LEM transducer measures 4kA in rail monitoring
LEM has announced the ITC series of transducers for galvanically-isolated, high-precision current measurements in rail-traction applications.
There are three models, ITC 1000-S, 2000-S and 4000-S, with corresponding nominal current measurement ratings of 1000, 2000 and 4000A(rms).
LEM designed the ITC series for the rail-traction industry sector, reaching the Class 0.5R measurement accuracy when Class 1R is required by the prEN 50463 standard for on-board energy monitoring.
The ITC series features linearity error of under 0.05% with offset currents of less than +/- 20µA.
The rail-traction industry requires unprecedented accuracy necessary of course to maintain optimum control of traction motors, but mainly in energy metering to log energy usage for fiscal purposes, for example in billing power costs for trains that cross regional borders.
The industry is working to a provisional standard designated prEN 50463.
ITC transducers are designed to be insensitive to the position of the primary conductor within their large measurement aperture, offer high insulation test voltage of up to 14kVrms/50Hz/1 min, and have excellent immunity to transient overloads (100kA for 100ms) and to external interferences (such as magnetic fields typical of the rail environment).
Current consumption varies from less than 80mA to under +/-340 mA across the measurement range, from a +/- 24VDC supply. Bandwidth for the ITC 4000-S is 82kHz (3 dB) and the transducers’ apertures allow the insertion of large conductors: 102 mm diameter (for the ITC 4000-S) or 63 mm diameter (for the ITC 2000-S).
The transducers operate over the range –40 to +85°C, and meet or exceed all relevant standards for safety and for the railway operating environment, such as EN 50124-1 and EN 50155.