Overview
The LFZ2-10 is an indoor, semi-enclosed, multi-turn-through type current transformer with epoxy resin cast insulation. It is rated for 10kV class medium-voltage AC systems (also suitable for 11kV and 12kV applications per project specifications) and operates at a rated frequency of 50Hz.
Designed for accuracy and reliability, the LFZ2-10 supports current measurement, electric energy metering, and relay protection functions in indoor switchgear environments. It complies with standard requirements for medium-voltage instrumentation and protection circuits, ensuring stable performance under normal and fault conditions.
Key Ratings Snapshot
| Parameter | Rating |
|---|---|
| Product type | Indoor multi-turn-through epoxy resin cast CT |
| Voltage class | 10kV, 11kV, 12kV |
| Rated frequency | 50Hz |
| Primary winding | Multi-turn-through |
| Insulation material | Epoxy resin cast |
| Installation | Indoor switchgear, vertical or horizontal |
| Typical applications | Measurement, metering, relay protection |
| Secondary output | Proportional current signal per turns ratio |
| Core construction | Laminated magnetic core with wound windings |
| Mounting | Plate with mounting holes and earthing bolt |
| Terminal marking | P1/P2 primary; S1/S2 secondary per winding |
| Environmental suitability | Indoor, non-condensing, pollution degree 2 |
Model Designation
- L: Current transformer
- F: Constructed multi-turn-through type
- Z: Epoxy resin casting insulation
- 2: Design sequence code
- 10: Rated voltage class: 10kV class
Construction
The LFZ2-10 features a semi-enclosed structure with a multi-turn primary winding and epoxy resin cast insulation. Both the primary and secondary windings are wound directly on the magnetic core, and the secondary winding assembly is fully encapsulated in epoxy resin to provide electrical insulation, mechanical strength, and resistance to indoor environmental conditions. The cast-resin body integrates a mounting plate with standardized holes for secure installation in switchgear panels, along with clearly marked terminals (P1/P2 for primary, S1/S2 for secondary). An earthing bolt and warning label are included for safety compliance. This construction ensures reliable separation between the medium-voltage primary circuit and the low-voltage secondary instrumentation circuit.
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 LFZ2-10 is an indoor multi-turn 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 400A.
| Rated primary current (A) |
Accuracy classed combination |
Rated Output (VA) |
Short-time thermal current (kA) |
Rated dynamic current (kA) |
|||
|---|---|---|---|---|---|---|---|
| 0.2 | 0.5 | 1 | 10P10 | ||||
| 5~200 | 0.2/10P10 0.5/10P10 |
10 | 10 | 10 | 15 | 120×I1n | 210×I1n |
| 300~400 | 80×I1n | 160×I1n | |||||
Installation & Wiring
Installation Diagram
The LFZ2-10 current transformer can be installed vertically or horizontally, depending on the switchgear layout. It features a mounting plate with four fixing holes for secure attachment. Primary terminals (P1/P2) and secondary terminal blocks are positioned according to the approved outline drawing, which must be confirmed before cabinet production to ensure proper conductor clearance, terminal access, and insulation distances.
Selection & FAQs
Selection Guide
- Confirm the required highest equipment voltage and dielectric levels because the page provides only a 10kV-class designation.
- Select the project-specific primary ratio and number of primary turns from load, metering range and relay pickup requirements.
- Choose 1A or 5A and specify every metering/protection winding by accuracy class, FS/ALF and terminal marking.
- Calculate meter/relay plus lead burden and obtain numerical VA, thermal-current and dynamic-current ratings.
- Approve P1/P2 terminals, four-hole mounting, vertical/horizontal orientation, earthing, ≤1000m altitude and −5°C to +40°C service.
Frequently Asked Questions
Q1: Can this epoxy resin current transformer be installed outdoors?
No, the LFZ2-10 is strictly designed for indoor medium-voltage switchgear. The installation environment must be free from severe vibration, conductive dust, and corrosive gases. Contact us for outdoor-rated alternatives.
Q2: What is the short-time thermal current rating for 400A models?
For 300A to 400A primary currents, the short-time thermal current is 80×I1n. The rated dynamic current for this range is 160×I1n. Please verify specific fault levels with our engineering team.
Q3: Which accuracy class combinations are available for this 10kV transformer?
The LFZ2-10 offers 0.2/10P10 and 0.5/10P10 accuracy class combinations. Both configurations provide a rated output of 10 VA for measuring cores and 15 VA for protection cores. Specify your exact metering needs during inquiry.
Q4: Are IEC and GB certifications provided for this current transformer?
Yes, the LFZ2-10 epoxy cast-resin current transformer complies with IEC and GB standards. Standard factory test reports are included. Confirm specific third-party certification requirements with our sales team before ordering.
Q5: What is the maximum rated primary current available for this model?
The maximum rated primary current for the LFZ2-10 is 400A, with a minimum of 5A. Custom ratios outside this standard range are subject to factory confirmation. Please share your single-line diagram for exact sizing.
Q6: Are these current transformers suitable for 60Hz power systems?
The LFZ2-10 is specifically rated for 50Hz medium-voltage networks. Operation on 60Hz systems requires factory recalculation and confirmation. Contact our engineering team to verify 60Hz compatibility for your project.