User Manual

GMC-I Messtechnik GmbH 5
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.
Bild 3.10 STOP: Indication
of Overheating
Figure 3.11: Indication of Over-
heating After
Pressing the
START Key
TEST
✓
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
S