Drastic change of differential current – SMA SB 3300TL User Manual
Page 25

SMA
Technologie AG
Device Description
Operating Instructions
SB3300TL-11:FE1905
Page 21
Drastic Change of Differential Current
When the failure occurs, the yellow failure LED is on for five seconds and then starts
the blinking code by staying off for three seconds and then blinking seven times in
short intervals. The code is sent three times. If the failure persists, the signal starts from
the beginning.
The Sunny Boy 3300TL detected a drastic change of differential current and immedi-
ately interrupted its connection to the grid. The all-pole sensitive differential current
monitoring integrated in the inverter monitors the discharge current to ground from
the grid connection of the inverter to the PV-generator. This additional personnel safe-
ty concept reacts to a change of differential current of IDN > 30 mA and disconnects
the inverter from grid within 0.2 seconds.
5 s
3 s
1 s
1 s
1 s 1 s 1 s 1 s
LED on
LED off
Yellow LED is blinking 7
times in short intervals.
The signal is repeated 3 times and
then starts from the beginning.