GMC-I Messtechnik GmbH
5
Tripping During Touch Voltage Measurement
If the display shown in figure 3.7 appears after pressing the
START
key, the RCD has been tripped during touch voltage measure-
ment. This can be caused by an incorrectly adjusted nominal cur-
rent value
I
N
, by a defective RCD or by previously existing leak-
age current via the RCD. This status is displayed until one of the
function selection keys is pressed, or the device is once again
connected to mains power.
Figure 3.7:
Example of Display for Tripping During Touch
Voltage Measurement
Low Battery Voltage
If battery voltage is too low (only the red field is lit up in the battery
symbol), measurement cannot be triggered with the
START
key. If
the key is nevertheless pressed, the depleted battery symbol is
displayed for about 1 second. The instrument is then returned to
its previous status. Replace the batteries with new ones or
recharge them as described in section 5.1.
Overheating
If several measurements with high
I
N
values are performed one
after the other, the red field indicates internal warming of the
instrument. As temperature increases, the red field is gradually
filled in and becomes wider. An inversely displayed
STOP
symbol
appears when the maximum permissible temperature is
exceeded. If the
START
key is pressed, the overheating symbol
appears for about 1 second and further measurements are dis-
abled. The instrument is then returned to its previous status which
prevailed before the
START
key was pressed. Allow the test instru-
ment to cool down, which is indicated by the shrinking tempera-
ture display.
Performing the Measurement
Securely contact the device under test with the test probes before
triggering the measurement by pressing the
START
key. After-
wards, check to see whether or not the displayed line voltage
value is stable. Do not remove the test probes from the device
under test during measurement. Measurement results might oth-
erwise be distorted.
Influences on Measurement Results
•
Current flowing via PE has an unfavorable influence on mea-
surement results, or makes measurement entirely impossible,
due to, for example, consuming devices or capacitance
between L and PE. Consuming devices of this sort should
therefore be removed prior to measurement.
•
Measurement results can be influenced by several factors:
– Leakage current in the measured electrical circuit
– Interference voltage occurring in an earthing system
– When the earthing system is influenced by the potential
of another earthing system
– Fluctuating line voltage
If the symbol shown at the right appears together with
the measurement results, the measurement results for
the respective function lie within the specified limit val-
ues.
3.3
Adjustable Parameters
•
The
limit value for touch voltage
Ucmax
can be set to either 50 V
or 25 V. Adjust with the
xI
N
key when the touch voltage mea-
surement function (Uc) has been activated with the
FUNC
key.
•
The
nominal value for residual current
can be set to one of the
following values with the
I
N
key: 10 mA, 30 mA, 100 mA,
300 mA or 500 mA.
•
The
residual current multiplier
can be set to a value of ½, 1, 2 or
5 for 10, 30 and 100 mA, or to ½ or 1 for 300 and 500 mA
with the
xI
N
key, after the
TIME
function has been activated
with the
FUNC
key.
•
RCD type:
Residual current waveform and polarity are selected
with the
TYPE
key.
Refer to the technical data in section 4 for further details.
Figure 3.5:
Touch Voltage
> 50 V
Figure 3.6:
Touch Voltage
> 25 V
Figure 3.8:
Battery Voltage
Too Low
Figure 3.9:
Battery Status
After Pressing the
START Key
Bild 3.10
STOP:
Indication
of Overheating
Figure 3.11: Indication of Over-
heating After
Pressing the
START Key
Display
Symbol
RCD Type
(residual current waveform)
Initial Polarity of the Re-
sidual Current
AC (sinusoidal)
Positive half-wave
Negative half-wave
A (pulsed)
Positive half-wave
Negative half-wave
Display
Symbol
RCD Type
RCD Type
AC or A
Standard
Selective
TEST
✓
S
