R&S ENV432
Preparing for Use
User Manual 1326.6492.04 - 03
E-14
4.3 Protective Earthing
Electric shock due to faulty protective earthing.
By design, V-networks feature a nonstandard isolation and no fuse in the measuring
circuit, but may exhibit high ground leakage currents. To protect users against touching
live conductive parts, provision of a protective earthing for this V-network must be
ensured by qualified electrical specialists. The applicable national regulations and
standards must be observed as part of the installation process.
Due to the V-network's operating principle, high leakage currents of approx. 1200 mA
are applied to the housing. The housing of the V-network is applied to the AC supply
voltage at relatively low impedance. For this reason, the V-network must always be
connected to the protective earth prior to putting it into operation.
In case of flexible cable connection, it is necessary to assume that the protective earth
conductor connection can come loose. Prior to putting the V-network into operation, it
must be connected using an additional protective earth conductor in line with VDE
0100-540 Part 5-54 (IEC 60364-5-54) with cross-sectional area of 6 mm
2
between a
protective earth terminal in the test room and the protective earth conductor terminal
(
) on the rear panel of the R&S ENV432. In this manner, the housing voltage will
remain under 4 V even in case of a faulty EUT, i.e. in the event of a short circuit.
Only then may the V-network be connected to the mains supply. Removal from service
must be performed in the reverse order: First disconnect the V-network from the mains
supply and only then disconnect the additional protective earth conductor connection.
Make sure that the RF reference ground is not impacted by disturbance voltages (e.g.
from an industrial network) when the protective earth terminal is connected to the
protective earth. If this is the case, the protective earth must be connected via a
protective earth choke. With the choke, make sure that no voltages constituting a
shock hazard are applied to the housing.
If "electrical separation" is used as a protective measure, an electrical specialist must
decide at which points a ground connection or a connection to the protective ground
terminal available on site may be made.
The protective earth connection must not be removed until all connections have been
disconnected from the mains supply. All safety instructions and warnings given on the
device and in this user manual must be strictly observed.
