Test & Measurement
LEM introduces triple current measurement in single housing
LEM has introduced the HTT series of PCB-mounting current transducers to provide the facility to measure three currents with a single PCB-mounted unit. The new transducers, with maximum measurement currents ranging from 25 to 150 ARMS, allow three-phase currents to be monitored independently by a unit occupying a mounting area of only 16.8 cm2 and with a height of only
29 mm.
LEM 29 mm.
The HTT transducers have three 12 x 10mm apertures for the primary conductors and are securely mounted by four metallic pins, which are soldered to the PCB. Secondary connections for power supply, 0 V and the three voltage outputs are also made to the PCB by pins.
Five different models using the same housing are available to cover nominal current measurements of 3 x 25, 50, 75, 100 or 150 ARMS, working with a bipolar power supply of ± 12 to ± 15 V. The use of open-loop Hall-effect technology allows DC, AC or pulse currents to be measured and provides galvanic isolation between the primary and output circuits, withstanding a test isolation voltage of 2.5 kVRMS/50Hz/1min.
The transducers conform to the EN 50178 standard and are CE marked according to European Directive 2004/108/EEC. They are particularly suitable for industrial applications and home appliances, such as variable speed drives, UPS, SMPS and air-conditioners. The HTT series is covered by a five-year warranty.