User manual

GMC-I Messtechnik GmbH 43
Measurements: V/Hz, , , Temp (°C/°F), , M
@UISO
, A/Hz
Note
The switch position COIL/M 
@UISO
may only be used for
interturn short-circuit measurement. However, any interfer-
ence voltage accidentally applied is indicated in this switch
position.
If an interference voltage of more than 50 V is present in the
equipment, interturn short-circuit measurement is disabled.
The LCD panel continues to display the interference voltage
and the „Caution: High-Voltage“ symbol. If a voltage of more
than 1000 V is applied, an additional acoustic signal is gen-
erated.
Caution: High-Voltage!
Do not touch the conductive ends of the test probes as long as
the U
COIL ON / OFF key is being pressed.
A voltage of up to 1,200 Volt is present at the two enabled out-
put jacks of the multimeter as well as, in the form of pulsed
voltage, at the two output jacks of the
COIL TEST ADAPTER
(marked with a motor symbol).
Multimeter: A 2.5 mA current (limited in the mesuring instru-
ment) may flow through your body which, although it does
not reach any life-threatening values, is perceptible never-
theless as a slight electric shock.
COIL TEST ADAPTER : Pulsed current of more than 500 A may
be present at the output jacks.
The DUT may charge up: Wait after each mesurement until the
voltage at the DUT has decreased (interference voltage indi-
cation). If not, touching the DUT may pose a danger to life!
Test voltage (U
ISO
= 1000 V)
The test voltage of the interturn short-circuit measurement has
been fixed at 1000 V and cannot be changed. The display shows
the momentary test voltage during measurement.
5.8.2 Performing Interturn Short-circuit Measurement
➭ Contact the winding in question (e.g. U–V) to check for ab-
sence of voltage.
Attention!
!
Do not measure without support, but rather with a self-re-
taining contact, for example alligator clips. Poor contact
may lead to flying sparks, and slipping off the DUT may be
life-threatening!
➭ Activating interturn short-circuit measurement:
Press and hold the U
COIL ON / OFF key for measurement until the
display of the time value has stabilized. In the display, a test
voltage of 1000 V blinks.
➭ Read off the numeric value (indicated in µsec) and note down
the value together with the contacted winding.
➭ Release the U COIL ON / OFF key to stop the measurement.