Testing Of Devices Of Protection Class Ii - Benning ST 725 Bedienungsanleitung

step 2 of 2:
- If the protective conductor current is lower than the admissible limiting value, a
shown next to the I
- The overall test is considered to be passed, if "PASS" is shown on the display.
As an alternative:
BENNING ST 725 in battery operating mode (without mains supply):
- Similarly, a
ternative leakage current measurement method) is lower than the admissible limiting value.
- The test is considered to be passed, if "PASS" is shown on the display.
See figure 4: T esting of devices of protection class I (devices with protective conductor and
accessible conductive parts which are connected to the protective conductor)
Note on measuring the protective conductor resistance:
- Alternatively, the measurement of the protective conductor resistance R
as permanent measurement (max. 2 x 90 seconds). For this purpose press the key 2 for
approx. > 5 seconds until the  symbol appears on the display. Check the connecting line of
the test object by bending it over the entire length in order to detect weak points or a break of
the protective conductor. The BENNING ST 725 continuously records the current measured
value on the display and stores the maximum value in the memory. By pressing the key
2 again, the measurement is carried out with reversed polarity. Press the key 2 again to
indicate the maximum value of R
described in section 9.1.
Note on measuring the protective conductor current in mains operating mode:
- Alternatively, the measurement of the protective conductor current I
out as permanent measurement (max. 2 x 5 minutes). Press the key 4 for approx. > 5
seconds to start permanent measurement. After 5 minutes, the polarity of the mains voltage
will be reversed automatically ("L/N" - "N/L"). By pressing the key 4 earlier, the mains
voltage polarity reversal can be activated manually and by pressing the key 4 again, the
measurement can be stopped.
Please observe that the BENNING ST 725 is not designed for carrying out repeated
permanent measurements at a high load current. If the admissible internal operating
temperature is exceeded, the "StOP" and "hot" symbols will be shown on the display. In this
case, the BENNING ST 725 must be disconnected from the mains and can be used again
after a sufficient cooling phase.
Note on measuring the contact current:
- Accessible conductive parts which are not connected with the protective conductor have to
be tested as described in section 9.2. For measuring the contact current (direct measurement
method), the BENNING ST 725 has to be operated with a mains voltage of 230 V.
- During contact current measurement by means of the direct measurement method, no part
of the test object must have a connection to the earth potential. The test object must be
placed onto an insulated surface. Otherwise, leakage currents to earth might influence the
measuring result.

9.2 Testing of devices of protection class II


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 725.
- Establish a connection between the 4 mm test socket 9 and a metal part of the test object
by means of the test lead with alligator clip.
09/ 2014
symbol.
LEAK
will be shown next to the I
PE
BENNING ST 725
symbol, if the protective conductor current I
EA
on the display and to continue the testing procedure as
 (shock-proof) and of devices of protection

will be
(al-
EA
can be carried out
PE
can be carried
LEAK
29