TIF900
EN - 10
4.5. Lo
:
CONTINUITY TEST ON EARTH, PROTECTIVE AND EQUALIZING
POTENTIAL CONDUCTORS
The measurement is performed with a test current higher than 200 mA (R<5
Ω
) and open
circuit voltage ranging from 4 to 24V DC according to EN 61557-2 and VDE 0413 part 4.
CAUTION
Before taking resistance measurements make sure that the circuit under test is
not powered and that eventual condensers are discharged. The measured
value is out of accuracy if an input voltage is present.
Fig. 6: Connection of the instrument’s terminals during Lo
test
1.
Turn on the instrument
2.
Press the arrow keys to select Lo
3. Insert the black and red cables in the corresponding input terminals of the instrument
Resistance value
4. If the measuring cables being used have
not been calibrated, first calibrate them
as described in paragraph 4.5.1
5. Position the test probes on the desired
points of the circuit under test (see Fig. 6)
6.
GO
Press
GO
to perform the
measurement
7.
+
GO
Press
LOCK
and
GO
together to perform the measurement in
continuous mode, the symbol
LOCK
is displayed. Press
GO
another time to stop the continuous mode measurement
8. In lock mode the instrument emits an acoustic signal and the auto power off is disabled
4.5.1. "ZERO"
mode
1. Any addition or replacement of cables, extensions and croco clips nullify the previous
calibration and make necessary a new calibration before performing further
measurements. Therefore the instrument must be calibrated in the same conditions at
which it will operate during measurements