INSTALLATION, USE AND
MAINTENANCE
SUNWAY STRING BOX
LT 1500V 24 INPUTS
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Prohibition
It is strictly prohibited to operate inside the SUNWAY STRING BOX LT 1500V to
carry out short circuit tests concerning the strings.
Any system testing must be carried out on the individual strings only once that
have been disconnected from the product.
2.3. Intended Use
The SUNWAY STRING BOX LT 1500V products constitute a modular system for creating parallel strings
for PV modules.
The product envisages an output on-load disconnector which is capable of cutting off the connection of the
PV field subsection.
Observe the maximum operating voltage indicated in the product technical characteristics found in section
The product must only be used as prescribed in this manual. The DC power supply must come from the PV
field only.
Any use other than that described in this manual is to be considered inappropriate and therefore improper.
2.4. Qualified Technical Personnel
All work on SUNWAY STRING BOX LT 1500V products must be carried out by skilled technical personnel
only. By skilled personnel it is intended persons who have been suitably trained to carry out the work in
question.
To commission and use the SUNWAY STRING BOX LT, personnel must know and understand the
instructions for installation and use. In particular, all safety warnings must be strictly observed.
2.5. Specific Dangers Linked to Photovoltaic (PV) Systems
PV systems have certain characteristics which are the source of additional hazards and are described
below:
•
A live current source is connected. Depending on the operating conditions, there may be live voltage
from the PV generator or from the electrical grid. This must be taken into consideration, particularly when
disconnecting parts from the system.
•
Very high DC voltages are involved (with no periodic zero crossings) hence failure or the incorrect use
of fuses or plugs may cause electric arcs.
•
The short-circuit current of the PV generator is only slightly higher than the maximum operating current
and furthermore is linked to radiation. This means that fuses may not always blow in the event of a short-
circuit.
•
The PV generator grid is usually an IT type, i.e. it is only earthed in the event of a fault or energy leakage.
For connection to PV fields with earthing pole, connection is of the TN type, but the earth connection is
protected by a fuse which may trip in the event of a single fault.
•
In the event of a fault (for example a short-circuit), cutting off a generator with a high number of branches
may prove to be somewhat difficult. Take great care to ensure each sub-field disconnect switch has been
opened before going near the devices installed in the technical room.
2.6. Personal Protective Equipment
Maintenance technicians must be provided with the following personal protective equipment as envisaged
by European Directives and relative implementation of the same on national territory.
SYMBOL
DESCRIPTION
Safety glasses/face shield
Throughout operations
