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1. Turn the rotary switch dial to a position away from the OFF position. 

Hearing a beep sound indicates the meter is turned on. The LCD 
displays all symbols firstly and then return to the normal mode. If the 
symbol      is displayed, please changed the battery. 

2. After auto-shut-off, there are some parts of the circuit of the meter 

which still work. If no measurement is needed in a longer time, you'd 
better turn the rotary switch back to the OFF position. 

3. Press the backlight button when needed. Auto shut-down backlight 

after 20 secs. Press the button again, turn the backlight off manually 

7. DISPLAY SYMBOLS (See figure 3)    

Figure 3

 

Summary of Contents for MT790

Page 1: ...INSTRUCTION MANUAL 1000A AC POWER CLAMP METER MT790 ...

Page 2: ...2 ...

Page 3: ...Measurement 13 8 5 Reactive Power Main Display Reactive Power Secondary Display Measurement 18 8 6 Apparent Power Main Display Phase Angle Secondary Display Measurement 18 8 7 Power Factor Main Display Phase Angle Secondary Display Measurement 18 8 8 Active Energy Main Display Time Secondary Display Measurement 20 9 True RMS and Average Value Measurement 21 10 Specifications 22 10 1 Accuracy 22 10...

Page 4: ...n the package case and take out the Meter Check the following items carefully to see if there are any missing or damaged parts WARNING To avoid electric shock or personal injury read the Safety Information and Rules for Safe Operation carefully before using the Meter 1 English Operating Manual 1 piece 2 Red Test Lead 3 piece 3 Red Blue Test Lead 1 piece 4 Red Yellow Test Lead 1 piece 5 Black Test ...

Page 5: ...ations before using the Meter Do not apply more that the rated voltage as marked on the Meter When measurement has been completed disconnect the connection between the test leads and the circuit under test remove the test leads from the input terminals of the Meter and turn the Meter power off Do not carry out the measurement when the Meter s back case and or battery door is opened to avoid electr...

Page 6: ...he surface of the Meter when servicing No abrasive and solvent should be used to clean the surface of the Meter The Meter is suitable for indoor use Turn the Meter off when it is not in use and take out the battery when not using for a long time Constantly check the battery as it may leak when it has not been used for some time replace the battery as soon as leaking appears A leaking battery will ...

Page 7: ...4 SEL button press to select phase and sum of Watts measurement 5 MAXMIN button 6 SAVE button data store button 5 2 The Meter Front Structure see figure 2 7 LCD Display 8 L2 Input Terminal Second phase measurement 9 L3 Input Terminal Third phase measurement 10 COM Input Terminal 11 L1 Input Terminal First phase measurement 12 USB button 13 CLEAR button 14 LIGHT button auto display backlight button...

Page 8: ...tore is 99 when it has achieved 99 the Meter shows Press SEL button to step through first phase second phase third phase and the sum of watts Press SEL and hold for over 2 second to enter 3P3W mode Press to start recording maximum minimum this is only valid in voltage current active power and apparent power ranges only At active energy range press CLEAR and hold for over 1 second to reset time to ...

Page 9: ...ol is displayed please changed the battery 2 After auto shut off there are some parts of the circuit of the meter which still work If no measurement is needed in a longer time you d better turn the rotary switch back to the OFF position 3 Press the backlight button when needed Auto shut down backlight after 20 secs Press the button again turn the backlight off manually 7 DISPLAY SYMBOLS See figure...

Page 10: ...aph Indicator for clear the stored reading Negative symbol High voltage symbol Indicator for AC voltage or current Indicator for recall the stored reading Frequency symbol Indicator for data store Indicator for data stored is full Data hold is active Button Operation Performed h HZ PG KVAr Σ W S CLEAR AC MR Hz MEM FUL USB mm MAX MIN 8 MEASUREMENT OPERATION 8 1 Preparation Dial the Rotary to any ac...

Page 11: ...is is normal operation 8 2 AC Voltage main display Frequency secondary display Measurement see figure 4 The AC Voltage ranges are 100V 400V and 750V The frequency range is 50Hz 60Hz To measure AC voltage frequency connect the Meter as follows 1 Insert the red blue yellow test lead into the L1 L2 L3 input terminal and black test lead to the COM input terminal 2 Dial the Rotary to VAC to select Volt...

Page 12: ...ys it starts recording the minimum AC voltage True RMS value Press MAXMIN again to show the current AC voltage True RMS value 8 The display shows 0L when the input voltage is higher than 750V rms Note When the measurement has been completed disconnect the connection between the test leads and the circuit under test and remove test leads from the input terminals 8 3 AC Current main display AC Volta...

Page 13: ...n the current of the tested conductor is higher than 1000A rms Note When the measurement has been completed disconnect the connection between the conductor under test and the jaw and remove the conductor away from the transformer jaw of the Meter 13 8 4 Active Power main display Phase Angle secondary display Measurement WARNING To avoid damages to the Meter or harms to you do not measure higher th...

Page 14: ...14 Red Figure 6 Measuring Instruction 1 Press SEL to choose first phase see figure 7 The double displays show the active power kW value and the PG value of the second phase 1 Figure 7 Ø1 Ø1 ...

Page 15: ...ding the current power measurement value of the first phase then press SEL to choose The double display shows the value of active power kW and PG of the second phase 2 as in figure 9 If necessary press Σ to get the sum of watts as figure 10 Figure 8 Figure 9 Figure 10 Ø2 Ø2 ...

Page 16: ...e display shows the value of active power KW and PG of the third phase as in figure 11 If necessary press Σ to get the sum of watts as figure12 4 After recording the current power measurement value of the third phase finally press Σ and hold for 1seconds to display the 3 phase sum of active power value and apparent power value as in figure 13 Ø3 Ø3 ...

Page 17: ...se sum of apparent power Press Σ and hold for 1 second again to change back to the normal measuring mode In figure 6 ΣW W1 W2 W3 When measuring 3 phase 3 wires Hold SEL for 5 seconds and the Meter shows press SEL again for 5 seconds to exit 3 phase 3 wires connecting the Meter as figure 15 Figure 14 Figure 15 Red Yellow Black Red Blue 3 3W 3 3W Ø Ø 3 3W Ø ...

Page 18: ...Power secondary display Measurement Please refer to C 8 6 Reactive Power main display Apparent Power secondary display Measurement Please refer to C 8 7 Power Factor main display Phase Angle secondary display Measurement To test for Power factor main display Phase angle secondary display connect the Meter as follows 1 Dial the Rotary to cosθ to select Power factor Phase angle range 2 Press the lev...

Page 19: ...se the second phase see figure 19 Press SEL to choose the second phase see figure 19 The double display shows the second phase value of power factor PF and phase angle PG Then press SEL again to choose the third phase see figure 20 Press SEL to choose the third phase see figure 20 19 Figure 18 Figure 19 Figure 20 ...

Page 20: ... and 3 phases 3 wires see figure 6 and 15 4 Press SEL to choose one of the three phases see figure 21 The double display shows the value of tested object s active energy kWh value and the measuring time of the corresponding phase The measuring reading increases along with the time increasing Press HOLD to read a particular time kWh value Then the reading and time are locked but still continuous ac...

Page 21: ...als 9 TRUE RMS MEASUREMENT AND AVERAGE VALUE MEASUREMENT The True RMS measurement method can measure accurately the effective value of non sine wave input signal Average value measurement method can measure the mean value of one sine wave input signal and then displays it as RMS value When the input waveform has distortion measuring tolerance will be included The total tolerance depends on the tot...

Page 22: ...nce Frequency Range 50Hz 200Hz 1Hz 0 5 5 Range Resolution 10 3 Frequency Accuracy 40A 100A 0 1A 2 5 1000A RMS 50Hz 60Hz 400A 1000A 1A Range Resolution 10 4 AC Current True RMS Accuracy Allowable Maximum Overload Protection Voltage Frequency Range 100V 400V 750V Current 40A 4 00KW 16 00KW 30 00KW Range 100A 10 00KW 40 00KW 75 00KW 400A 40 00KW 160 0KW 300 0KW 1000A 100 0KW 400 0KW 750 0KW Accuracy ...

Page 23: ...1KVAr 100kW 0 1KVAr Current Voltage 10 7 Reactive Power Var V x A x SIN θ Voltages Range 0 3 1 0 022 0 001 The minimum measuring current 10A capacitive or The minimum measuring voltage 45V inductive Measuring current less than 10A OR 0 3 1 For reference only capacitive or Measuring voltage less than 45V inductive Range Resolution 10 8 Power Factor PF W VA Accuracy Measuring Condition 0 90 2 1 The ...

Page 24: ...0 01kVAr 750kVAr 4 5 digits Power Factor 0 3 1 Capacitive or Inductive 0 02 2 digits Phase Angle 0 90 2 Frequency 50Hz 200Hz Active Energy 0 001 9999 kWh 3 2 digits Temperature 50 C 1300 C 58 F 2372 F Special Functions Auto Ranging Single phase 2 wire Balance 3 phase 3 wire 3 phase 4 wire True RMS AC Voltage or Current Data Logging 99 Data Recall Max Min Mode Data Hold USB Display Backlight Full I...

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