Key Features:
Ideal for Detecting Bearing Spark Erosion Currents in AC motor drives and high-frequency common mode currents.
Flexible Clip-around Coil: Easy installation around large conductors without interrupting the circuit.
Wide Coil Lengths: Available in 500mm, 700mm, and 1000mm standard lengths. Custom lengths available upon request.
High Peak Current Handling: From 10A peak to 150A peak.
High-Frequency Bandwidth: Up to 14MHz (-3dB) for the CMC06 model.
Low-Frequency Attenuation: Gain of typically -90dB at 50Hz to suppress large fundamental frequency currents.
Accurate Measurements: ±0.5% calibrated accuracy with conductor centrally positioned.
Operating Temperature: 0°C to +40°C for the integrator electronics, -20°C to +90°C for the coil and cable.
Technical Specifications:
| Specification | Details |
| Peak Current (A) | 10A peak to 150A peak |
| Output Voltage | ±7.5V peak |
| High-Frequency Bandwidth | Up to 14MHz (-3dB) for the CMC06 (1000mm coil) |
| Low-Frequency Bandwidth | Varies by model, attenuates large fundamental frequency currents |
| Accuracy (typ.) | Calibrated to ±0.5%, typical variation ±0.3% with conductor position |
| DC Offset | ±3mV maximum at 25°C |
| di/dt Rating | Absolute max: 70kA/µs (peak), 1.5kA/µs (rms) |
| Operating Temperature | 0°C to +40°C (integrator electronics), -20°C to +90°C (coil) |
| Coil Lengths | 500mm, 700mm, 1000mm (custom lengths available) |
| Coil Thickness | 8.5mm (max), 14mm with silicone sleeve for mechanical protection |
| Peak Coil Insulation | 10kV peak |
| Cable Length | 2.5m or 4m (custom lengths available) |
| Power Supply Options | ‘B’: 4 x AA alkaline batteries (25-hour life) |
| ‘R’: 4 x AA NiMH rechargeable batteries (10-hour life) | |
| Output Socket | BNC socket, supplied with 0.5m BNC-BNC cable |
| Integrator Box Dimensions | 183mm x 93mm x 32mm |
| Output Load | ≥100.0kΩ for rated accuracy |
Performance Characteristics:
Low-Frequency Attenuation:
The CMC06 integrator is designed to attenuate low-frequency components, such as fundamental 50Hz currents, with a gain of -90dB at 50Hz. This ensures minimal interference from low-frequency currents, allowing accurate measurement of high-frequency common mode currents.
High-Frequency Response:
The high-frequency response is determined by coil length, cable length, and integrator design. For the CMC06 with a 1000mm coil, the high-frequency bandwidth reaches up to 14MHz, allowing accurate measurement of fast transients.
Noise Characteristics:
The low-noise integrator design enhances the accuracy of high-frequency current measurements, offering a wide dynamic measurement range. Noise levels are kept minimal to ensure precise readings in challenging environments.
Delay Characteristics:
A predictable delay exists between the current and output signal, which is influenced by the coil and cable length. For the CMC03/B/2.5/1000, the delay is approximately 35ns.
Applications:
Measurement of Bearing Spark Erosion Currents: Detect high-frequency current flow through motor bearings in AC drive systems, preventing premature failure.
High-Frequency Common Mode Currents: Identify and monitor common mode currents in large motor drives and variable speed drives (VSDs).
Mitigation Verification: Use the probe to evaluate the effectiveness of grounding or filtering techniques designed to minimize bearing currents.
Ordering Information:
| Model | Power Option | Cable Length (m) | Coil Length (mm) | Peak Insulation (kV) |
| CMC06/B/2.5/500 | Battery | 2.5 | 500 | 10kV |
| CMC03/B/2.5/1000 | Battery | 2.5 | 1000 | 10kV |
| CMC06/R/4/700 | Rechargeable | 4 | 700 | 10kV |