Fluke 187 user manual Input Alert Feature, Measuring Current

Models: 187

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Making Measurements

Measuring Current 3

3.If you are using the A terminal, set the rotary switch to mA/A. If you are using the mA/A terminal, set the rotary switch to A for currents below 5000 A

(5 mA), or mA/A for currents above 5000 A.

4.Open the circuit path to be tested. Touch the red probe to the more positive side of the break; touch the black probe to the more negative side of the break. Reversing the leads will produce a negative reading, but will not damage the meter.

5.Turn on power to the circuit; then read the display. Be

sure to note the unit given at the right side of the display (A, mA, or A).

6.Turn off power to the circuit and discharge all high- voltage capacitors. Remove the meter and restore the circuit to normal operation.

Input Alert™ Feature

If a test lead is plugged into the mA/A or A terminal, but the rotary switch is not correctly set to one of the current measuring positions, the beeper warns you by making a chirping sound and the display shows "LEAd5".

This Input Alert warning is intended to stop you from attempting to measure voltage, continuity, resistance, capacitance, or diode values when the leads are plugged into a current terminal.

Placing the probes across (in parallel with) a powered circuit when a lead is plugged into a current terminal can damage the circuit you are testing and blow the meter’s fuse. This can happen because the resistance through the meter’s current terminals is very low, so the meter acts like a short circuit.

Note

The beeper may sound in the presence of high electical noise, such as that found near Pulse Width Modulation (PWM) motor drives.

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Page 52
Image 52
Fluke 187 user manual Input Alert Feature, Measuring Current