Kusam Meco AC Leakage Clamp On Meter

3¾ DIGIT AC LEAKAGE DIGITAL CLAMPMETER WITH HARMONICS LOW PASS FILTER FUNCTION
Model KM 2007 8 FUNCTIONS 6 RANGES

HIGH FREQUENCY SELECTOR SWITCH
This switch is designed to select “WIDE” or “50/60Hz” range. “WIDE” range covers a wide frequency band of 40Hz to 1kHz. AC current having a fundamental waveform and harmonics can be measured over this range. “50/60Hz” is restricted to a frequency response of 40Hz to 100Hz and therefore permits measurement of AC current of fundamental frequency only by filtering harmonic content. When in doubt as to the presence of harmonics you can indentify it by using this frequency selector switch. To give an example, the following shows the results of AC current measurement on an earthing wire within a switchbox where there is an inverter based airconditioner is connected at summertime. Suppose Model KM-2007 reads 60mA AC with the frequency selector switch set at the “WIDE” position as shown, while it displays 5mA at the “50/60Hz” switch position. The difference between the two readings (60mA - 5mA = 55mA) is considered leakage current caused by harmonics. The test also found that this leakage current is flowing into single phase, 3-wire circuits other than those connected with the inverters in the building inspected.

Wide Frequency Function
If the circuit under test is originated from a high frequency generating device such as inverter, switching regulators, etc., Then the switch should be set at wide position to measure the signal which contains the frequency from 40Hz ~ 1KHz. To make sure the presence of high frequency signal, set the switch at 50/60 Hz and wide position to see the difference. If the reading is very different. It is certain that high frequency signals or harmonics are present.