R&S ENV4200
Preparing for Use
User Manual 1107.2470.12 - 03
E-14
4.3 Protective Earthing
Electric shock due to incorrect protective earthing.
Due to the design, V-networks do not have standard-compliant insulation, do not have
a fuse in the measuring circuit and exhibit high leakage currents. In order to protect the
user from contact with electrically live instrument parts, the protective earthing of this
V-network must be made by experienced electrically skilled personnel. 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 up to 3 A 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.
It must be assumed that, when connecting with a flexible cable, the ground wire
connection can come loose. Before commissioning, the V-network must therefore be
connected with an additional protective earth conductor according to VDE 0100-540
part 5-54 (IEC 60364-5-54) with a sufficient cross section of 6 mm
2
between the
protective earth-connection of the measurement room and the rear panel protective
conductor terminal
(
) of the R&S ENV4200, so that even in the case of a faulty device under test, i.e.
in the event of a short circuit, the housing voltage is below 4 V.
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 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 PE
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 earth
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 operating manual must be strictly observed.
