INSTALLATION, USE AND
MAINTENANCE
SUNWAY STRING BOX
LT 1500V 24 INPUTS
Rev. 02 - Error! Unknown document property
name.
32 / 43
10. TROUBLESHOOTING
The SUNWAY STRING BOX LT 1500V products are completely protected against short-circuits and
overvoltage caused by system failure or temporary phenomena. Furthermore, the control system performs
complete self-diagnosis operations to help personnel solve any problems which may occasionally arise. The
modular design of Enertronica Santerno inverters makes repair and/or reset operations quick and easy to
perform.
This chapter indicates the most likely causes of the most common problems. The steps to be taken to
remove these causes are also described.
WARNING
To carry out the following operations, check that the parallel string box is in
safety conditions. Please refer to section 2.8.
NOTA
If necessary, please contact the Enertronica Santerno SpA CUSTOMER SERVICE.
10.1. General Principles in the Event of Failure
Access to the PV system components for the purpose of maintenance, modifications and management
involves all persons responsible for production and maintenance. It must be carried out in observance of
the health and safety regulations described in section 0.
10.1.1. Fault Containment
The following prescriptions are of a general nature.
•
Place the equipment affected by the fault in safety conditions. This operation may involve stopping and
disconnecting all the up- and downstream devices. Please refer to section 2.5.
•
If the fault has occurred inside an inverter, press an emergency stop button to cut the inverter off up- and
downstream. Open the switch disconnectors of all the string boxes so that the entire DC input section
is safe, including the DC-Parallel (if installed).
•
In multi-inverter systems it is usually sufficient to cut off the inverter affected by the fault both up- and
downstream so that the other inverters can remain in operation.
•
If the fault has occurred in one of the components downstream from the inverter (AC parallel cabinet,
external transformer, metering cabinet etc.) STOP all the machines and then press the emergency stop
button to cut off the inverter both up- and downstream.
•
If the fault has occurred in one of the components upstream from the inverter (DC-parallel, String Box,
etc.) STOP all the machines and then press the emergency stop button to cut off the inverter both up-
and downstream. Open the disconnect switch disconnectors of all the String Boxes so that the entire
DC input section is safe, including the DC-Parallel (if installed).
•
If the fault has occurred in one of the String Boxes, open all the strings connected in input and open the
disconnect switch disconnectors of all the String Boxes connected at the same inverter of DC-Parallel
of the faulty String Box, in order to place all the equipment in safety conditions, including the cable
output section. If is not possible to open the strings because there is current flowing in the relative
cables, wait the absence of solar radiation to open the strings of faulty string box.
•
Proceed with analysis of the causes and consequences of the fault.
10.2. Fault Analysis
This section covers the main principles to be observed when analysing the causes and consequences of
faults.
A PV inverter usually operates as part of an overall system. All the components adopt various protective
measures therefore, in general, the consequences of a generic fault affecting an upstream component or
element does not extend to other components downstream.
However, the causes and the consequences of any faults which may arise need investigating on the plant
as a whole.
Fault investigation and analysis activities represent one of the most hazardous tasks assigned to
maintenance technicians. This manual only provides indications of an extremely generic nature concerning
