SMA WB 3000-21 Installation - Manual (Page 22)

4 Product Description SMA Solar Technology AG
22 WB3-5TL-21-IA-en-10 Installation Manual
4.10 SMA Grid Guard
SMA Grid Guard acts as an automatic disconnection device between a grid-parallel generator
(e.g. a PV plant or small wind turbine system) and the power distribution grid.
Furthermore, SMA Grid Guard is a grid monitoring concept which detects errors by permanently
monitoring grid impedance, line voltage and power frequency. For example, SMA Grid Guard
detects when a stand-alone grid is formed and immediately disconnects the inverter from the power
distribution grid.
In some countries, the connection conditions require a device which protects grid-relevant operating
parameters against unpermitted changes. SMA Grid Guard assumes this function and protects the
setting of the country data set after the first 10 feed-in hours. After the first 10 feed-in hours the country
data set can only be changed using a communication product and after a personal access code has
been entered, the SMA Grid Guard code. You can obtain the SMA Grid Guard code from
SMA Solar Technology AG (for application for the SMA Grid Guard code, see certificate
"Application for SMA Grid Guard-Code" at www.SMA-Solar.com).