8.2.2
Testing of devices of protection class II (shock-proof) and of devices of
protection class III (safety extra-low voltage)
-
Testing of devices without protective conductor and with accessible conductive parts
-
Connect the test object to the test socket 1 of the BENNING ST 710.
-
Establish a connection between the 4 mm test socket 6 and a metal part of the test object
by means of the test cable with alligator clip.
-
Switch the test object on.
-
Press the key 3 to start the automatic testing procedure.
-
If "Lo LOAD" is shown on the display, please check whether the test object is switched on.
-
Press the key 3 to continue the testing procedure in case of the load being too low (R
100 kΩ).
-
If the insulating resistance R
next to the R
ISO
-
Similarly, a
admissible limiting value.
-
The test is considered to be passed, if "PASS" is shown on the display.
Note on measuring the insulating resistance for test objects of protection class III:
-
Due to the preset limiting value of 2 MΩ for test objects of protection class II, for the testing
of test objects of protection class III it has to be observed that measured values between
the limiting values of 2 MΩ (protection class II) and up to 0.25 MΩ (protection class III) are
indicated with a
See figure 4:
T esting of devices of protection class II (shock-proof devices without protective
conductor and with accessible conductive parts) and testing of devices of pro-
tection class III (safety extra-low voltage)
8.2.3
Cord test
The cord test can be used both for the testing of IEC power cords (device connecting cables with
IEC coupler) and for the testing of cable reels, multiple distributors and extension cables.
8.2.3.1 Testing of IEC power cords (IEC adapter cables)
-
Connect the IEC power cord to be tested to the BENNING ST 710 by means of the IEC
connector 7 and the test socket 1 .
-
Press the key 4 to start the automatic testing procedure.
-
The test starts with measuring the protective conductor resistance R
-
Depending on whether the value is higher or lower than the limiting value, a
indicated next to the R
The protective conductor resistance depends on the length and cross-section
of the line to be tested. It is possible that the measuring result is acceptable
although the BENNING ST 710 indicates a
-
Please refer to Table 1 for typical resistance values of lines.
01/ 2009
is higher than the admissible limiting value, a
ISO
symbol.
is shown next to the I
next to the R
ISO
symbol.
PE
BENNING ST 710
symbol, if the contact current I
EA
symbol.
EA
.
PE
next to the R
symbol.
PE
<
L-N
appears
is lower than the
or a
is
17