8.2 Insulation resistance measurement
Do not exceed the maximum permitted voltage with respect to
earth potential! Electric danger!
The highest voltage which may be present at the negative (-) socket and/or at
the positive (+) socket of the BENNING IT 100 with respect to earth potential
is 1000 V. When measuring, avoid arcs occurring for a longer period of time
between the test tips / measuring points, these may lead to unit faults.
During insulation measurements dangerous high voltages can
be present on the test prod tips of the BENNING IT 100. Bear
in mind that these dangerous voltages can also appear on
bare metal parts of the appliance which is being tested. Do not
touch the test tips when the rotary switch is set to 250 V,
500 V or 1000 V.
-
Make the test object voltage free.
-
Select the desired test voltage of 250 V, 500 V or 1000 V with the rotary
switch in the function "M".
-
Connect the black safety measuring cable to the negative socket (-) on the
BENNING IT 100.
-
Connect the red safety measuring cable to the positive socket (+) on the
BENNING IT 100.
-
Connect the safety measuring cables to the measuring point.
-
If an external voltage is present at test prods, its magnitude is shown in
the display . If the external voltage is 30 V AC/ DC or greater, a flashing
warning symbol ( ) in the display and an acoustic signal additionally give
warning that an external dangerous voltage is present. Before proceeding
with the next step, first of all remove the external voltage from the circuit.
-
To start the insulation measurement, press the
pressed.
-
The main display indicates the insulation resistance value. For test tips
without contacts, the full value of the test voltage needs to be indicated
in the top left-hand corner of the display.
-
The
button can be released when an acoustic signal sounds to
indicate that the measured value is stable.
-
Hold the safety measuring cables in contact with the measuring point until
the circuit has discharged completely through the BENNING IT 100. The
falling test voltage is visible in the display . The circuit has discharged
completely when the main display shows "----".
See Fig. 3:
8.3 Low resistance measurement
The low resistance measuring function (switch setting
Ω 200 mA) must not be used in distribution systems with
voltages greater than 600 V.
-
Make the circuit or test object voltage free.
-
Select the desired function " 200 mA" with the rotary switch .
-
Connect the black safety measuring cable to the negative socket (-) of the
BENNING IT 100.
-
Connect the red safety measuring cable to the positive socket (+) of the
BENNING IT 100.
-
To compensate the resistance of the measuring cables (zero adjustment),
connect the two test prods together and hold the
an acoustic signal sounds. The zero adjustment has taken place when the
value 0.00 and the symbol " " appear in the display.
-
Connect the safety measuring cables to the measuring point.
-
If an external voltage is present at the test prods, its magnitude is shown
in the display. If the external voltage is 30 V AC/ DC or greater, a flashing
warning symbol ( ) in the display and an acoustic signal give additional
warning that a dangerous voltage is present. Before proceeding with the
next step, remove the external voltage in the measuring circuit.
-
To start the low voltage measurement, press the
pressed.
11/ 2004
Insulation resistance measurement
BENNING IT 100
button and hold it
button pressed until
button and hold it
15