Detecting An Earthing Fault; Lightning Protection; Connecting The Communication Cables - Studer VarioString User Manual

4.4.1 Detecting an earthing fault

The choice of earthing system for the DC circuit is an important factor for the individuals' safety. Once
the decision is made the VarioString can check the continuity of the earth connection.
In case of failure of this connection, the equipment turns off and the LED (3) lights up indicating the
fault. A permanent message (requiring a validation) is displayed on the RCC if present.
The parameters {14040}, {14041} and {14042} allow establishing the type of control to be carried out
or the absence of control as set by default.
4.5 L
IGHTNING PROTECTION
The VarioString has internal protections against lightning by means of surge protection devices. These
devices have an energy dissipation capacity limited to 3,5kA (8x20 µs) which guarantees a certain
protection level but are not a total protection against lightning. According to the installation site, it is
highly recommended to develop a protection strategy specific to your installation. The strategies
depend on various factors specific to each site; therefore we recommend a professional approach
to this issue.
Damages due to lightning often generate significant costs (replacement of all electronics)
which are not covered by the manufacturer's warranty.
4.6 C
ONNECTING THE COMMUNICATION CABLES
The VarioString is fitted with 2 connectors RJ45/8 (8) (see chap. 4.1) that enable to transfer information
via a communication bus to other VarioStrings or to other equipment such as the RCC, the BSP or the
Xcom having the proprietary protocol of Studer Innotec. In this case, the installation should be
stopped and de-energized (the protection devices of power sources and loads should be open) to
complete the cable connection and positioning of the termination switches of all the devices
connected to the communication bus.
The termination switch of the communication bus "Com. Bus" (9) remains in position T
(terminated) except when both connectors are used. In this case and only in this case, the
switch must be placed in the O (open) position. If one of the two connectors is not used,
the termination switch (9) will be in position T.
The max accumulated length of the communication bus is 300m. Due to a line voltage drop, it is
recommended to install only one RCC module at the end of a 300m line or a max of 2 modules at
the end of a 150m line. All the other modules of the system must be placed within the same radius of
a few meters (technical room).
A maximum of 3 RCC-02/03 or Xcom-232i may be connected to the same communication
line with a VarioString.
If a VarioString is connected to another compatible device (Xtender, VarioTrack, BSP, RCC,
Xcom) with the same communication bus, it is highly recommended to make a software
update of all components in the system in order to guarantee all functionalities.
User manual V 1.0
Studer Innotec SA
VarioString
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