SMA SUNNY ISLAND 5048-US - Page 210

Troubleshooting SMA America, LLC
210 SI5048U-TUS121440 Technical Description
Why does the ”VAC-Low” error (output voltage too low) also occur when the
Sunny Island is started?
• A permanent short-circuit exists in the off-grid power system. Check the AC output connections
of the off-grid power system (see section 6.3”AC Connection” (page46)).
• The loads connected to the off-grid power system are too heavy. The power/electrical energy
of the Sunny Island is not sufficient to supply the loads. Switch off some of the loads and restart
the Sunny Island.
Why is the off-grid frequency not at 60 Hz?
• The Sunny Boy inverter is controlled via the frequency (see section 17.5”Frequency Shift Power
Control (FSPC)” (page147)).
• The ”AFC” function of the Sunny Island 5048U is activated (see section 12.6”Automatic
Frequency Control (AFC)” (page104)).
• Power fluctuations cause frequency deviations.
What do I do when a battery cell can no longer be used?
• Remove the unusable cell from your battery bank. Start the Sunny Island and change the battery
voltage in the QCG under ”New Battery”.
What can I do when the QCG does not run?
• Switch off the Sunny Island (see section 9.3”Switching off” (page74)) and restart it (see
section 9.1”Switching on” (page72)).
What happens when ”MMC operation failed” is displayed?
• You wanted to perform an action using the SD card, but it failed (see section 10.9”Display of
Warnings and Failures” (page91)). Check the card (on your PC/laptop) and use a new SD
card, if necessary.
Why does my Sunny Island stay on even though I switched the DC circuit breaker
to Off?
• Your Sunny Island may be powered by the AC side. Switch off all AC loads and disconnect
them from the Sunny Island (see section 9.4”Disconnecting the Device from Voltage Sources”
(page74)).
Why is my battery discharging even though the generator is running?
• The power produced by the generator does not reach the Sunny Island. Check the voltage and
frequency values. The fuses on the generator may have been triggered.
• The consumer power exceeds the generator power ”234.03 GnCurNom”.
– Check error messages Find the cause.
Why is the deactivation defined by the SOC in case of a full or equalization
charge and generator start in the second time zone?
• Equalization charge has a higher priority than silent time.