Product Overview
The LZX-10 / LZX-10Q / LZX4-10 / LZX5-10 current transformer is an indoor epoxy cast-resin current transformer series for medium-voltage switchgear. It is used for current measurement, electric energy metering, feeder monitoring, and relay protection in AC power systems with rated frequency of 50Hz. For international project documentation, this series should be positioned for 11kV and 12kV class indoor switchgear, with the final selection confirmed according to insulation level, system voltage, accuracy class, and project drawings.
The LZX series is different from larger support-type CTs and wall-through busbar CTs. It is more suitable for compact indoor switchgear panels where a molded cast-resin CT is required for measurement and protection, but where installation space, cost control, and practical wiring access are important. The catalogue data shows a rated insulation level of 12/42/75kV, making the product suitable for 12kV equipment-class documentation commonly used in IEC-oriented markets.
The series includes related model variants such as LZX-10, LZX-10Q, LZX4-10, and LZX5-10. For website structure, it is recommended to combine them into one product page rather than creating multiple similar pages. The main product name can be written as LZX-10 Series Indoor Epoxy Cast-Resin Current Transformer, while the other models are listed as structural or design variants for project selection.
Recommended Model Name
| Website Field | Recommended Wording |
|---|---|
| Main product model | LZX-10 Series |
| Included variants | LZX-10, LZX-10Q, LZX4-10, LZX5-10 |
| Recommended product name | LZX-10 Series Indoor Epoxy Cast-Resin Current Transformer |
| Voltage positioning | 11kV and 12kV class indoor switchgear |
| SEO positioning | Compact 12kV indoor cast-resin CT for metering and protection |
Product Type
| Item | Specification |
|---|---|
| Product name | Indoor Epoxy Cast-Resin Current Transformer |
| Model series | LZX-10 / LZX-10Q / LZX4-10 / LZX5-10 |
| Structure | Indoor epoxy cast-resin structure with compact body, primary terminals, and secondary terminal block |
| Voltage class | 11kV and 12kV class indoor medium-voltage systems |
| Rated insulation level | 12/42/75kV |
| Rated frequency | 50Hz; 60Hz available by project confirmation |
| Rated secondary current | 5A or 1A |
| Rated primary current | 5A to 1000A reference range according to catalogue data |
| Typical use | Current measurement, energy metering, relay protection, feeder monitoring |
Product Display
The LZX-10 series has a compact cast-resin body with primary terminals on the top side and a secondary terminal area at the lower side. The product is suitable for fixed indoor switchgear and compact metering/protection cabinets. The structure is intended for practical installation where the primary connection, secondary wiring, and cabinet clearance must be coordinated in a limited space.
Applications
- 11kV and 12kV class indoor medium-voltage switchgear
- Compact feeder cabinets, metering cabinets, incoming panels, and outgoing panels
- Current measurement and electric energy metering circuits
- Relay protection circuits using 5P or 10P protection classes
- Industrial substations, utility distribution rooms, and OEM switchgear assemblies
- Projects requiring compact 12kV class cast-resin CTs with practical wiring access
Features
- Combined LZX model family: LZX-10, LZX-10Q, LZX4-10, and LZX5-10 can be presented as one product family for clearer website structure and better SEO.
- 11kV / 12kV class documentation: The product can be specified for international 11kV and 12kV switchgear projects when the 12/42/75kV insulation level is confirmed.
- Compact epoxy cast-resin body: The resin body supports insulation strength, mechanical stability, and moisture resistance for indoor use.
- Measurement and protection options: The product supports metering accuracy classes such as 0.2S, 0.2 and 0.5, with protection classes such as 5P and 10P.
- 5A or 1A secondary output: 5A is suitable for conventional metering and relay circuits, while 1A can reduce burden for longer secondary wiring or modern digital devices.
- Practical switchgear integration: The compact terminal layout helps simplify installation in standard indoor distribution panels.
Principle
The LZX-10 series current transformer operates according to electromagnetic induction. Primary current flows through the primary conductor path and produces magnetic flux in the magnetic core. The secondary winding then outputs a proportional low-current signal, normally 5A or 1A, for meters, protection relays, monitoring devices, or automation equipment.
For metering duty, the selected measuring core must maintain ratio accuracy and phase accuracy within the rated burden. For relay protection duty, the protection core must provide a dependable current signal under fault-current conditions. Current ratio, secondary current, accuracy class, rated output, thermal current, and dynamic current should be selected together with the switchgear and protection system design.
Model Designation
| Code | Meaning |
|---|---|
| L | Current transformer |
| Z | Cast-resin insulation / epoxy casting structure reference |
| X | Structural series code for this compact indoor CT family |
| 10 | Catalogue voltage-class reference; documented internationally for 11kV / 12kV class projects by insulation confirmation |
| Q | Reinforced or variant structure reference, depending on drawing and factory designation |
| 4 / 5 | Design variant or structural sequence reference for LZX4-10 and LZX5-10 |
Technical Data
| Item | Specification |
|---|---|
| Rated voltage class | 11kV and 12kV class indoor systems; 10kV compatibility by project confirmation |
| Rated insulation level | 12/42/75kV |
| Rated frequency | 50Hz; 60Hz by agreement |
| Rated secondary current | 5A or 1A |
| Rated primary current | 5A–100A, 150A–200A, 300A, 400A–500A, 600A–1000A reference groups |
| Accuracy classes | 0.2S, 0.2, 0.5, 5P, 10P depending on order |
| Rated output | 10VA to 15VA reference values depending on class and core configuration |
| Short-time thermal current | 90 × I1n, 80 × I1n, 75 × I1n or 50 × I1n depending on current range |
| Rated dynamic current | 225 × I1n, 160 × I1n or 90 × I1n depending on current range |
| Ambient temperature | -5°C to +55°C |
| Applicable standards | IEC 61869-2, GB20840.2-2014; legacy IEC 60044-1 / GB1208 references by project agreement |
Selection Table
The following table is reorganized from the catalogue data for website use. Long headers are split into multiple lines to improve responsive display.
|
Rated Primary |
Accuracy Class |
Rated Output |
Short-Time |
Rated Dynamic |
|---|---|---|---|---|
| 5–100 | 0.5 / 10P15 0.2 / 10P15 |
0.2S / 0.2 / 0.5: 10VA 5P / 10P: 15VA |
90 × I1n | 225 × I1n |
| 150, 200 | 90 × I1n | 160 × I1n | ||
| 300 | 80 × I1n | 160 × I1n | ||
| 400, 500 | 75 × I1n | 160 × I1n | ||
| 600, 800, 1000 | 50 × I1n | 90 × I1n |
Note: The table is intended for preliminary selection. Final current ratio, accuracy class, rated burden, thermal current, dynamic current, terminal arrangement, insulation level, and routine test requirements shall be confirmed according to the nameplate, approved drawing, and factory test report.
Variant Selection
| Variant | Recommended Use | Technical Note |
|---|---|---|
| LZX-10 | Main standard model for compact indoor CT applications | Recommended as the primary product name for website and SEO structure. |
| LZX-10Q | Reinforced or drawing-specific variant | Use when the customer drawing or tender clearly specifies the Q version. |
| LZX4-10 | Related structural variant | Can be listed on the same page to avoid duplicated product content. |
| LZX5-10 | Related structural variant | Use as a cross-reference where the installation drawing or switchgear layout matches this version. |
Dimensions
| Item | Catalogue Reference | Engineering Note |
|---|---|---|
| Structure | Compact cast-resin body with primary terminals and base mounting plate | Final outline depends on the selected LZX variant. |
| Primary terminals | Top-side primary terminal arrangement | Confirm busbar or cable lug connection and phase clearance. |
| Secondary terminals | Lower secondary terminal area | Check secondary wiring access before cabinet production. |
| Mounting base | Bottom mounting plate | Mounting holes and base dimensions must follow approved drawing. |
| Overall dimensions | According to LZX-10 / LZX-10Q / LZX4-10 / LZX5-10 drawing | Do not interchange variants without checking outline dimensions. |
Terminals
The primary terminals are normally marked P1 and P2. Secondary terminals are marked according to the winding configuration, such as 1S1 / 1S2 for measurement or metering and 2S1 / 2S2 for protection where a second secondary winding is supplied. Final marking shall follow the approved wiring diagram and nameplate.
| Terminal | Function | Application Note |
|---|---|---|
| P1 / P2 | Primary terminals | Used for primary current direction and polarity reference. |
| 1S1 / 1S2 | Measurement or metering secondary winding | Used for meters, energy meters, or monitoring devices. |
| 2S1 / 2S2 | Protection secondary winding | Used for relay protection circuit if a protection core is supplied. |
| Grounding point | Protective grounding | Secondary circuit grounding shall follow project electrical safety practice. |
Service Conditions
- Installation location: indoor medium-voltage switchgear
- Rated voltage: 11kV and 12kV class systems by project confirmation
- Rated frequency: 50Hz; 60Hz by agreement
- Ambient temperature: -5°C to +55°C
- Indoor environment should be free from conductive dust, corrosive gas, explosive medium, heavy pollution, and abnormal condensation.
- For high humidity, coastal, high altitude, heavy pollution, or special cabinet layouts, insulation distance and creepage coordination should be confirmed before ordering.
Standards and Compliance
For new international projects, the LZX-10 series should be specified according to IEC 61869-2 current transformer requirements and GB20840.2-2014 where GB documentation is required. Older references such as IEC 60044-1 and GB1208 can be retained as legacy catalogue references when required by the customer or tender document.
Installation and Dimensions
The LZX-10 series is intended for compact indoor switchgear installation. Before cabinet production, the primary terminal spacing, base mounting holes, secondary wiring direction, phase-to-ground clearance, and maintenance access should be confirmed with the approved drawing. Because LZX-10, LZX-10Q, LZX4-10, and LZX5-10 may differ in outline or mounting structure, the final drawing must match the nameplate model.
Safety Notes
- Confirm voltage class, insulation level, current ratio, secondary current, accuracy class, rated burden, and protection class before production.
- Check primary terminal spacing, busbar clearance, mounting holes, secondary terminal access, and grounding position before switchgear assembly.
- Connect primary and secondary terminals according to polarity marks and approved wiring diagram.
- The CT secondary circuit must not be open-circuited while primary current is flowing.
- Before disconnecting meters or relays, short-circuit the secondary circuit with an approved shorting device.
- One point of the secondary circuit should be grounded according to project electrical safety practice.
- Installation and commissioning shall be performed by qualified medium-voltage electrical personnel.
Ordering Info
- Product model: LZX-10 / LZX-10Q / LZX4-10 / LZX5-10
- Voltage class: 11kV or 12kV class
- Rated primary current and rated secondary current: 5A or 1A
- Metering and protection accuracy class combination
- Rated output / burden for each secondary winding
- Protection class requirement: 5P, 10P or project-specific requirement
- Rated short-time thermal current and dynamic current
- Mounting drawing, terminal direction, wiring diagram and switchgear layout
- IEC standard requirement, routine test report, certificate, label language and packaging requirement
Selection Guide
- Use one main product page: Use LZX-10 Series as the main website product and list LZX-10Q, LZX4-10, and LZX5-10 as variants.
- Confirm voltage class: Use 11kV and 12kV class wording for international projects, then verify 12/42/75kV insulation level.
- Select current ratio: Choose from the catalogue current groups according to feeder load and protection setting.
- Specify metering core: Use 0.2S, 0.2 or 0.5 according to metering accuracy requirements.
- Specify protection core: Use 5P or 10P according to relay requirements and fault-current coordination.
- Verify burden: Confirm that meter burden, relay burden and secondary cable resistance do not exceed the selected rated output.
- Approve drawings: Confirm dimensions, mounting holes, primary terminal spacing and secondary terminal layout before production.
FAQs