User Guide True RMS AC / DC Power Clamp Meter Model 380940 Introduction Congratulations on your purchase of the Extech 380940 True RMS Watt Clamp DMM. This meter combines multimeter and clamp meter functionality in one convenient meter. Careful use of this meter will provide years of reliable service. Safety 1. NEVER exceed the specified voltage/current maximum 2. USE EXTREME CAUTION when working with high voltages. 3. DO NOT measure voltage if the voltage on the "COM" input jack exceeds 500V above earth ground. 4. NEVER connect the meter leads across a voltage source while the function switch is in the current mode. Doing so can damage the meter. 5. ALWAYS discharge filter capacitors in power supplies and disconnect the power when measuring. 6. ALWAYS turn off the power and disconnect the test leads before opening the back to replace the fuse or batteries. 7. NEVER operate the meter unless the back cover and the battery/fuse door are in place and fastened securely. International Safety Symbols 2 Model 38090A-EU-EN v1.0 2/14 Meter Description 1. Conductor under test 2. Clamp Jaws 3. Jaw trigger – Opens the meter jaws 4. ZERO button – Zeroes the DCA reading 5. Positive input jack (for red test lead) 6. Function select dial 7. HOLD button freezes the displayed reading 8. MAX/MIN button – Press to track and view highest and lowest readings 9. LCD Display with function indicators and bargraph 10. COM input jack (for black test lead) Function Select Switch 3 Model 38090A-EU-EN v1.0 2/14 Display icons Low battery DC Direct current AC Alternating current Minus sign AUTO Automatic range (frequency only) APO Auto Power OFF ZERO Zero / Relative function HOLD HOLD function MAX Highest reading MIN Lowest reading Audible continuity V Voltage unit of measure A Current unit of measure M Prefix MEGA (millions of units) k Prefix KILO (thousands of units) Ohm (unit of measure for resistance and continuity Hz Hertz (unit of measure for frequency) OL Overload (when reading exceeds 4032) Bargraph display The 40 segment bargraph display shown below is a graphical interpretation of the measurement. It is displayed under the display digits on the LCD. The bars in the bargraph indicate a presence of an electronic signal. The more bars showing, the higher the signal. The digits below the graph help the user see how many bars are showing. If 40 segments are showing, the bars will reach the ‘40’ mark, if 20 bars are showing the bars will reach the ‘20’ mark. The bargraph is to be interpreted based on the range the meter is in while the measurement is being made. If the bargraph shows 40 segments lit, then the signal is at the highest end of the meter’s present range. 4 Model 38090A-EU-EN v1.0 2/14 Operation AC + DC Power Watt Measurements 1. Connect the test leads to the voltage source in parallel with the load (refer to diagram). 2. Clamp onto one of the wires connected to the load. 3. Select the AC or DC voltage range using the function select switch and check the voltage reading. 4. Select the AC or DC current range using the function select switch and check the current reading. 5. Select the appropriate Watt range using the function select switch. 6. Read the KW value on the LCD. AC Current Measurements WARNING: To avoid electric shock, disconnect the test leads from the meter before making current measurements. 1. Set the Function switch to the AC Current position. 2. Press the jaw trigger and clamp around a single conductor fully enclosing it. Do not allow a gap between the two halves of the jaw. 3. Read the ACA value on the LCD. 5 Model 38090A-EU-EN v1.0 2/14 DC Current Measurements WARNING: To avoid electric shock, disconnect the test leads from the meter before making current measurements. 1. Set the Function switch to the DC Current position. 2. Press the DCA zero key to null the meter display. 3. Press the jaw trigger and clamp around a single conductor fully enclosing it. Do not allow a gap between the two halves of the jaw. 4. Read the DCA value on the LCD. AC Voltage Measurements WARNING: To avoid electric shock or damage to the meter, do not make any voltage measurements that exceed the maximum specified. 1. Set the Function switch to the AC Voltage position. 2. Insert the test leads to the meter as follows: Red lead to “V, ,Hz” terminal; Black lead to the COM input. 3. Measure voltage with the pointed end of the test leads. Remember that voltage measurements are made in parallel with the device/circuit under test. 4. Read the ACV value on the LCD. DC Voltage Measurements WARNING: To avoid electric shock or damage to the meter, do not make any voltage measurements that exceed the maximum specified. 1. Set the Function switch to the DC Voltage position. 2. Insert the test leads to the meter as follows: Red lead to “V,Ω,Hz,” terminal; Black lead to the COM input. 3. With the pointed end of the test leads measure voltage. Remember that voltage measurements are made in parallel with the device or circuit under test. 4. Read the DCV value on the LCD. Frequency Measurements 1. Set the Function switch to the Hz position. 2. Insert the test leads into the meter’s input terminals. 3. Connect the other ends of the test leads in parallel with the device/circuit under test. 4. Read the Frequency measurement on the LCD in Hz. 6 Model 38090A-EU-EN v1.0 2/14 MIN, MAX Function Pressing the MIN/MAX key allows the meter to display ONLY the highest and the lowest readings encountered. Press the MIN/MAX key once to view the minimum reading, press it again to view the maximum reading. The LCD will toggle between the MIN and MAX values. Press and hold MIN/MAX button for more than 2 seconds to return to normal operating mode. Zero function will be disabled when MIN/MAX is enabled. MIN/MAX is not available in Hz mode. Data Hold To freeze the current reading on the LCD, press the Data Hold key. To release the Data Hold function and return the meter to normal operation, press the Data Hold key again. Relative Mode 1) Press the ZERO key. The displayed reading will zero and the word ZERO will appear on the upper portion of the LCD. 2) All subsequent measurements will now be displayed with respect to the zeroed reading. For example, if a 20A reading is zeroed and a 30A reading is subsequently measured, the LCD will display 10A. 3) Press the zero button once more to return to normal operating mode. 4) Note that Relative mode is not available if MIN/MAX mode is enabled. 5) LCD displays relative numerical value without bargraph. 7 Model 38090A-EU-EN v1.0 2/14 Auto Power OFF To extend battery life, the meter will auto power off after 15 minutes of operation. To resume operation either turn the meter OFF and then ON again or press the HOLD button. Battery Replacement 1. When the low battery symbol appears on the LCD, the batteries must be replaced. 2. Turn the meter off and remove the rear battery compartment screw. 3. Lift off the battery compartment cover and replace the two 1.5V AA cells. 4. Replace the compartment cover and secure the screw. You, as the end user, are legally bound (Battery ordinance) to return all used batteries and accumulators; disposal in the household garbage is prohibited! You can hand over your used batteries / accumulators at collection points in your community or wherever batteries / accumulators are sold! Disposal: Follow the valid legal stipulations in respect of the disposal of the device at the end of its lifecycle Cleaning Use only a dry cloth to clean the plastic case. 8 Model 38090A-EU-EN v1.0 2/14 Specifications General Specifications Display 3‐3/4 digit (4032 count) LCD with 40 segment bargraph Functions Watts, ACA, DCA, ACV, DCV, Frequency Polarity “‐“ indicates negative polarity; positive assumed Current sensor Hall effect sensor type Overload indication OL DCA zero adjust One touch zero key Display rate 3 readings/second (30 readings/second for bargraph) Auto Power Off Meter turns off automatically after 15 minutes Battery Two 1.5V AA batteries Operating temp. ‐100C to 500C (40F to 1220F) Operating Humidity < 85% RH Power consumption Approximately 10mA DC Weight 190g (6.7 oz) including battery Dimensions 183 x 63.6 x 35.6mm (7.2 x 2.5 x 1.4”) (HWD) Jaw opening 23mm (0.9”) maximum conductor size Standards IEC 1010 Category III 300V, Category II 600V 9 Model 38090A-EU-EN v1.0 2/14 Range Specifications Function Range Resolution Accuracy Overload protect AC Power 40kW 10W ±(1.5% + 3dgts) 250V, 400A Note: 50/60Hz, PF 0.6 to 1, Vpeak < 360V 240kW 100W 40kW 10W ±(1.5% + 3dgts) 600V, 400A Note: 50/60Hz, PF 0.6 to 1, Vpeak < 850V ±(2.5% + 3dgts) 250V, 400A Note: 40Hz to 100Hz, PF 0.6 to 1, Vpeak < 360V 240kW 100W ±(2.5% + 3dgts) 600V, 400A Note: 40Hz to 100Hz, PF 0.6 to 1, Vpeak < 850V DC Power DC Current AC Current True RMS, Crest factor < 4 DC Voltage AC Voltage True RMS, Crest factor < 4, Input impedance 10MΩ Frequency 40kW 10W ±(1.5% + 3dgts) 250V, 400A 240kW 100W ±(1.5% + 3dgts) 600V, 400A 400A 100mA ±(1.5% + 3dgts) 600A DC 400A 100mA 400V 0.1V 50/60Hz 40 to 100Hz ±1.5% ±3dgts ±2.5% ±4dgts 600A AC ±(1.0% + 2dgts) 800V DC 50/60Hz 40 to 1kHz 600V 1V ±(1.5% + 2dgts) ±(2.0% + 4d) 800V AC 1Hz ‐ 100kHz 0.001‐ 100Hz ±(0.8% + 2dgts) Sensitivity 10V 600V AC Copyright © 2014 FLIR Systems, Inc. All rights reserved including the right of reproduction in whole or in part in any form www.extech.com 10 Model 38090A-EU-EN v1.0 2/14