Huawei SUN2000 Series User Manual page 63

SUN2000-(20KTL, 29.9KTL, 30KTL, 36KTL, 40KTL)-
M3
User Manual
ID Name
2011 String
reverse
connecti
on
2012 String
current
backfeed
2021 AFCI
self-
check
failure
2031 Phase
wire
short-
circuited
to PE
2032 Grid loss
Issue 01 (2020-10-15)
Severity Cause
Major The PV string polarity is
reversed.
Cause ID 1–8: PV strings 1–
8
Warning The number of PV modules
connected in series to the
PV string is insufficient. As
a result, the terminal
voltage is lower than that
of other strings.
Cause ID 1–8: PV strings 1–
8
Major Cause ID = 1, 2
The AFCI self-check fails.
Major Cause ID = 1
The impedance of the
output phase wire to PE is
low or the output phase
wire is short-circuited to PE.
Major Cause ID = 1
● Power grid outage
occurs.
● The AC circuit is
disconnected or the AC
switch is off.
Copyright © Huawei Technologies Co., Ltd.
8 Maintenance
Solution
Check whether the PV string is
reversely connected to the
inverter. If yes, wait until the
solar irradiance declines at night
and the PV string current drops
to below 0.5 A. Then, turn off
the two DC switches and correct
the PV string connection.
1. Check whether the number of
PV modules connected in
series to the PV string is less
than that of other PV strings.
If yes, wait until the PV string
current drops below 0.5 A,
turn off all DC switches, and
adjust the number of PV
modules in the PV string.
2. Check whether the open-
circuit voltage of the PV
string is abnormal.
3. Check whether the PV string
is shaded.
Turn off the AC output switch
and DC input switch, and then
turn them on after 5 minutes. If
the alarm persists, contact
Huawei technical support.
Check the impedance of the
output phase wire to PE, locate
the position with low
impedance, and rectify the fault.
● The alarm is cleared
automatically after the power
grid recovers.
● Check whether the AC circuit
is disconnected or the AC
switch is off.
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