Shielded drive-to-motor cabling is often used to minimize emissions of high frequency signals during power system testing. When this full-cable shielding is used, there can be parasitic currents returned to the AC drive through the cable shields, especially if the shielding is grounded at both ends of the cable (motor and inverter). To avoid letting this return affect your current measurements, it is necessary to break the shielding at the point of the current transducer so that the parasitic currents return outside the transducer aperture. The effects of this parasitic current can be seen as lower current measurements made by the CT and power analyzer, which can lead to inconsistent and unexpected current and efficiency readings for the motor and drive system.
In some power measurement applications, the current in the device under test is higher than what can be applied directly to the power analyzer current input terminals. Current transformers are used to step down high AC and DC currents to a lower level that can be measured directly by the power analyzer. These systems safely step down currents while preserving the highest accuracy.
With 0.02% accuracy and 1MHz bandwidth, the WT3000 delivers where the highest precision measurements are required. It is the industry standard for R&D work on inverters, motor drives, lighting systems and electronic ballasts, UPS systems, aircraft power, transformer testing, and other power conversion devices.
The WTViewerFreePlus software captures measured numeric values, harmonic values, and waveform data. Users can view and save data on a PC using USB, GPIB, RS-232, or Ethernet.
Measure characteristics of devices that generate, transform or consume electricity. Also called power meters or wattmeters, these devices measure parameters such as true power (watts), power factor, harmonics, and efficiency.