Overview
The LZZBW-10 / LZZBW-11W is a single-phase pillar-type current transformer with fully enclosed epoxy resin cast insulation, designed for outdoor use in 11 kV, 13.8 kV and 15 kV medium-voltage power systems operating at 50 Hz or 60 Hz.
It supports applications including current measurement, electric energy metering, relay protection and distribution automation. The transformer complies with international standards IEC 60044-1, IEC 61869-2 and ANSI/IEEE C57.13, making it suitable for utility and industrial projects requiring multi-standard compatibility.
Key Ratings Snapshot
| Parameter | Rating |
|---|---|
| System voltage | 11 kV, 13.8 kV, 15 kV |
| Rated frequency | 50 Hz / 60 Hz |
| Rated secondary current | 5 A or 1 A |
| Insulation material | Outdoor-special epoxy resin |
| Installation condition | Outdoor |
| Structure type | Pillar / post type, fully enclosed cast-resin |
| Core application | Measurement, energy metering, relay protection |
| Reference standards | IEC 60044-1, IEC 61869-2, ANSI/IEEE C57.13 |
| UV resistance | Yes |
| Arc resistance | Yes |
| Aging resistance | Yes |
| Moisture protection | Fully sealed core and coil assembly |
Model Designation
Construction
The LZZBW-10 / LZZBW-11W features a fully enclosed epoxy resin cast structure with a pillar-type mechanical design optimized for outdoor exposure. The primary conductor passes through the center of the transformer, while the secondary winding and magnetic core are completely encapsulated within the insulation body. This construction ensures high resistance to moisture ingress, UV radiation, electrical arcing, thermal aging and environmental pollution. The external surface is engineered for enhanced creepage performance and long-term dielectric stability under harsh outdoor conditions.
Technical Parameters
Service Conditions
- Installation location: outdoor medium-voltage distribution system
- System voltage: 11 kV, 13.8 kV or 15 kV
- Rated frequency: 50 Hz / 60 Hz
- Rated secondary current: 5 A or 1 A
- Outdoor insulation surface: arc-resistant, UV-resistant and aging-resistant epoxy resin
- Installation environment considerations: humidity, rain, pollution, altitude, wind load and mounting stability
- Special project conditions: For coastal, industrial pollution, high-humidity or high-altitude projects, creepage distance and insulation coordination must be confirmed separately.
Technical Parameters
The LZZBW-10L/185 and LZZBW-11W are pillar-type single-phase current transformers designed for outdoor use in medium-voltage systems up to 15 kV. They feature fully enclosed cast-resin insulation with UV, arc, and aging resistance, suitable for operation under standard ambient temperatures and altitudes up to 1000 m (with engineering confirmation for higher elevations). Compliant with IEC 60044-1:2003, IEC 61869-2, and ANSI/IEEE C57.13, these units support rated secondary currents of 1 A or 5 A and are engineered for both metering and protection applications.
| Rated Primary Current (A) |
Accuracy Classes Combination |
Rated Output (VA) |
Short-Time Thermal Current (kA/1s) |
Rated Dynamic Current (kA) |
|---|---|---|---|---|
| 10–40 | 0.2S / 0.5 / 5P10 0.2S / 0.5 / 5P15 0.2S / 0.5 / 5P20 0.2S / 0.5 / 5P30 0.2S / 0.5 / 5P10 / 5P10 0.2S / 0.5 / 5P15 / 5P15 0.2S / 0.5 / 5P20 / 5P20 0.2S / 0.5 / 5P30 / 5P30 |
20 / 20 / 100 20 / 20 / 60 20 / 20 / 40 20 / 20 / 25 20 / 20 / 40 / 40 20 / 20 / 30 / 30 20 / 20 / 20 / 20 20 / 20 / 10 / 10 |
150 × I1n (A) | 375 × I1n (A) |
| 50–100 | 200 × I1n (A) | 500 × I1n (A) | ||
| 150–250 | 32 | 80 | ||
| 300–400 | 50 | 125 | ||
| 500–600 | 63 | 160 |
| Rated Primary Current (A) |
Accuracy Classes Combination |
Rated Output (VA) |
Short-Time Thermal Current (kA/1s) |
Rated Dynamic Current (kA) |
|---|---|---|---|---|
| 750–800 | 0.2S / 0.5 / 5P10 0.2S / 0.5 / 5P15 0.2S / 0.5 / 5P20 0.2S / 0.5 / 5P30 0.2S / 0.5 / 5P10 / 5P10 0.2S / 0.5 / 5P15 / 5P15 0.2S / 0.5 / 5P20 / 5P20 0.2S / 0.5 / 5P30 / 5P30 |
30 / 30 / 120 30 / 30 / 80 30 / 30 / 50 30 / 30 / 30 30 / 30 / 50 / 50 30 / 30 / 30 / 30 30 / 30 / 25 / 25 30 / 30 / 15 / 15 |
80 | 200 |
| 1000–2000 | 100 | 250 |
Wiring and Terminals
| Terminal Area | Function | Engineering Note |
|---|---|---|
| P1 / P2 | Primary current direction | Connect according to line direction and approved outdoor drawing. |
| S1 / S2 | Secondary current output | Connect to meter, relay or monitoring device according to polarity. |
| Grounding point | Safety grounding | Grounding shall follow substation and outdoor equipment requirements. |
| Secondary shorting device | Maintenance safety | Short-circuit the secondary circuit before disconnecting instruments. |
Installation & Wiring
Installation Diagram
The LZZBW-10L/185 and LZZBW-11W pillar-type current transformers are designed for outdoor post mounting. Installation must follow the approved outline drawing to ensure correct primary terminal orientation, phase clearance, conductor load compatibility, and secondary terminal box positioning. The unit features a fully enclosed cast-resin structure suitable for outdoor environments, with provisions for secure grounding and protected cable entry.
Selection & FAQs
Selection Guide
- Confirm the 11kV, 13.8kV, or 15kV system class, frequency, insulation coordination, and applicable IEC or IEEE requirements.
- Select the 10A–2000A primary ratio from the operating current range and protection study, then choose a 1A or 5A secondary.
- Define the number of cores and specify accuracy class, protection class, and VA burden for each circuit.
- Verify the selected configuration’s Ith and Idyn values against the network fault duty.
- Confirm post-mounting dimensions, conductor load, creepage distance, grounding, terminal sealing, and special outdoor conditions.
Frequently Asked Questions
Q1: What applications suit the LZZBW-10/11W outdoor current transformer?
It is designed for outdoor medium-voltage distribution systems up to 15 kV. The cast-resin insulation supports both metering and protection applications in standard ambient conditions. Contact us for specific project requirements.
Q2: Can this 10kV CT be installed in high-altitude environments?
Standard units are rated for altitudes up to 1000 meters. For high-altitude projects, insulation coordination and creepage distances require separate engineering confirmation. Please provide exact site elevation for factory verification.
Q3: Which accuracy classes are available for this pillar-type transformer?
Multiple accuracy class combinations are supported for both metering and protection circuits. The exact class depends on your rated primary current and burden requirements. Consult the technical parameter table or contact our engineering team for specific selections.
Q4: How does the epoxy resin insulation perform in coastal areas?
The outdoor insulation features arc, UV, and aging-resistant epoxy resin. However, coastal or high-pollution environments require increased creepage distances. Submit your specific pollution level and humidity data for customized insulation coordination.
Q5: What international standards does this single-phase current transformer comply with?
The LZZBW-10/11W series complies with IEC 60044-1, IEC 61869-2, and ANSI/IEEE C57.13 standards. These certifications ensure global compatibility for medium-voltage distribution projects. Request the formal compliance declaration from our sales team before ordering.
Q6: Can the rated secondary current be customized for our substation?
Yes, the rated secondary current can be configured to either 5 A or 1 A. Specify your preferred secondary current and rated primary current when requesting a quotation. Final configurations are subject to factory confirmation.