Testing Procedure - Benning ST 720 Bedienungsanleitung

- If the voltage potentials are within the following limiting values, there will be a
"LN", "LE" and "NE" symbols.
LN
LE
NE
Only the voltage potentials between the individual connections L, N and PE are
measured. The measurement does not provide any information on the proper

installation of the shock-proof socket. There will be no warning in case of a
dangerous contact voltage of the PE conductor!
The BENNING ST 720 must not be permanently connected to the mains voltage!
- After approx. 3 seconds, the BENNING ST 720 automatically switches to stand-by mode.
See figure 3:
8.1.3

Testing procedure

The BENNING ST 720 is intended for electrical safety tests according to DIN VDE 0701-0702
and ÖVE/ ÖNORM E 8701. Please refer to the current version of the standards for detailed
information concerning the tests and limiting values.
Automatically, the BENNING ST 720 verifies the type of the connected test object and informs
the user in case of incorrect preselection of the testing procedure [ 2 ... 3 ].
Note:
- The BENNING ST 720 can be used for tests in battery operating mode and in mains oper-
ating mode with connection of a mains voltage of 230 V. In battery operating mode, it has
to be observed that the protective conductor current and contact current measurement is
carried out by means of the alternative leakage current measurement method. This method
is appropriate for test objects which do not contain any mains voltage-dependent switching
elements (e.g. mains supply units).
- If the internal structure of the test object is not known or if it contains mains voltage-depend-
ent switching elements, the test has to be carried out in mains operating mode with connec-
tion of a mains voltage of 230 V. As soon as the BENNING ST 720 is supplied with mains
voltage via the jack K, the protective conductor current/ contact current measurement will
be carried out automatically by means of the differential current/ direct measurement method
under operating conditions of the test object.
- The testing voltage for insulating resistance measurement is preset to 500 V
to the applicable standard. For test objects with integrated overvoltage arresters and for
electronic devices for which there are objections regarding a testing voltage of 500 V
testing voltage can be reduced to 250 V
8.2 Testing of electrical devices / equipment according to DIN VDE 0701-0702 and ÖVE/
ÖNORM E 8701
Prior to test, a visual inspection of the test object has to be carried out. In case

of possible damages, the test must be stopped.
8.2.1 Testing of devices of protection class I
Testing of devices with protective conductor and accessible conductive parts which are con-
nected to the protective conductor.
- Connect the test object to the test socket 1 of the BENNING ST 720.
- Plug the 4 mm safety plug of the test cable with alligator clip into the 4 mm safety socket 9
and establish a connection with a metal part of the test object.
- For mains operating mode (protective conductor current by means of differential current
measurement method, test object in operation!): Connect the plug of the mains connec-
tion 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
08/ 2010
195 V - 253 V
195 V - 253 V
< 30 V
Voltage measurement on external shock-proof socket
by means of the
DC
BENNING ST 720
or
or
by means of the
DC
(insulating resistance) measurement can be
ISO
-key 5 . The selected testing voltage is briefly shown
LN 195 V - 253 V
LE < 30 V
NE 195 V - 253 V
DC
-key 5 .

next to the
according
, the
DC
22