User Guide 1Φ/3Φ 1000 Amp True RMS Power Clamp-On Model 380976
Introduction Congratulations on your purchase of the Extech 380976 Power Clamp-On Meter. This device measures 1Φ/3Φ Power (True, Apparent, and Reactive), Horsepower, Phase Angle, True RMS Current/Voltage, Resistance, Capacitance, Frequency, & Temperature. Power measurements can be achieved on 3- or 4-wire configurations. Please read the entire manual to get the most from the meter’s wide array of capabilities.
Warranty EXTECH INSTRUMENTS CORPORATION warrants this instrument to be free of defects in parts and workmanship for one year from date of shipment (a six month limited warranty applies to sensors and cables). If it should become necessary to return the instrument for service during or beyond the warranty period, contact the Customer Service Department at (781) 890-7440 ext. 210 for authorization or visit our website www.extech.com for contact information.
Meter Description 1. Transformer Jaws 2. Jaw opening trigger 3. Data Hold & MX/MN button 4. Function Selector 5. Range button 6. Temperature input jack 7. LCD Display 8. ‘COM’ input jack 9. ‘V’ input jack 10. Ω µA input jack 4 380976 V3.
Measurements AC + DC Voltage Measurements WARNING The maximum input is 600V. Do no attempt voltage measurements above this limit. Exceeding this limit could cause electrical shock and damage to the meter. 1. Set the rotary switch to the ‘ V’ position. 2. Insert the test leads into the meter’s input jacks. (Black to ‘COM’ and Red to ‘V’) 3. Connect the test leads to the measured circuit. 4. The meter will automatically detect and display AC or DC voltage.
AC Power Measurements 1Φ KW, KVA, KVAR, Power Factor & Phase Angle Measurement 1. Set the rotary switch to the ‘KW/KVA’ position. 2. Insert the test leads to the meter as follows: Black to ‘COM’ and Red to ‘V’. 3. Connect the black lead to the neutral line. 4. Connect the red lead to the power line and clamp onto the same lead to which the red lead is connected. 5. The meter selects automatically. the best range 6. Select the desired display combination using the RANGE key.
3Φ 3-Wire KW, HP, KVA, KVAR, Power Factor & Phase Angle Measurement 1. First, measure WRS(L1L2) (refer to the diagram below). a. Set the rotary switch to the “ b. Press and hold the “HOLD” key while setting the rotary switch to “KW/KVA”, the 3φ3W and WL12 symbols will appear. c. Insert the test leads into the jacks. d. Select a phase (e.g. S or L2) as COM and connect the test probe of the COM (black) terminal to that phase (e.g. S or L2). e.
3. The power clamp will process these two sets of data (WL12 , WL23), and show the result on the LCD. The WL123 symbol will be shown to indicate 3φ3W power. The 3φ3W power (in watts) is stored in the meter memory. 4. To read a single data record, press the “HOLD” key to select desired WL12 , WL23 or WL123 display then press the “RANGE” key to select KW+HP (Horse Power), KW+PF (Power Factor), KW+KVAR, KVA+θ(Phase Angle) or A+V. 5.
NOTE Once a phase is selected as COM, users can not change this selection in the subsequent measurement. For example, if S (or L2) phase is selected, S (or L2) phase is always connected to the COM during measurement of WRS (or WL1L2) and WTS (or WL3L2) in 3φ 3W unbalanced power. NOTE 1. The "+" sign printed on Panel must face the power source for accurate measurement. 2. If the device under test is a switching power supply, the meter KW, PF and θ reading maybe incorrect.
3Φ 4-Wire KW, HP, KVA, KVAR, Power Factor & Phase Angle Measurement 1. First, measure WR(L1) (refer to the diagram below). a. Set the rotary switch to the “ b. Press and hold the “RANGE” key while setting the rotary switch to the “KW/KVA” position, the 3φ4W and WL1 symbols should appear. c. Insert the test leads into the input jacks. V ” position. d. Connect the neutral line to the COM (black) terminal. e. Connect the test probe of the V (red) terminal to the first phase (e.g. R or L1). f.
3. Third, measure WT(L3) (refer to the diagram that follows the steps below) a. Disconnect the test probe from the phase where the jaws were clamped in the previous measurement. b. Connect the test probe of the V (red) terminal to the third phase (e.g. T or L3 phase). c. Clamp the phase where the test probe is connected to (e.g. T or L3). d. The power clamp will automatically select the proper range. e.
4. The power clamp will process these three sets of data (WL1, WL2 WL3) and show the result on the LCD. The WL123 symbol will be shown to indicate the 3φ4W power (refer to diagram). The 3φ4W power value in watts is now stored in the meter’s memory. 5. To read a single data record, use the “HOLD” key to select WL1, WL2, WL3 or WL123 display then press the “RANGE” key to select KW+HP (Horse Power), KW+PF (Power Factor), KW+KVAR, KVA+θ(Phase Angle) or A+V displays. 12 380976 V3.
6. W3φ4W = WR(L1) + WS(L2) WT(L3) KVA 3φ 4W = K W 2 3φ 4W + KVAR PF 3φ 4W = 2 3φ 4W KW 3φ 4W KVA 3φ 4W 7. Set the rotary switch to another position to exit this mode and clear the stored data. NOTE 1. The "+" sign printed on meter must face the power source for accurate measurement. 2. If the device under test is switching power supply, the KW, PF and θ readings may not be correct. NOTE For 3φ4W power measurements, WR or WS and WT must be positive. If one shows negative power, check the connections.
Capacitance Measurements 1. Fully discharge the capacitor under test before proceeding. 2. Insert the test leads into the input jacks. (Black to ‘COM’ and Red to ‘ ’). 3. Set the rotary switch to the ‘ ’ position. 4. Connect the red and black test leads to the capacitor. For Electrolytic (polarized) capacitors, connect the red test lead to the positive side and the black lead to the negative side. 5. Read the capacitance value displayed on the LCD.
Meter Control Keys HOLD - MX/MN Key Data Hold Function Press this key momentarily to put the meter into Data Hold mode (HOLD will appear on the LCD). In this mode, the meter freezes the displayed reading. To exit the Data Hold mode, press the key again (the HOLD icon will switch off). Note that the Data Hold mode is not available for Capacitance measurements. MX/MN (Maximum and Minimum reading mode) The MX/MN mode permits the user to record and recall the highest and lowest readings.
Automatic Sleep Mode and Battery Replacement The Meter is powered by a 9V battery. An AUTO SLEEP feature is included to preserve battery life. Note: The Auto Power OFF feature is disabled when the meter is in the MIN/MAX mode Note: In the sleep mode the meter continues to draw a small amount of battery current. Always turn the function switch to the OFF position when storing the meter.
Specifications General Specifications Display Jaw Opening Max. Input limit Sampling rate Dual Display; 4-digit, 10,000 count (0 to 9999) LCD 1.6” (42mm) Max. voltage between any terminal and ground: 600Vrms 2.5 times per second (Digital Display); Once every 6 seconds (KW, KVA, and KVAR) Auto Sleep After approx. 30 minutes (feature can be defeated) Low battery indication Battery symbol appears on the LCD Power supply 9V Battery Battery life Approx.
Measurement Specifications o o o o Accuracy: ± (% of rdg + number of digits) from 18 C to 28 C (64 F to 82 F) R.H. < 80% AC Current (50Hz to 400Hz) True RMS Range Resolution Accuracy (% reading) Sensitivity 99.99A 10mA ± (2% + 20d) (50, 60Hz) 0.10A 999.9A 100mA ± (4% + 20d) (40~400Hz) 1.0A Overload Protection 1000A μA True RMS (AC+DC) Range Resolution 99.99μA 10nA 999.9μA 100nA Accuracy Sensitivity Overload Protection 0.20µA ±(1% + 20d) 600V 2.
MΩ (Resistance) Range Resolution 9.999MΩ 1KΩ 99.99MΩ 10KΩ Accuracy Overload Protection ±(5% + 10d) 600V Accuracy Overload Protection Capacitance Range Resolution 10.000μF 1nF 100.00μF 10nF 1000.0μF 100nF 7000μF 1μF ±(1.5% + 5d) 600V ±(2.5% + 15d) Diode (Continuity <40mV) Range Resolution Accuracy Overload Protection 2.
1Φ/3Φ Apparent Power (KVA) Range Resolution 60.00KVA (<100A) 10VA 600.0KVA (>100A) 100VA Accuracy Overload Protection ±(2.5% + 20d) 600VAC/1000AAC Phase Angle (50/60Hz) Range Resolution Accuracy Sensitivity -60° ~ 0° ~ +60° 0.1º ±6.0º ACV>100V, ACA>10A Range Resolution Accuracy Sensitivity 40Hz/1KHz 0.1Hz ±(0.5% + 2d) ACV>5V, ACA>6A Frequency Calibration and Repair Services Extech offers repair and calibration services for the products we sell.
