Product Overview
The LZZBW-10 / LZZBW-11W outdoor current transformer is a single-phase pillar-type current transformer with fully enclosed epoxy resin cast insulation. It is designed for outdoor current measurement, electric energy metering and relay protection in 11 kV, 13.8 kV and 15 kV medium-voltage power systems with rated frequency of 50 Hz or 60 Hz.
This product should be positioned as an outdoor industrial post-type CT for multi-standard distribution networks. Unlike indoor cast-resin CTs that are mainly selected by cabinet size and secondary-core arrangement, the LZZBW platform focuses on outdoor insulation durability, UV resistance, arc resistance, aging resistance, moisture protection, anti-pollution performance and long-term exposed service. It is suitable for utilities, industrial substations, outdoor metering units and distribution automation projects requiring IEC and ANSI/IEEE reference compatibility.
Product Type
| Item | Specification |
|---|---|
| Product name | Outdoor Pillar Single-Phase Cast-Resin Current Transformer |
| Model series | LZZBW-10 / LZZBW-11W |
| Installation condition | Outdoor |
| Structure | Fully enclosed epoxy resin cast, pillar / post type structure |
| System voltage application | 11 kV, 13.8 kV and 15 kV medium-voltage systems |
| Rated frequency | 50 Hz / 60 Hz |
| Rated secondary current | 5 A or 1 A |
| Core application | Measurement, energy metering, voltage-control signal reference and relay protection |
| Insulation material | Outdoor-special epoxy resin with UV, arc and aging resistance |
| Reference standards | IEC 60044-1, IEC 61869-2 and ANSI/IEEE C57.13 |
Product Display
Applications
- Outdoor 11 kV, 13.8 kV and 15 kV distribution feeders
- Outdoor substations and industrial medium-voltage distribution systems
- Outdoor metering units and high-voltage metering boxes
- Current measurement and electric energy billing circuits
- Relay protection and distribution automation signal input
- Projects requiring IEC 60044-1, IEC 61869-2 or ANSI/IEEE C57.13 reference compatibility
Features
- Outdoor industrial post-type positioning: Designed for exposed outdoor service rather than indoor switchgear-only applications.
- Fully enclosed epoxy resin casting: The core and coil assembly are sealed inside the insulation body to improve moisture resistance and long-term dielectric stability.
- Multi-voltage application range: Suitable for 11 kV, 13.8 kV and 15 kV distribution networks after insulation coordination is confirmed.
- Outdoor-special insulation material: The external insulation uses outdoor epoxy resin with resistance to arc, UV exposure, aging and environmental stress.
- Measurement and protection core design: The transformer can be equipped for metering, current measurement and relay protection functions according to the selected technical table.
- International standard orientation: Performance can be referenced to IEC 60044-1, IEC 61869-2 and ANSI/IEEE C57.13 for utility and industrial projects.
Principle
The LZZBW-10 / LZZBW-11W current transformer converts primary current into a standardized secondary current signal by electromagnetic induction. The primary current generates magnetic flux in the core and the secondary winding delivers a proportional 5 A or 1 A output to meters, relays or monitoring devices.
For outdoor post-type CT selection, ratio and accuracy are only part of the engineering decision. The user should also verify rated voltage level, outdoor insulation distance, creepage requirement, UV and aging resistance, partial discharge performance, secondary terminal sealing, mounting stability and applicable standard.
Model Designation
10: Catalogue voltage class code for outdoor MV CT platform
11W: Outdoor 11 kV-class designation used for 11 kV, 13.8 kV and 15 kV system applications by project confirmation
Technical Data
| Item | Specification |
|---|---|
| Model | LZZBW-10 / LZZBW-11W |
| Installation condition | Outdoor |
| Rated voltage | 11 kV, 13.8 kV or 15 kV |
| Rated frequency | 50 Hz / 60 Hz |
| Rated secondary current | 5 A or 1 A |
| Core and coil assembly | One core and coil assembly for measurement and protection, according to project specification |
| Insulation structure | Fully enclosed epoxy resin casting with outdoor insulation surface |
| Insulation characteristics | Arc resistance, UV resistance, aging resistance and long outdoor service life |
| Application functions | Energy metering, current measurement, voltage-control signal reference and relay protection |
| Applicable standards | IEC 60044-1:2003, IEC 61869-2, ANSI/IEEE C57.13 and project-specific requirements |
Technical Selection
| Selection Item | Recommended Specification |
Engineering Confirmation |
|---|---|---|
| Rated voltage | 11 kV / 13.8 kV / 15 kV | Confirm system voltage and insulation coordination before order. |
| Rated secondary current | 5 A or 1 A | Match meter, relay and secondary cable burden. |
| Accuracy class | Metering and protection classes by project | Confirm energy metering class and relay protection requirement separately. |
| Rated output | According to technical table and burden | Check instrument burden plus secondary wiring burden. |
| Thermal current | According to rated primary current and system fault level | Match short-time withstand requirement of the network. |
| Dynamic current | According to short-circuit condition | Confirm mechanical withstand under fault current. |
| Outdoor insulation | Outdoor epoxy resin surface | Check UV exposure, pollution, humidity and creepage distance. |
Outdoor Insulation
The LZZBW-10 / LZZBW-11W should be selected as an outdoor insulation product, not only as a current-ratio device. The external insulation uses outdoor dedicated epoxy resin, designed for arc resistance, UV resistance, aging resistance and long service life in outdoor power distribution environments.
| Outdoor Factor | Technical Risk | Selection Focus |
|---|---|---|
| UV exposure | Surface aging and insulation degradation | Use outdoor-special epoxy resin with UV resistance. |
| Moisture and rain | Surface wetting and terminal moisture ingress | Confirm terminal sealing and cable outlet protection. |
| Pollution | Surface leakage current and flashover risk | Confirm pollution severity and creepage requirement. |
| Arc and electrical stress | Surface damage under abnormal conditions | Confirm insulation performance and applicable test requirements. |
| Mechanical exposure | Terminal load, vibration and outdoor mounting stress | Confirm mounting base, conductor direction and bracket design. |
Standards Reference
| Standard | Scope | Application Note |
|---|---|---|
| IEC 60044-1:2003 | Instrument transformers – current transformers | Traditional IEC reference for current transformer performance. |
| IEC 61869-2 | Additional requirements for current transformers | Modern IEC reference used in many international CT projects. |
| ANSI/IEEE C57.13 | Instrument transformer requirements | Useful for projects requiring ANSI / IEEE technical reference. |
| Project specification | Customer-specific technical agreement | Final nameplate, test and drawing requirements shall follow the order document. |
Wiring and Terminals
Primary terminals are connected to the outdoor line side according to the approved drawing. Secondary terminals are connected to meters, relays or monitoring devices according to polarity markings. For outdoor installation, secondary terminal sealing, cable outlet direction and grounding arrangement are important for long-term reliability.
| 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. |
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
- The installation environment should be checked for humidity, rain, pollution, altitude, wind load and mounting stability.
- For coastal, industrial pollution, high-humidity or high-altitude projects, creepage distance and insulation coordination must be confirmed separately.
Standards and Compliance
The LZZBW-10 / LZZBW-11W outdoor current transformer can be supplied according to IEC 60044-1:2003, IEC 61869-2, ANSI/IEEE C57.13 and customer-specific technical requirements. For international projects, the final standard scope, accuracy class, insulation test, routine test report and nameplate data shall be confirmed in the technical agreement.
Installation and Dimensions
The product adopts a fully enclosed outdoor post-type structure. Before installation, confirm the mounting base, primary terminal direction, conductor load, phase clearance, secondary terminal box protection, grounding point and cable outlet direction. The approved outline drawing shall be used before pole bracket fabrication, outdoor support installation or replacement work.
Dimensions
| Item | Dimension / Note |
|---|---|
| Structure type | Outdoor fully enclosed post-type cast-resin CT |
| Primary terminal arrangement | According to approved outline drawing |
| Secondary terminal box | Protected terminal area for outdoor wiring |
| Mounting base | Outdoor base or support bracket according to project drawing |
| Creepage distance | Confirmed according to voltage class, pollution level and customer requirement |
| Drawing confirmation | Required before outdoor installation, replacement or support fabrication |
Safety Notes
- Confirm the rated voltage, insulation requirement and outdoor service condition before ordering.
- Check primary terminal direction, conductor stress and mounting-base stability before installation.
- Confirm secondary terminal sealing and cable outlet protection for outdoor service.
- Connect P1/P2 and S1/S2 according to polarity markings and the project wiring diagram.
- The secondary circuit of a current transformer must not be open-circuited when the primary circuit is energized.
- Before disconnecting meters or relays, short-circuit the corresponding secondary circuit through a proper shorting device.
- Installation and maintenance shall be performed by qualified medium-voltage electrical personnel.
Ordering Info
- Product model: LZZBW-10 or LZZBW-11W
- System voltage: 11 kV, 13.8 kV or 15 kV
- Rated primary current and rated secondary current
- Accuracy class and rated output requirement
- Applicable standard: IEC 60044-1, IEC 61869-2, ANSI/IEEE C57.13 or project-specific standard
- Thermal current, dynamic current and outdoor insulation requirement
- Creepage distance, pollution condition and installation altitude
- Outdoor mounting drawing, terminal direction and cable outlet requirement
- Quantity, certificates, routine test reports, labeling and packaging requirements
Selection Guide
- Confirm voltage system: Select this CT for 11 kV, 13.8 kV or 15 kV outdoor distribution applications.
- Confirm outdoor insulation: Check UV exposure, pollution level, moisture condition, creepage distance and insulation coordination.
- Select current ratio: Choose the rated primary current according to feeder load, metering range and relay protection setting.
- Define secondary requirement: Select 5 A or 1 A secondary output and match it with meter or relay input.
- Check accuracy and burden: Confirm metering and protection class, rated output and cable burden.
- Verify standards: Confirm whether IEC 60044-1, IEC 61869-2, ANSI/IEEE C57.13 or customer-specific standard is required.
- Approve final drawing: Confirm terminal layout, mounting base, grounding point and secondary terminal protection before production.