Megger 1001-012 ICLAMP Current clamp for Attached Rod Technique (ART) Ground Resistance Testing

The Megger ICLAMP current probe is designed for measurements of AC currents up to 1000 A with a 1000:1 step-down ratio. The probe offers excellent accuracy (0.3% error at full range) and small phase shift (0.7° at full range) so it can be used for metering of power, energy and power quality applications. Such high performance is achieved because the magnetic cores are made from high-permeability Ni-Fe alloy. The rated terminating resistance (burden) of 1 Ω must be provided by the instrument connecting to ICLAMP. The output terminals of ICLAMP are protected with a voltage limiting circuit ensuring a safe-to-touch voltage under all rated conditions. ICLAMP is rated to CATIV 600 V, according the international standard IEC 61010. Clamp Usage The ICLAMP is intended to clamp around a single phase of the asset to be tested and not phase + neutral because this would yield an incorrect result as a consequence of current flowing in opposite directions. Try to keep clamps separate wherever possible to improve quality of multiphase current measurements. An ammeter measuring up to 1 A can be connected directly to the ICLAMP. A current of 1000 A will result in the ammeter reading 1 A (1000:1 step down ratio). The ICLAMP generates 1 mV output signal across 1 Ω burden resistance for every 1 A of primary current, so if using a multimeter, one with a mV AC range is required. Dedicated earth tester instruments like Megger's DET3TC, DET4TC and DET4TCR will need to ensure the input resistance and measurement circuitry are appropriate for the 1 mV - 1 V input range and a primary current limit of 20 A. If using a TRMS multimeter the voltage reading will be TRMS because of the accuracy and crest factor performance of the ICLAMP