Fluke 189 user manual Input Alert Feature, Measuring Current

Page 53

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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Image 53 Fluke 189 user manual Input Alert Feature, Measuring Current
Contents Model 187 Lifetime Limited Warranty Table of Contents Making Measurements Model 187Iii Specifications MaintenanceList of Tables Model 187 List of Figures Viii Contacting Fluke Safety InformationBefore You Start WWarning Safety InformationBefore You Start International Electrical Symbols SymbolsTurning the Meter On Getting AcquaintedIntroduction Automatic Power Off Battery ConsiderationsAutomatic Backlight Off Low Battery IndicationRotary Switch Rotary SwitchPushbuttons PushbuttonsBlue Key Function Rotary Switch Selections Position Rotary Switch FunctionView MEM Rotary Switch PositionsButton Pushbuttons Yellow Button Description Function Yellow Button Function Pushbuttons Button DescriptionPrimary Display Selecting the RangeUnderstanding the Display Secondary Display Bar GraphDisplay Features Number Feature Display Features Description 8.8.8 Display Features NumberDisplay Features Description Number FeatureFMS8888 HM8888 8.8 Display Features Number 51000Input Terminals Using the Input TerminalsDisplay Hold and AutoHOLD Using Display HoldUsing MIN MAX Using AutoHOLDModel 187 Min Max Avg Using Fast MN MXUsing Hold with MIN MAX or Fast MN MX Using Relative Mode RELMeasuring Voltage Making MeasurementsAC Voltage Measurement Measuring AC VoltageDBm Display DB Measurements in AC Volts FunctionsBoth AC and DC Voltage Measurements Measuring DC VoltageAC and DC Display AC over DC DC over ACCapacitors before measuring resistance Measuring ResistanceOFF Automatically subtract this value Testing for ContinuityUsing Conductance for High Resistance Tests For in-circuit tests, turn circuit power off Conductance Measurement Measuring Capacitance Capacitance Measurement Testing DiodesDiode Test Electrically live circuits Measuring TemperatureShock, do not connect the thermocouples to Input Ranges Measuring CurrentMeasuring Current Input Alert FeatureFollowing are some tips for measuring current Measuring AC Current11. AC Current Measurement Measuring DC Current Current through one component Total current to circuit13. Functions Allowing Frequency Measurement Measuring Frequency14. Hz Display Measuring Duty CycleMeasures Negative Pulse Measures Positive Pulse16. Duty Cycle Display Measuring Pulse WidthStart and Stop on Negative Slope Start and Stop on Positive Slope18. Pulse Width Display Model 187 Types of Memory Using Memory & Communications FeaturesSaved Readings Memory Logged Readings MemoryStopping Logging Storing Saved ReadingsStarting Logging To avoid electric shock, disconnect the test Viewing Memory DataMEM View DisplayClearing Memory Using Communications 187Model 187 Selecting Setup Options Changing the Default SettingsFactory Default Function Specific Setup SelectionsPrecondition OptionChoices Common Setup SelectionsAdjusting the Temperature Offset Changing the Default Settings Setting the Power Off Timeout Selecting Display Resolution 3 1/2 or 4 1/2 DigitsSetting the Line Main Frequency Setting the 24-Hour ClockSaving Setup Options Returning to Factory DefaultsTesting the Fuses MaintenanceIntroduction General Maintenance Replace F2 if Replace F1 if Displayed Replacing the Batteries Battery and Fuse Replacement Case of Difficulty Replacing the FusesUser-Replaceable Parts MP8 MP9 Safety and Compliances SpecificationsPhysical Specifications Feature Summary Basic Specifications Detailed Accuracy Specifications 45-1 kHz Accuracy Function20 kHz KHz-100 kHzDC a 500.00 Ω Capacitance Diode Test MIN MAX AVG Burden Voltage A, mA, µA Frequency Counter SensitivityInput Characteristics