Operating Modes
SMA Solar Technology AG
14
SB_SMC_Schueco-BEN093730
User Manual
3.3.5 The green LED goes out briefly
Derating
The "Derating" mode is a normal operating mode which
may occur occasionally and can have several causes:
• Temperature derating
The temperature monitoring of the inverter has reduced the output power to prevent the device
from overheating. The inverter switches to the "Temperature derating" mode. If the Sunny Boy /
Sunny Mini Central frequently switches to this mode, please check the heat dissipation (see
Section 5.1 "Checking Heat Dissipation" (page 27)). For all Sunny Mini Centrals, as well as
the Sunny Boy models SB 3300 / SB 3800, check whether the fans are soiled.
• Current derating
Due to the type of module or the output and wiring of the generator, the PV-side input current
exceeds the maximum possible input current. The inverter switches to the "Current derating"
mode in order to protect itself against overload.
• Output derating
This operating mode only occurs in systems which are operated using the Sunny Mini Central
with integrated SMA Power Balancer set to "PowerGuard".
• Frequency-dependent output derating P(f)
This operating mode occurs when the function which limits active power, P, is activated as a
function of grid
frequency f
AC
.
You will find more detailed information on this function in the installation guide for Sunny Mini
Central 9000TL / 10000TL / 11000TL with Reactive Power Control.
Maintenance and Cleaning of the Fans
The fan cleaning procedure is described in the respective installation guide.
