Huawei Proprietary and Confidential                                     
Copyright © Huawei Technologies Co., Ltd. 
 
8.3 Troubleshooting 
This section describes troubleshooting measures for common fault alarms in the SUN2000. 
Alarms range in severity according to the following definitions: 
 
Major: The fault causes the SUN2000 to enter the shutdown mode and stop feeding 
electricity to the power grid. 
 
Minor: Some components are faulty but the SUN2000 can still feed electricity to the 
power grid. 
 
Warning: The SUN2000 output power decreases due to external factors. 
Table 8-2 lists the measures taken to rectify common fault alarms in the SUN2000. 
Table 8-2 Troubleshooting 
Too many PV modules 
connected in series lead to 
excessively high PV string 
output voltage, making the PV 
string open-circuit voltage 
greater than the maximum 
operating voltage of the 
SUN2000. 
Check whether too many PV 
modules are connected in series, 
making the PV string open-circuit 
voltage greater than the maximum 
operating voltage of the SUN2000. 
If so, reduce the number of PV 
modules connected in series until the 
PV string output voltage drops to the 
specified range for the SUN2000. 
After the adjustment, the SUN2000 
will work properly. 
 
PV strings have been 
shielded for a long time. 
 
PV strings have 
deteriorated. 
a.  Check whether the output current 
of a PV string is obviously less 
than the output current of other 
PV strings. 
b.  If so, check whether the PV 
string is shielded. 
c.  If the PV string is clean of 
contaminants and not shielded, 
check whether the PV modules 
are faulty. 
The cables between PV strings 
were connected in reverse 
during SUN2000 installation. 
Check whether the cables between 
PV strings are correctly connected. 
If they are connected in reverse, 
reconnect the cables.