Overview
The RECT-0.66 is an indoor cast-resin current transformer designed for low-voltage AC power systems with a rated insulation voltage of 0.72/3kV. It employs electromagnetic induction to deliver a galvanically isolated secondary current proportional to the primary current, ensuring safe and accurate measurement in industrial and commercial environments.
Built to high metrological standards, the RECT-0.66 offers accuracy class 0.2, making it suitable for precision energy metering, system monitoring, and protective relaying. It complies with GB20840.1-2010 and GB20840.2-2014, and operates reliably in both 50Hz and 60Hz networks across a primary current range of 100A to 800A.
Key Ratings Snapshot
| Parameter | Rating |
|---|---|
| Insulation Voltage | 0.72/3 kV |
| System Frequency | 50/60 Hz |
| Accuracy Class | 0.2 |
| Primary Current Range | 100 A – 800 A |
| Secondary Current | 5 A (standard) |
| Short-Time Thermal Current | 100 × In for 1 s |
| Rated Burden | ≥ 5 VA (at accuracy class 0.2) |
| Indoor Use Only | Yes |
| Insulation Material | Cast resin |
| Standards Compliance | GB20840.1-2010, GB20840.2-2014 |
Construction
The RECT-0.66 features a robust indoor cast-resin construction, providing excellent dielectric strength and environmental protection against dust and moisture in enclosed switchgear. The core and windings are fully encapsulated in flame-retardant epoxy resin, ensuring mechanical stability and long-term operational reliability. The window-type design allows for easy installation around existing busbars or cables without electrical disconnection.
Technical Parameters
Service Conditions
- Ambient Temperature: -25°C to +40°C
Technical Parameters
The RECT-0.66 Indoor Cast-Resin Current Transformer is designed for indoor use with a rated insulation level of 0.72/3kV and operates at 50Hz or 60Hz. It complies with standards GB20840.1-2010 and GB20840.2-2014, supports secondary currents of 5A or 1A, and covers primary current ranges from 100A up to 800A.
Model Variants
| Model | Rated Primary Current (A) |
Accuracy Class |
Rated Output (VA) |
Aperture Diameter |
|---|---|---|---|---|
| RECT-38A | 100 | 0.2 | 5 | Ø38mm |
| RECT-66A | 150 | 0.2 | 2.5 | Ø66mm |
| RECT-66A | 200-300 | 0.2 | 12.5 | Ø66mm |
| RECT-78A | 300-800/5 | 0.2 | 12.5 | Ø78mm |
Installation & Wiring
Installation
The RECT-0.66 series current transformers feature a window-type design for easy installation around conductors or busbars. The primary conductor passes through the aperture (window) of the transformer, requiring no electrical connection to the primary circuit.
Installation Steps:
- Mount the transformer to a flat surface using the base plate mounting holes
- Pass the primary conductor through the aperture
- Connect the secondary wires to the terminal block (S1, S2)
- Ensure proper polarity marking (P1/P2) for accurate measurement
Terminal Configuration:
- Secondary terminals protected by transparent cover
- 3×M5 dual-purpose terminal screws
- Lead seal port for tamper prevention
Selection & FAQs
Selection Guide
- Select the 100A–800A ratio from the maximum operating current and required measurement range.
- Choose RECT-38A, RECT-66A, or RECT-78A by conductor size, aperture clearance, and panel space.
- Confirm a 1A or 5A secondary and calculate the total burden of the meter, terminals, and cable loop.
- Verify that the class 0.2 rated output for the selected ratio is sufficient for the connected circuit.
- Confirm mounting holes, conductor direction, terminal access, polarity, grounding, and indoor service conditions.
Frequently Asked Questions
Q1: Which aperture diameter fits a 50mm diameter busbar?
The RECT-66A model with a Ø66mm aperture is suitable. It supports primary currents from 150A to 300A. Confirm exact busbar dimensions with our engineering team.
Q2: What accuracy class does this cast-resin CT provide?
All standard model variants feature a 0.2 accuracy class. This ensures precise metering for indoor 0.72/3kV systems operating at 50Hz or 60Hz. Contact us for higher precision requirements.
Q3: Is this current transformer suitable for outdoor environments?
No, it is strictly designed for indoor applications. It operates safely within an ambient temperature range of -25°C to +40°C. Verify installation conditions before ordering.
Q4: How to order primary currents exceeding the 800A maximum?
Yes, custom specifications are available beyond standard ranges. Base models cover 100A to 800A with 5A or 1A secondary currents. Consult the manufacturer for custom parameter details.
Q5: Are these current transformers compliant with international standards?
The RECT-0.66 series complies with GB20840.1-2010 and GB20840.2-2014 standards. It features a rated insulation level of 0.72/3kV. Request specific compliance certificates from our sales team.
Q6: Where are these cast-resin current transformers typically installed?
They are ideal for indoor low-voltage switchgear and power distribution panels. The units support secondary currents of 5A or 1A. Check our catalog for specific application guides.