GMC-I Messtechnik GmbH
11
Testing the LED which Indicates Detection of Interference Voltage
when Switched Off – OFF Switch Position
Ð
Apply a voltage of greater than 50 V (+ and COM jacks).
Ð
Turn the rotary switch to the V position.
Ð
Read the voltage value at the analog display.
Ð
Turn the rotary switch to the OFF position.
Test results:
If applied voltage is unchanged and the LED which
indicates the detection of interference voltage lights up red, the
LED is OK. In this case, the LED reliably indicates interference
voltage even when the instrument is switched off. We recom-
mend executing this test at regular intervals.
Limit Values for Insulation and Low-Resistance Measurements
Limit LEDs for Insulation Resistance and Low-Resistance
Measuring Ranges
The
Limit
LED
lights up
green
if the measured insulation resistance
value does not violate the limit value. The
Limit
LED
lights up
red
, if
the measured insulation resistance value violates the limit value. If
the
Limit
LED
does not light up at all, this means that the selected
test voltage value has not been reached. A battery test is advis-
able in this case.
4.2
Analog Display
Insulation Resistance Measuring Ranges
The logarithmic representation of the upper resistance scale
allows for quick recognition of the order of magnitude.
In order to achieve the required accuracy during protective mea-
sures testing, the
10k-1T/100k-100M
key makes it possible to
switch to the expanded lower measuring range of 100 k
100 M
.
The two
orange
LEDs,
➀
and
➁
, indicate which of the two resis-
tance measuring ranges is active at the moment.
Low-Resistance Measuring Range
LED
➃
lights up orange to indicate that low-resistance measure-
ment is active.
LED
➃
blinks when the measuring range is
exceeded.
Voltage Measuring Ranges
The two lower scales are for voltage measurement and the bat-
tery test (see section 3.1).
LED
➃
lights up orange in order to indi-
cate that voltage measurement is active.
Measuring Range Overflow in the Resistance Measuring Ranges
The LED assigned to the respective measuring range, namely
➀
,
➁
or
➃
blinks orange in the event of measuring range overflow.
Scale Illumination
Scale illumination is active for about 15 seconds after switching
the instrument on, after a measurement is started and after
changing measuring ranges.
Limit R
ISO
/ R
INS
50 k
@ U
ISO
/U
INS
= 50
V
100 k
@ U
ISO
/U
INS
= 100
V
500 k
@ U
ISO
/U
INS
= 250
V
1 M
@ U
ISO
/U
INS
= 500
V
1 M
@ U
ISO
/U
INS
= 1000 V
Limit R
LO
2
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