Overview
The LQZ5-0.66 solid cast-resin low-voltage current transformer is an indoor busbar-type device engineered for accurate current measurement, energy metering, electrical monitoring, and relay protection in AC systems up to 0.66kV. Its fully enclosed epoxy resin encapsulation ensures excellent insulation performance, high mechanical strength, and reliable moisture resistance, making it ideal for demanding industrial environments.
Available in both LQZJ4-0.66 and LQZ5-0.66 variants, this compact fixed-type transformer mounts directly onto baseplates or busbars within low-voltage distribution cabinets, metering panels, and power monitoring systems. It delivers a standardized secondary output of either 5A or 1A to interface seamlessly with meters, protective relays, and monitoring equipment across industrial, commercial, and mining applications.
Key Ratings Snapshot
| Parameter | Rating |
|---|---|
| Rated voltage | 0.66kV |
| Rated frequency | 50Hz / 60Hz |
| Secondary current | 5A or 1A |
| Phase | Single phase |
| Insulation medium | Epoxy resin (cast-resin) |
| Installation type | Indoor, busbar or baseplate mounted |
| Accuracy classes | 0.2, 0.2S, 0.5, 0.5S |
| Primary current range | As per standard low-voltage ratings |
Model Designation
L – Current transformer category
Q – Coil/winding type structure
Z – Cast-resin insulation structure
5 – Design series / product structure code
0.66 – Rated voltage class: 0.66kV
Construction
The LQZJ4-0.66 and LQZ5-0.66 current transformers feature a robust solid cast-resin construction, with the magnetic core and secondary winding fully encapsulated in high-grade epoxy resin. This monolithic insulation system provides superior dielectric strength, long-term environmental stability, and resistance to humidity, dust, and mechanical stress. The compact fixed housing is designed for secure mounting via baseplate or direct integration onto busbars in indoor low-voltage switchgear assemblies.
Technical Parameters
Service Conditions
- Installation location: indoor
- System voltage: 0.66kV and below
- Rated frequency: 50Hz / 60Hz according to order requirement
- Ambient temperature: -5°C to +55°C according to catalogue data; daily average temperature should not exceed the specified service condition
- Power factor of rated burden: 0.8 lagging unless otherwise specified
- Environmental conditions: The surrounding atmosphere should be free from severe pollution, corrosive gas, explosive medium, conductive dust, and heavy moisture.
- Special requirements: For special altitude, humidity, pollution level, mining application, or cabinet layout requirements, technical confirmation is recommended before ordering.
Technical Data
| Rated Primary Current (A) |
Rated Secondary Current (A) |
Accuracy Class |
Rated Output (VA) |
|---|---|---|---|
| 5, 10, 15, 20, 30, 40, 50, 75, 100 | 5 / 1 | 0.2 / 0.2S / 0.5 / 0.5S | 5 / 10 |
| 150, 200, 250, 300, 400 | |||
| 500, 600 |
Installation & Wiring
Outline Dimensions
The LQZ5-0.66 series features a compact cast-resin design with busbar-type installation. For primary current ranges of 5A–400A, the main outline is approximately 125±1 mm in width and 119±2 mm in height, with an overall installation length of about 174±2 mm. For 400A–600A, dimensions are approximately 130±1 mm wide and 124±2 mm high, with an installation length of roughly 204±2 mm. Final dimensions must be verified against the approved drawing before cabinet layout or production.
Wiring Diagram
Connect the secondary terminals according to polarity markings (S1 and S2) as shown in the wiring diagram and per the project’s electrical schematic. Ensure correct orientation to maintain measurement accuracy and system compatibility. The secondary circuit must never be left open when the primary conductor is energized.
Selection & FAQs
Selection Guide
- Select the 5A–600A primary ratio from the operating current and required measurement range.
- Choose a 1A or 5A secondary that matches the connected instrument and cable length.
- Specify class 0.2, 0.2S, 0.5, or 0.5S and calculate whether 5VA or 10VA covers the total burden.
- Confirm the LQZJ4 or LQZ5 structure, conductor arrangement, and approved mounting dimensions.
- Verify frequency, ambient conditions, polarity, terminal access, grounding, and secondary shorting provision.
Frequently Asked Questions
Q1: Which accuracy class is suitable for revenue metering?
Select 0.2S or 0.5S class for revenue metering. These classes maintain accuracy across varying load currents with 5VA or 10VA rated outputs. Confirm specific burden requirements with our engineering team.
Q2: Can this solid cast-resin CT be installed outdoors?
No, this 0.66kV current transformer is strictly rated for indoor installation. The surrounding atmosphere must be free from severe pollution, corrosive gas, and conductive dust. Contact us for outdoor-rated alternatives.
Q3: What are the available primary current ratings?
The LQZ5-0.66 offers multiple standard current ratings. Primary ratings range from 5A to 600A with 5A or 1A secondary currents. Technical confirmation is required for parameters beyond this specified range.
Q4: How does the rated frequency affect system compatibility?
Frequency selection is critical for accurate measurement. The LQZ5-0.66 operates at either 50Hz or 60Hz depending on your order requirement. Specify your exact frequency during procurement.
Q5: Are custom configurations available for high-altitude mining applications?
Yes, special requirements for altitude, humidity, and mining applications are supported. The standard ambient temperature range is -5°C to +55°C. Technical confirmation is highly recommended before ordering to ensure compliance.
Q6: Why specify the power factor during the ordering process?
Proper power factor specification ensures accurate relay coordination. The default power factor of the rated burden is 0.8 lagging. Notify our sales team if a different power factor is needed.
Q7: Where is this 0.66kV solid cast-resin transformer typically applied?
This current transformer is designed for indoor low-voltage switchgear and power distribution panels. It is rated for system voltages of 0.66kV and below in clean environments. Verify your specific application with our engineers.