Testing Of Devices Of Protection Class Ii - Benning ST 725 Notice D'emploi

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.
- For mains operating mode (contact current by means of the direct measurement method,
test object in operation!): Connect the plug of the mains connection cable with the socket K
and the shock-proof plug with a protected shock-proof socket (230 V, 50 Hz, 16 A).
- If necessary, the testing voltage of the R
reduced to 250 V
on the display 8 . Press the key again to switch back to the preset testing voltage of 500 V
- 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
6 kΩ).
- If "HIGH LOAD" is shown on the display, this indicates an excessive load (R
(I ) > 16 A) of the test object. There might be danger of a m short-circuit or of an earth
LOAD
fault. Check whether there is a short-circuit between the external conductor (L) and neutral
conductor (N) of the test object.
- If there is no short-circuit, you can continue with the testing procedure by pressing the

-key 3 .
- If the insulating resistance R
next to the R
ISO
BENNING ST 725 in mains operating mode:
- The BENNING ST 725 interrupts the testing procedure after the R
measurement and requests the user to switch the mains voltage of 230 V to the test socket
1 by showing a flashing "I
press the -key 4 to measure the contact current I
- The contact current by means of the direct measurement method only starts as soon as the
mains voltage is correct applied.
07/ 2018
by means of the
DC
is higher than the admissible limiting value, a
ISO
symbol.
" symbol. Make sure that the test sample is protected and
LEAK
BENNING ST 725
(shock-proof) and of devices of protection

(insulating resistance) measurement can be
ISO
-key 5 . The selected testing voltage is briefly shown
(direct measurement method).
LEAK
<< 14 Ω, I
L-N
appears
(insulating resistance)
ISO

.
DC
>
L-N
LAST
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