377/377 FC/378/378 FC
Users Manual
12
L1-L2-L3
Three-phase alternating current (ac) systems are universally used
to distribute electrical power and to supply electricity directly to
high-power equipment. Use the Clamp to make sequential
line-to-ground measurements that result in calculated line-to-line
voltage measurements. These voltage measurements are an
indication that the three-phase system is, or is not, working as
expected.
When you use the Fluke Connect mobile app, the Clamp also
indicates the phase rotation as 1-2-3 or 3-2-1 in the three-phase
system.
To setup:
1.
Turn the control knob to
U
.
2.
Connect the Clamp to ground with the ground lead.
3.
Push
M
for >2 seconds. The Clamp is in the line-to-line
mode and
x-y-z
shows on the display.
To test:
1.
Position the Clamp jaw around the first conductor.
Wait for the measurement on the display to settle. You will
hear a beep and
x
shows on the display.
2.
Move the Clamp jaw to the second conductor within
10 seconds.
Wait for the measurement on the display to settle. You will
hear a beep and
y
shows on the display.
3.
Move the Clamp jaw to the next conductor within 10 seconds.
Wait for the measurement on the display to settle. You will
hear a beep and
z
shows on the display.
When the
x-y-z
measurements are complete, use the Clamp to
calculate the total voltage between each pair of conductors:
1.
Push
M
. The displays shows the total voltage between
L1
and
L2
.
2.
Push
M
again to show the total voltage between
L2
and
L3
.
3.
Push
M
again to show the total voltage between
L3
and
L1
.
While in the line-to-line mode, you can review each line-to-ground
measurement:
1.
Push
M
again to show the
L1
measurement.
2.
Push
M
again to show the
L2
measurement.
3.
Push
M
again to show the
L3
measurement.
To review L1-L2-L3 measurements, continue to push
M
and
scroll through the measurements.
To exit the line-to-line mode, push
M
for >2 seconds.
