Overview
The LZJC6-10/145 / LZJC-12 is an indoor, single-phase current transformer designed for 10kV, 11kV, and 12kV medium-voltage systems. It features epoxy resin cast insulation with a fully enclosed support structure, encapsulating the primary winding, secondary winding, and annular magnetic core to ensure high dielectric strength, moisture resistance, and mechanical stability.
Built for reliable operation in compact indoor switchgear environments, it supports current measurement, energy metering, feeder monitoring, and relay protection in 50Hz or 60Hz AC systems. The grooved external surface enhances creepage performance, making it suitable for humid or polluted indoor conditions while meeting standard requirements for medium-voltage instrumentation and protection applications.
Key Ratings Snapshot
| Parameter | Rating |
|---|---|
| Voltage class | 10kV / 11kV / 12kV |
| Rated insulation level | 12/42/75kV |
| Rated frequency | 50Hz / 60Hz |
| Rated secondary current | 1A or 5A |
| Primary current range | Standard and custom ratios available |
| Core configuration | Metering, protection, or combined |
| Insulation material | Epoxy resin cast |
| Installation type | Indoor, omni-directional |
| Application | Measurement, metering, protection, monitoring |
| System compatibility | Air-insulated switchgear, distribution panels |
| External insulation | Grooved surface for enhanced creepage |
| Construction | Fully enclosed, single-phase |
Model Designation
Construction
The LZJC6-10/145 / LZJC-12 current transformer employs a monolithic epoxy resin cast construction, fully encapsulating the annular magnetic core, primary conductor, and secondary winding within a solid insulating body. This design provides excellent electrical insulation between the high-voltage primary circuit and the low-voltage secondary circuit, along with robust mechanical integrity and resistance to environmental factors such as humidity and dust. The external surface features longitudinal grooves to increase creepage distance, enhancing pollution and moisture performance in indoor switchgear applications. The compact, lightweight housing integrates current transformation, insulation, and mechanical support functions into a single unit, enabling flexible omni-directional installation in confined switchgear compartments without requiring additional mounting hardware.
Technical Parameters
Service Conditions
- Installation location: indoor medium-voltage switchgear
- System voltage: 10kV, 11kV, or 12kV class
- Rated frequency: 50Hz / 60Hz
- Highest voltage for equipment: 12kV
- Ambient temperature: -25°C to +40°C reference range, or according to project requirement
- Installation environment: should be free from severe vibration, explosive medium, corrosive gas, heavy conductive dust, and abnormal condensation.
- Special conditions: For high altitude, high humidity, coastal, heavy pollution, high temperature variation, or special cabinet conditions, technical confirmation is recommended before ordering.
Technical Parameters
The LZJC6-10/145 and LZJC-12 are 10kV–12kV epoxy resin cast current transformers designed for indoor switchgear applications. They feature fully enclosed cast-resin insulation, operate within an ambient temperature range of -25°C to +40°C (extendable per project), and comply with IEC 60044-1 or IEC 61869 standards. Rated primary currents range from 5A to 1000A with secondary options of 1A or 5A, supporting metering and protection accuracy combinations.
| Type | Rated Voltage(kV) |
Rated Primary Current(A) |
Rated Secondary Current(A) |
Accuracy
Classes |
Rated Secondary
Burden (VA) |
Accuracy LimitFactor for 10P |
Rated Short-Time ThermalCurrent Ith/1s (kA r.m.s.) |
Rated DynamicCurrent Idyn (kA Peak) |
Weight (kg) |
|
|---|---|---|---|---|---|---|---|---|---|---|
| 0.5
0.2S 0.2 |
5P
10P |
|||||||||
| LZJ-10 | 10 | 5-400 | 5 | 0.2/10P 0.2S/10P 0.5/10P |
10 | 15 | 10 | 60 I1n | 150 I1n | 14 |
| 600 | 50 I1n | 120 I1n | ||||||||
| 800 | 50 I1n | 100 I1n | ||||||||
| 1000 | 45 I1n | 90 I1n | ||||||||
| LZJD-10 LZJC-10 |
5-400 | 15 | 90 I1n | 160 I1n | ||||||
| 600 | 60 I1n | 150 I1n | ||||||||
| 800 | 50 I1n | 120 I1n | ||||||||
| 1000 | 45 I1n | 90 I1n | ||||||||
Installation & Wiring
Installation Diagram
The LZJC6-10/145 and LZJC-12 current transformers are designed for indoor switchgear installation with omni-directional mounting capability. The epoxy resin cast body enables flexible orientation within compact cabinet layouts, while the grooved external insulation enhances dielectric performance. Primary and secondary terminal positions, as well as mounting hole locations, must align with the approved outline drawing prior to switchgear fabrication.
Selection & FAQs
Selection Guide
- Confirm the exact LZJC6-10/145 or LZJC-12 outline. The “145” element is not reliably defined in the source and must not be interpreted as a voltage, burden or dimension without the manufacturer’s model code and drawing.
- Select a 5A–1000A ratio and 1A or 5A secondary. Use load and cable-burden calculations, noting that the detailed fault table is expressed for 5A secondary and any 1A configuration needs separate confirmation.
- Specify both core classes and rated outputs. Options include 0.2S/0.2S, 0.2S/0.5, 0.2S/10P and 0.5/10P, with 10VA and 15VA references that must be allocated per winding.
- Coordinate FS and ALF with the application. Choose FS 5 or FS 10 for metering-core security and ALF 10 or a project-specific value for protection; these parameters serve different purposes.
- Verify environment, orientation and fault withstand. Confirm the −25°C to +40°C range, altitude, actual creepage, partial discharge, mounting holes, terminal access, and ratio-specific thermal-current duration and dynamic current.
Frequently Asked Questions
Q1: Are these cast-resin CTs suitable for outdoor switchgear?
No, they are strictly designed for indoor medium-voltage switchgear applications. The environment must be free from corrosive gas and abnormal condensation. Contact us for outdoor alternatives.
Q2: What secondary current options are available for protection circuits?
Standard secondary options include 1A or 5A. These support both metering and protection accuracy combinations per IEC 61869 standards. Specify your exact ratio requirements during ordering.
Q3: What special environmental conditions require technical confirmation?
Standard ambient temperature ranges from -25°C to +40°C. For high altitude, high humidity, or severe pollution, technical confirmation is required before ordering. Contact our engineering team for details.
Q4: Which rated primary currents can be customized for this model?
Rated primary currents range from 5A to 1000A. Custom ratios outside this standard range are subject to factory confirmation. Provide your specific current requirements to proceed.
Q5: What international standards do these current transformers comply with?
The models comply with IEC 60044-1 and IEC 61869 standards. Specific factory test reports and certification documents are subject to confirmation. Contact our sales team for details.
Q6: What applications are these 12kV epoxy resin transformers used for?
They are designed for indoor medium-voltage switchgear metering and protection applications. Operating at a highest equipment voltage of 12kV, they ensure reliable current transformation. Request a catalog for full manufacturer specifications.