SMA WINDY BOY 3300 - Red LED Is Permanently on; Checking the Small Wind Turbine System for Earth Faults

Troubleshooting SMA Solar Technology AG
62 WB33-38-IA-IEN120940 Installation Manual
9.3 Red LED is Permanently On
If the red LED is permanently on during operation, this points either to an earth fault in the system or
at least one of the overvoltage protection varistors being defective.
In deliberately earthed systems, the red LED lights up as soon as the inverter has been commissioned.
However, this has no impact on the function of the inverter. Before you check the small wind turbine
system for an earth fault, check whether deliberate earthing has been carried out.
In deliberately earthed small wind turbine systems, check from time to time that the varistors in the
inverter are working properly, since a varistor fault can no longer be displayed.
9.3.1 Checking the Small Wind Turbine System for Earth Faults
1. Wait until LEDs have gone out.
2. Use a current probe to make sure no current is
present in the DC cables.
☑ If current is present, check the installation.
DANGER!
Danger to life due to high voltages in the inverter
• Stop the small wind turbine system and secure against restarting.
• Disconnect the miniature circuit-breaker and secure against accidental or inadvertent
reconnection.
DANGER!
Danger to life due to high voltages in the inverter
The capacitors in the inverter take 15 minutes to discharge.
• Wait 15 minutes before opening the inverter.