Operating Instructions; Switch On; Zero Adjustment; Current Measurement - LEM HEME LH410 Bedienungsanleitung

LH1010
Dimensions ........................ 196 x 71 x 33 mm
Max. jaw capacity ............... 30 mm ø cable
Max. jaw opening ............... 32 mm max.
Weight................................ 295 g

3. OPERATING INSTRUCTIONS

Refer to Fig. 1 for the main operating features of the
meter.

3.1 Switch On

Move the switch from the OFF / HOLD position to either
DC or AC to select the required mode of operation.

3.2 Zero Adjustment

When in DC mode the display zero may change due to
thermal shifts and other environmental conditions.
A manual zero adjustment is provided. Proceed as
follows to perform the adjustment:
•
Ensure that the instrument is away from the current
carrying conductor and that the jaws are closed
during the adjustment cycle.
•
Select the DC position of the power switch.
•
Depress the thumb-wheel zero adjustment control
and rotate it until the display reads zero

3.3 Current Measurement

Select as required the DC or AC measurement option
using the power switch.
If necessary adjust the display to read zero as
described in section 3.2. Clamp the jaws of the probe
round the conductor ensuring a good contact between
the closing faces of the jaws.
Observe and take measurements as required. Positive
output indicates that the current flow is in the direction
shown by the arrow on the probe.
For AC measurements the maximum current is limited
by core eddy current heating which is dependent on the
frequency of the signal f. Core heating occurs when
I
x f > 400,000.
RMS

3.4 Data Hold

To activate the data hold, turn the power switch to the
OFF / HOLD position. The data will be held on the
display for approximately 8 seconds.
4