Three-Phase Through-Type Current Isolating Transformer (ICT)

Tagline High-Accuracy, Wide-Range Current Isolation for Energy Meter Testing

Overview

When testing three-phase energy meters whose voltage and current circuits are inseparable (closed links), current isolation is required to ensure accuracy. For multi-meter and complex three-phase test setups, voltage isolation alone is insufficient. The ICT provides true 1:1 current isolation with electronic error compensation, enabling precise, safe, and flexible calibration under equipotential conditions.

Each ICT contains three independent 1:1 current transformers, supporting:

• Three-phase energy meters with non-separated voltage/current circuits
• Single-phase meters under non-separated conditions
• Multi-station meter test benches with equipotential current supply per position

To maintain high accuracy across different meter types and burdens, the ICT integrates an electronic error compensator and offers ample secondary output capacity. At 200 A, the secondary can deliver over 120 VA while maintaining accuracy. Secondary open-circuit/overload conditions are monitored with indication and automatic short-circuit protection.

Key Features

• Ultra-wide range: 0.1–200 A primary / 0.1–200 A secondary (1:1)
• Single-turn through-type structure for low loss and high efficiency
• High output capacity: up to 140 VA at 200 A
• Electronic error compensation for 0.01% class accuracy over wide range
• Secondary open-circuit and overload indication, alarm, and automatic short-circuit protection
• External status indicators and control buttons for ease of use
• Supports multi-ICT series primary connection with isolated secondary outputs per meter position

Typical Applications

• Three-phase and single-phase energy meter calibration (closed-link meters)
• Multi-position meter test benches using equipotential method
• Utility and metrology labs requiring high-accuracy current isolation

Technical Specifications

• Accuracy class: 0.01% [cosφ = 0.5C … 1 … 0.5L]

• Current range:

  • Primary: 0.1–200 A
  • Secondary: 0.1–200 A (1:1 ratio)

• Frequency: 50/60 Hz ±5%

• Output load:

  • 0.1–1 A: Z = 0.5 Ω
  • 1–200 A: permissible burden ≈ 0.6 V divided by current value

• Burden/voltage limits:

  • Maximum secondary output load voltage: 0.7 V
  • Secondary output capacity: ≥120 VA at 200 A (typ.), max output power up to 140 VA at 200 A

• Insulation:

  • Primary to secondary; windings to enclosure: 2500 V/1 min, leakage < 5 mA

• Environmental:

  • Operating temperature: +22 ℃ ±5 ℃

• Power supply:

  • Auxiliary: 2 × 13.5 V AC, 50/60 Hz, ±5%

Connection Guidelines

• For multi-ICT setups: Connect primaries in series; use each secondary independently to supply the meter under test.
• Use the provided protection features to prevent secondary open-circuit conditions at high current.

Safety & Protection

• Secondary open-circuit/overload detection with visual indication and alarm
• Automatic secondary short-circuit to protect devices and maintain stability
• High insulation strength between primary, secondary, and enclosure

Ordering Information

• Model: Three-Phase Through-Type Current Isolating Transformer (1:1, 0.1–200 A)
• Accessories: Power cables (AC 12–0–12), 7-pin I/O terminal plug, quick-start guide

Notes

• Accuracy specifications apply within stated burden and environmental conditions.