Tektronix DMM4020 Digital-Multimeter, DMM, VFD-Multiple segment, 20000 counts CAT II 600 V DMM4020-A1 Data Sheet

2-4 

The Meter operates on four different input line voltages. The selected line-voltage setting 

is visible through the window in the line-fuse holder on the Meter’s rear panel.  

1.  Unplug the power cord. 
2.  Insert a small screwdriver blade into the narrow recess to the left of the fuse 

holder and pry it to the right until the holder pops out. See Figure 2-1. 

3.  Remove the voltage-selector block from the fuse holder. 
4.  Rotate the selector block until the desired voltage rating faces outward. 
5.  Replace the selector block back into the fuse holder. 
6.  Install the fuse holder back into the Meter and reconnect the power cord. 

Changing the line-voltage setting may require a different line-power fuse for proper 

operation. 

The Meter uses one fuse to protect the line-power input and two fuses to protect the 

current-measurement inputs. 

The Meter has a line-power fuse in series with the power supply. Table 2-1 indicates the 

proper fuse for each of the four line-voltage selections. The line-power fuse is accessed 

through the rear panel. 

1.  Unplug the power cord. 
2.  Insert a small screwdriver blade into the narrow recess to the left of the fuse 

holder and pry it to the right until the holder pops out. See Figure 2-1. 

3.  Remove the fuse and replace it with a fuse of an appropriate rating for the 

selected line-power voltage. See Table 2-1. 

4.  Replace the selector block back into the fuse holder. 

XW

 Warning 

100 / 120 

0.125 A, 250 V (slow blow) 

220 / 240 

0.063 A, 250 V (slow blow)