Overview
The LMZB6-10Q(L)/150 is an indoor, fully enclosed, epoxy cast-resin current transformer designed for 10kV, 11kV, and 12kV class medium-voltage switchgear systems. It features a hollow through-window structure that accommodates primary cables or busbars, with magnetic core and secondary windings fully encapsulated in high-quality epoxy resin for enhanced insulation and mechanical durability.
This transformer supports both metering (0.2S/0.5) and protection (5P10 to 5P30) accuracy classes, making it suitable for current measurement, energy metering, feeder monitoring, and relay protection in 50Hz or 60Hz AC power systems. It complies with standard requirements for indoor switchgear applications where reliable performance and long-term stability are essential.
Key Ratings Snapshot
| Parameter | Rating |
|---|---|
| Voltage class | 10kV / 11kV / 12kV |
| Rated insulation level | 12/42/75kV |
| Rated frequency | 50Hz / 60Hz |
| Rated primary current | 1500A – 5000A |
| Rated secondary current | 5A or 1A |
| Metering accuracy | 0.2S, 0.5 |
| Protection accuracy | 5P10, 5P15, 5P20, 5P25, 5P30 |
| Insulation material | Epoxy cast-resin |
| Installation type | Indoor, fixed switchgear |
| Primary conductor | Cable or busbar-through |
| Secondary terminals | External terminal box |
| Structure | Fully enclosed, hollow aperture |
Model Designation
- L: Current transformer
- M: Busbar / cable-through structure
- Z: Epoxy resin casting insulation
- B: Protection-class configuration available
- 6: Design sequence code
- 10: Rated voltage class: 10kV
- Q(L): Reinforced / dimensional variant reference
- 150: Aperture or structural size reference for cable/busbar-through installation
Construction
The LMZB6-10Q(L)/150 features a robust cylindrical epoxy cast-resin body with a square mounting base and a central hollow aperture sized for 150-type cable or busbar passage. The magnetic core and secondary windings are completely encapsulated within the resin matrix, ensuring excellent dielectric strength, moisture resistance, and mechanical integrity. An external secondary terminal box provides clear access for wiring, inspection, and maintenance without requiring disassembly of the main unit. This construction is optimized for fixed indoor switchgear installations where space constraints, thermal stability, and long-term reliability are critical.
Technical Parameters
Service Conditions
- Installation location: indoor medium-voltage switchgear
- Rated voltage: 10kV, 11kV and 12kV class systems by project confirmation
- Rated frequency: 50Hz / 60Hz
- Ambient temperature: -25°C to +40°C
- Installation environment: should be free from severe vibration, corrosive gas, explosive medium, conductive dust, heavy pollution, and abnormal condensation.
- Special service conditions: for high altitude, coastal, humid or heavy-pollution service conditions, technical confirmation is recommended before ordering.
Technical Parameters
The LMZB6-10Q(L)/150 is a cast-resin current transformer designed for indoor 10kV-class systems, with a rated insulation level of 12/42/75kV. It operates within an ambient temperature range of -25°C to +40°C and complies with GB20840.1-2010, GB20840.2-2014, and IEC61869-2:2012 standards. The device supports primary currents from 1500A to 5000A and secondary currents of 1A or 5A, with multiple accuracy class combinations for metering and protection applications.
| Rated Current Ratio (A) |
Accuracy Classes Combination |
Rated Output (VA) |
Accuracy Classes Combination |
Rated Output (VA) |
Total Height (mm) |
|---|---|---|---|---|---|
| 1500/5 | 0.2S/5P15 0.2S/5P20 0.2S/5P25 0.2S/5P30 |
15/40 15/30 15/15 15/20 |
0.5/5P15 0.5/5P20 0.5/5P25 0.5/5P30 |
20/40 20/30 20/15 20/20 |
310 |
| 2000/5 | 0.2S/5P15 0.2S/5P20 0.2S/5P20 0.2S/5P30 |
15/50 15/30 15/20 15/30 |
0.5/5P15 0.5/5P20 0.5/5P25 0.5/5P30 |
20/50 20/30 20/20 20/30 |
|
| 3000/5 | 0.2S/5P15 0.2S/5P20 0.2S/5P20 0.2S/5P30 |
20/50 20/30 20/20 20/30 |
0.5/5P15 0.5/5P20 0.5/5P25 0.5/5P30 |
30/50 30/30 30/20 30/30 |
|
| 4000/5 | 0.2S/5P15 0.2S/5P20 0.2S/5P20 0.2S/5P30 |
30/50 30/30 30/20 30/30 |
0.5/5P15 0.5/5P20 0.5/5P25 0.5/5P30 |
40/50 40/30 40/20 40/30 |
|
| 5000/5 | 0.2S/5P15 0.2S/5P20 0.2S/5P20 0.2S/5P30 |
30/60 30/30 30/20 30/30 |
0.5/5P15 0.5/5P20 0.5/5P25 0.5/5P30 |
40/60 40/30 40/20 40/30 |
| Rated Current Ratio (A) |
Accuracy Classes Combination |
Rated Output (VA) |
Accuracy Classes Combination |
Rated Output (VA) |
Total Height (mm) |
|---|---|---|---|---|---|
| 1500/5 | 0.2S/5P15/5P15 0.2S/5P20/5P20 0.2S/5P25/5P25 0.2S/5P30/5P30 |
15/40/40 15/30/30 15/15/15 15/20/20 |
0.5/5P15/5P15 0.5/5P20/5P20 0.5/5P25/5P25 0.5/5P30/5P30 |
20/40/40 20/30/30 20/15/15 20/20/20 |
360 |
| 2000/5 | 0.2S/5P15/5P15 0.2S/5P20/5P20 0.2S/5P25/5P25 0.2S/5P30/5P30 |
15/50/50 15/30/30 15/20/20 15/30/30 |
0.5/5P15/5P15 0.5/5P20/5P20 0.5/5P25/5P25 0.5/5P30/5P30 |
20/50/50 20/30/30 20/20/20 20/30/30 |
|
| 3000/5 | 0.2S/5P15/5P15 0.2S/5P20/5P20 0.2S/5P25/5P25 0.2S/5P30/5P30 |
20/50/50 20/30/30 20/20/20 20/30/30 |
0.5/5P15/5P15 0.5/5P20/5P20 0.5/5P25/5P25 0.5/5P30/5P30 |
30/50/50 30/30/30 30/20/20 30/30/30 |
|
| 4000/5 | 0.2S/5P15/5P15 0.2S/5P20/5P20 0.2S/5P25/5P25 0.2S/5P30/5P30 |
30/50/50 30/30/30 30/20/20 30/30/30 |
0.5/5P15/5P15 0.5/5P20/5P20 0.5/5P25/5P25 0.5/5P30/5P30 |
40/50/50 40/30/30 40/20/20 40/30/30 |
|
| 5000/5 | 0.2S/5P15/5P15 0.2S/5P20/5P20 0.2S/5P25/5P25 0.2S/5P30/5P30 |
30/60/60 30/30/30 30/20/20 30/30/30 |
0.5/5P15/5P15 0.5/5P20/5P20 0.5/5P25/5P25 0.5/5P30/5P30 |
40/60/30 40/30/30 40/20/20 40/30/30 |
| Rated Current Ratio (A) |
Accuracy Classes Combination |
Rated Output (VA) |
Accuracy Classes Combination |
Rated Output (VA) |
Total Height (mm) |
|---|---|---|---|---|---|
| 1500/1 | 0.2S/5P15 0.2S/5P20 0.2S/5P25 0.2S/5P30 |
15/30 15/20 15/15 15/20 |
0.5/5P15 0.5/5P20 0.5/5P25 0.5/5P30 |
20/30 20/20 20/15 20/20 |
310 |
| 2000/1 | 0.2S/5P15 0.2S/5P20 0.2S/5P20 0.2S/5P30 |
15/40 15/30 15/20 15/30 |
0.5/5P15 0.5/5P20 0.5/5P25 0.5/5P30 |
20/40 20/30 20/20 20/30 |
|
| 3000/1 | 0.2S/5P15 0.2S/5P20 0.2S/5P20 |
20/40 20/25 20/30 |
0.5/5P15 0.5/5P20 0.5/5P25 |
30/40 30/20 30/30 |
|
| 4000/1 | 0.2S/5P15 0.2S/5P20 0.2S/5P20 |
30/40 30/25 30/30 |
0.5/5P15 0.5/5P20 0.5/5P25 |
40/40 40/25 40/30 |
|
| 5000/1 | 0.2S/5P30 | 30/30 | 0.5/5P30 | 40/30 |
| Rated Current Ratio (A) |
Accuracy Classes Combination |
Rated Output (VA) |
Accuracy Classes Combination |
Rated Output (VA) |
Total Height (mm) |
|---|---|---|---|---|---|
| 1500/1 | 0.2S/5P10/5P10 0.2S/5P15/5P15 0.2S/5P20/5P20 |
10/40/40 10/25/25 10/15/15 |
0.5/5P10/5P10 0.5/5P15/5P15 0.5/5P20/5P20 |
15/40/40 15/25/25 15/15/15 |
360 |
| 2000/1 | 0.2S/5P10/5P10 0.2S/5P15/5P15 0.2S/5P20/5P20 |
10/50/50 10/30/30 10/30/30 |
0.5/5P10/5P10 0.5/5P15/5P15 0.5/5P20/5P20 |
15/50/50 15/30/30 15/30/30 |
|
| 3000/1 | 0.2S/5P10/5P10 0.2S/5P15/5P15 0.2S/5P20/5P20 |
10/50/50 10/30/30 10/30/30 |
0.5/5P10/5P10 0.5/5P15/5P15 0.5/5P20/5P20 |
15/50/50 15/30/30 15/30/30 |
|
| 4000/1 | 0.2S/5P10/5P10 0.2S/5P15/5P15 0.2S/5P20/5P20 |
15/50/50 15/30/30 30/30/30 |
0.5/5P10/5P10 0.5/5P15/5P15 0.5/5P20/5P20 |
20/50/50 20/30/30 30/30/30 |
|
| 5000/1 | 0.2S/5P20/5P20 | 10/30/30 | 0.5/5P20/5P20 | 15/30/30 |
Installation & Wiring
Outline Dimensions
The LMZB6-10Q(L)/150 has a 150 mm aperture to accommodate cable or busbar conductors. Key dimensions include total height, mounting hole positions, phase-to-ground clearance, and terminal box orientation—all of which must align with the switchgear layout. Always refer to the approved outline drawing for exact dimensional coordination before cabinet fabrication.
Selection & FAQs
Selection Guide
- Confirm the complete insulated busbar or cable group fits the 150mm opening with mechanical, thermal and phase/earth clearance.
- Select 1500A, 2000A, 3000A, 4000A or 5000A from maximum continuous current, temperature rise and system fault duty.
- Choose 1A or 5A and assign four cores to 0.2S metering, 0.5 measurement and two 5P main/backup protection circuits.
- Select 5P10–5P25 and verify the complete four-value 10VA–60VA burden schedule at cosφ 0.8.
- Approve the 310/360mm body variant, 294mm mounting width, conductor centering, terminal-box direction, support and grounding.
Frequently Asked Questions
Q1: What is the maximum primary current for this cast-resin transformer?
The LMZB6-10Q(L)/150 supports primary currents ranging from 1500A to 5000A. Secondary currents are available in 1A or 5A options. Please specify your exact current ratio during ordering.
Q2: Can this cast-resin current transformer be installed outdoors?
No, it is strictly designed for indoor medium-voltage switchgear. The installation environment must be free from corrosive gas, conductive dust, and abnormal condensation. Contact us if your project requires outdoor applications.
Q3: Which accuracy classes are available for protection and metering?
Multiple accuracy class combinations are supported for both metering and protection applications. Specific rated outputs and class pairings depend on your chosen current ratio. Confirm your exact requirements with our engineering team.
Q4: What international standards does this 12kV class CT comply with?
It fully complies with IEC 61869-2:2012, GB 20840.1-2010, and GB 20840.2-2014 standards. The device features a rated insulation level of 12/42/75kV for reliable indoor performance. Request the official type test report for your project.
Q5: How to order for high altitude or heavy pollution areas?
Standard units are designed for normal indoor environments. For high altitude, coastal, humid, or heavy-pollution conditions, technical confirmation is required before ordering. Contact our sales team to arrange a custom design review.
Q6: Are specific routine factory tests performed before shipment?
Detailed testing protocols and factory certificates are subject to confirmation. Standard compliance is guaranteed per IEC and GB specifications. Please contact our procurement department for exact test documentation.
Q7: Is this manufacturer a direct supplier of 10kV instrument transformers?
Yes, we are a direct manufacturer of cast-resin current transformers for medium-voltage switchgear. The LMZB6-10Q(L)/150 is specifically engineered for 10kV to 12kV class systems. Request our latest product catalog for more details.