User Manual Model 380943 High Resolution 60 Amp AC Clamp-on Meter • 4000 Count Display with 10uA Resolution • 20 reading per second bargraph • Shielded transformer jaws • Selectable filter circuit • MAX/MIN, Relative, & Hold functions • 1.2” (30mm) jaw diameter Introduction Thank you for selecting the Extech 380943 AC Clamp Meter. This device is ideal for checking leakage, ground, and sheath current. This professional meter, with proper care, will provide years of safe reliable service. Specifications General Specifications Display 3-3/4 digit (4000 count) LCD with 40 segment bargraph Functions ACA, ACV, Resistance, and Continuity Polarity Minus sign ( - ) indicates negative polarity Overload indication Left blinking digit Relative Mode ZERO front panel key Display rate 2 readings per second (20 readings per second for bargraph) Battery Two 1.5V AA batteries Operating conditions 4 F to 122 F (-10 C to 50 C); < 85% Relative Humidity 0 0 0 0 0 0 0 0 Storage conditions - 4 F to 140 F (-20 C to 60 C); < 75% Relative Humidity Altitude Operate at less than 2000 meters (Indoor use only) Power consumption Approximately 10mA DC Weight 7 oz. (200g) including battery Dimensions 8.3 x 2.4 x 1.4” (210 x 62 x 35.6mm) (HWD) Jaw opening 1.2” (30mm) Standards IEC 1010 Category III 300V, Category II 600V Range Specifications Range / Resolution Accuracy Accuracy 50/60Hz 40Hz to 1Khz Overload Protection ± (2.0% + 5 digits) 400.0mA ± (1.0% + 3 digits) ± (1.0% + 3 digits) ± (2.0% + 3 digits) 4.000A ± (1.0% + 3 digits) ± (2.0% + 3 digits) 40.00A ± (1.0% + 3 digits) ± (2.0% + 3 digits) 60.0A (0 to 50A)* ± (1.5% + 3 digits) ± (3.0% + 5 digits) 60.0A (50 to 60A)* ± (3.0% + 5 digits) ± (3.5% + 5 digits) ± (1.5% + 2 digits) ± (2.0% + 4 digits) 800V AC Accuracy Audible Continuity Overload Protection ± (1.5% + 2d) Beeps < 38Ω 600V AC AC Current 40.00mA 100A AC AC Voltage 400.0V Resistance and Continuity Range 40.0 to 400.0Ω Specification Notes • Open Circuit Voltage: 0.4V • AC Voltage Input Impedance: 10MΩ • Accuracy specified at 25oC * Displays over 60A are possible but the accuracy of such measurements is not specified 2 Model 380943 Ver. 2.1 11/2002 Meter Description 1. 2. 3. 4. 5. 6. 7. 8. Current sensing jaws Jaws opening trigger Function switch Data HOLD key MAX / MIN key 1 ZERO (Relative) key LCD Display Frequency select slide switch 9. Positive input terminal for V and Ω 10. Negative (COM) input terminal 2 5 6 3 4 7 8 9 10 Safety Information ! Caution ! Refer to the explanation in this Manual Caution ! Risk of electric shock Earth (Ground) Double Insulation This meter has been designed with safety in mind, but the operator must use caution. The rules listed below should be carefully followed for safe operation. 1. NEVER apply voltage or current to the meter that exceeds the specified maximum. 2. USE EXTREME CAUTION when working with high voltages. 3. DO NOT measure voltage if the voltage on the "COM" input jack exceeds 600V above earth ground. 4. ALWAYS turn off the power and disconnect the test leads before opening the meter to replace the fuse or the batteries. 5. NEVER operate the meter unless the back cover and the battery/fuse door are in place and fastened securely. 3 Model 380943 Ver. 2.1 11/2002 Operation Using the Frequency Selector Switch 50/60Hz position (low pass filter) Use the 50/60Hz position when measuring circuits with a frequency bandwidth of 50/60Hz. Since the meter has superior frequency response, measurement results may include higher frequencies and harmonics of the fundamental frequency. Putting this switch in the 50/60 position activates the meter’s low pass filter minimizing the affects of high frequency noise. The filter’s cut-off frequency is 100Hz with 24dB/octave attenuation (approx.). WIDE Position (for high frequencies) Put the slide switch in the WIDE position if the circuit under test is a high frequency generating device (up to 1KHz) such as an inverter, switching regulator, etc. To verify the presence of a high frequency signal, take measurements in both switch positions. If the readings are widely different, then a high frequency signal can be assumed present. AC Current Measurements Basic Current Measurement Procedure WARNING: To avoid electric shock, disconnect the test leads from the meter before making current measurements. 1. Set the Function switch to the desired current range. 2. Set the Frequency slide switch to the appropriate position (refer to the paragraph above to determine which position to use). 3. Press the jaw trigger to open the clamp jaws and clamp around the conductor(s) ensuring they’re fully enclosed by the clamp jaws. 4. Refer to the applications diagrams below for specific measurement configurations. 5. Read the ACA value on the LCD digits and the bargraph. AC Current Applications Load Current Measurments 4 Model 380943 Ver. 2.1 11/2002 Leakage Current on Unbalanced Loads Ground Conductor Leakage Single Phase 2-Wire Leakage Three Phase 3-Wire Leakage Three Phase 4-Wire Leakage AC Voltage Measurements WARNING: To avoid electric shock or damage to the meter, do not make any voltage measurements that exceed the maximum specified limits. 1. Set the Function switch to the Voltage position. 2. Set the Frequency Slide Switch to the appropriate position (refer to the section “Using the Frequency Slide Switch” earlier in this manual). 3. Insert the test leads to the meter as follows: Red lead to the red ‘V’ input terminal; Black lead to the black COM input terminal. 4. Connect the test leads to the circuit or device under test (see diagram example below). 5. Read the ACV value on the meter’s display (LCD digits and bargraph). 5 Model 380943 Ver. 2.1 11/2002