Ac Current Measurement - UNI-T UT39E Operating Manual

Model UT39E: OPERATING MANUAL
To measure current, do the following:
1. Turn off power to the circuit. Discharge all high-voltage
capacitors.
2.
Insert the red test lead into the mA or 20A terminal
and the black test lead into the COM terminal. When
measuring current at 200mA below, insert the red test
lead into mA terminal while measuring current 200mA
or above, insert the red test lead into 20A terminal
3. Set the rotary switch to an appropriate measurement
position in A
4. Break the current path to be tested. Connect the red
test lead to the more positive side of the break and
the black test lead to the more negative side of the
break.
5. Turn on power to the circuit.
The measured value shows on the display.
Note
l
If the value of current to be measured is unknown,
use the maximum measurement position (20A) and
20A terminal, and reduce the range step by step until
a satisfactory reading is obtained.
l Replace appropriate rating fuse when the fuse is burnt.
Fuse specification: 0.315A. 250V fast type fuse,
5 x 20mm
l
At 20A Range:
seconds and interval not less than 15 minutes.
l
When current measurement has been completed,
disconnect the connection between the testing leads
and the circuit under test.
D. AC Current Measurement (see figure 4 with dotted line)
Warning
Never attempt an in-circuit current measurement
where the voltage between terminals and ground is
greater than 60V or 30V rms
.
If the fuse burns out during measurement, the Meter
may be damaged or the operator himself may be
hurt. Disconnect power supply before making
measurement. Use proper terminals, function, and
range for the measurement. When the testing leads
are connected to the current terminals, do not parallel
them across any circuit.
range.
For continuous measurement 10
10