Overview
The AG5-0.66 indoor plastic case current transformer is a precision electromagnetic device engineered for accurate current measurement and energy metering in low-voltage AC power systems rated up to 660 V. Operating on the principle of electromagnetic induction, it delivers a galvanically isolated secondary current proportional to the primary circuit current, ensuring safe and reliable monitoring in distribution and control applications.
Designed for indoor use, this fully enclosed transformer features a compact plastic housing that provides excellent insulation, moisture resistance, and mechanical protection. Its robust construction supports long-term stability in ambient temperatures ranging from -5°C to +55°C, making it suitable for integration into switchgear, motor control centers, building management systems, and revenue-grade metering installations.
Key Ratings Snapshot
| Parameter | Rating |
|---|---|
| System voltage class | 0.66 kV |
| Rated frequency | 50 Hz |
| Rated secondary current | 5 A or 1 A |
| Accuracy classes | 0.2, 0.2S, 0.5, 0.5S, 5S |
| Rated burden | 5 VA, 10 VA |
| Burden power factor | cosφ = 0.8 (lagging) |
| Ambient temperature | -5°C to +55°C |
| Applicable standards | GB1208-2006; IEC 60044-1:2003 |
| Construction type | Indoor plastic case, fully enclosed |
Model Designation
- A — Current transformer (CT)
- G — Plastic case type
- 5 — Design series (model variant identifier)
- 0.66 — Voltage class (kV)
Construction
The AG5-0.66 features a fully enclosed indoor plastic case design with integrated insulation, offering reliable protection against moisture, dust, and electrical stress. The core is of ring-type (toroidal) magnetic construction, optimized for accuracy and linearity. Primary conductors pass through the central aperture, while secondary windings are precisely wound around the core. Terminals are clearly marked as P1/P2 for primary and S1/S2 (or 1S1/1S2) for secondary, adhering to standard CT polarity conventions. Mounting is supported via standard DIN rail or panel configurations, enabling straightforward installation in confined distribution enclosures while maintaining safety and performance integrity.
Technical Parameters
Service Conditions
- Installation environment: Indoor installation only
- Altitude: Not exceeding 1000 m above sea level (higher altitude shall be specified for engineering confirmation)
- Ambient temperature: −5°C to +55°C
- Relative humidity: Daily average ≤ 95%, monthly average ≤ 90%
- Environmental conditions: Free from corrosive gases or vapors; free from explosive or flammable media; no severe vibration, mechanical shock, or impact
Technical Parameters
This section provides selection-oriented technical data for the AG5-0.66 series indoor, plastic case current transformer used in 0.66 kV class AC systems (50 Hz). Data shown below is intended for preliminary selection of accuracy class combinations, rated burdens, and primary current ratings.
Data Reference
| Rated Primary Current (A) |
Rated Secondary Current (A) |
Accuracy Classes |
Rated Output (VA) |
|---|---|---|---|
| 5, 10, 15, 20, 30, 40, 50, 75 | 5, 1 | 0.2, 0.2S, 0.5, 0.5S, 5S | 5, 10 |
Installation & Wiring
Outline Dimensions
The AG5-0.66 current transformer features a compact plastic case designed for indoor use. Mounting can be achieved via standard 35-mm DIN rail using integrated clips or through panel mounting using screws at the designated holes shown in the drawing. The primary aperture accommodates busbar passage, while P1 and P2 terminals allow for direct conductor connection. Ensure sufficient clearance around the unit to permit safe installation, removal, and adequate heat dissipation during operation.
Selection & FAQs
Selection Guide
- Select a 5A–75A primary ratio from the circuit load and required measurement range.
- Choose a 1A or 5A secondary that matches the connected meter, controller, and cable length.
- Specify the required accuracy class and calculate whether 5VA or 10VA covers the total burden.
- Confirm the primary conductor arrangement and available clearance around the compact housing.
- Select DIN-rail or panel mounting and verify polarity, terminal access, grounding, and ambient conditions.
Frequently Asked Questions
Q1: Which accuracy class is suitable for revenue metering?
Select 0.2S or 0.5S classes for precise revenue metering in 0.66 kV systems. These classes ensure high accuracy across varying load conditions. Contact our engineering team for specific burden calculations.
Q2: Can this current transformer be installed outdoors?
No, the AG5-0.66 series is strictly for indoor installation only. It must be placed in environments free from corrosive gases, explosive media, and severe vibrations. Verify your panel conditions before ordering.
Q3: What are the available primary current ratings?
Rated primary currents range from 5A to 75A, with secondary options of 5A or 1A. Rated output burdens are available at 5 VA or 10 VA. Specify your exact requirements during the selection process.
Q4: Can this CT be used at high altitudes?
Standard models are rated for altitudes not exceeding 1000 m above sea level. For installations at higher elevations, please specify the exact altitude for engineering confirmation and potential derating adjustments.
Q5: Do you provide custom terminal allocation and integration?
Yes, application engineering support includes terminal allocation and panel integration guidance. Custom configurations are subject to factory confirmation. Contact our sales team with your specific panel layout details.
Q6: What AC systems is this plastic case CT designed for?
The AG5-0.66 indoor plastic case current transformer is designed for 0.66 kV class AC systems operating at 50 Hz. It is ideal for indoor switchgear and power distribution panels.
Q7: How do I request application engineering support?
Our manufacturer provides comprehensive application engineering support for burden calculation and accuracy assessment. Submit your project specifications to our technical department to receive tailored integration recommendations and selection guidance.