide your specific fault level calculations for final factory verification.
Q4: Are custom primary current ratios available for this indoor current transformer?
Yes, we support custom primary current ratios within the 400A to 1500A range. Standard secondary current is 5A at 50Hz. Submit your specific ratio and burden requirements to our sales team for a customized quote.
Q5: Which standards and factory tests apply to this epoxy cast-resin CT?
Performance conforms to IEC standards and GB1208-87 for current transformers. Standard routine tests are performed before shipment. Contact us for the detailed test report format and specific certification documents required for your project.
Q6: Which applications are suitable for the LDZ1-10 indoor current transformer?
This epoxy resin cast current transformer is ideal for 10kV class indoor medium-voltage switchgear. It operates at a rated frequency of 50Hz with ambient temperatures up to +40°C. Check with our application engineers for specific switchgear compatibility.
Q7: Why choose epoxy resin cast insulation for this 10kV class CT?
It provides durable insulation for reliable indoor performance. The rated insulation level is 11kV, suitable for 10kV class networks. Request the full technical datasheet from our manufacturer representatives for detailed dielectric parameters.