Major tech MT790, Instruction Manual

8

Press 

HOLD

 to enter the Hold mode in any mode,    appears 

and the Meter beeps. 
Press 

HOLD

 again to exit the Hold mode to return to 

measurement mode, the Meter beeps and,     disappears. 
Press the backlight button when needed. The backlight will 
auto off after 20 seconds. Press the button again to turn the 
backlight off manually.
At Active power (main display) + Phase angle (secondary 
display) mode, press 

Σ 

once button to sum up the current 

phase of 3 phase measurement results. Then carry out second 
phase power measurement. 
Press 

Σ 

and hold for over 1 second to sum up the phase 

power measurement result which had been selected. 
If you didn`t select any phase of 3 phase, 

Σ 

is invaild. 

Press once to store single reading, and the Meter beeps. The 
index number shown on the left secondary display will keep 
on increasing. The maximum number of data store 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 zero, then restart the timing. 
At all other ranges, press 

CLEAR

 and hold for over 1 second 

to clear stored readings. 
Press once to enter Memory Record mode,        appears and 
the Meter beeps.
 If the Meter steps through the sum of power press ▼/▲ 
button to switch display of active power (main display) , sum 
of reactive power (secondary display) , sum of power factor 
(main display) and sum of apparent power. 
In the MR mode, press ▼/▲ to select recoded data. 
Measurement data will be sent to the PC 

Button

Operation Performed

6. FUNCTION    

Below table indicated for information about the functional button 
operations. 

HOLD

Σ

SAVE 

SEL

MAXMIN

CLEAR

MR 

▼/▲ 

USB 

H

H

FUL

MR