SMA MULTICLUSTER BOX 12 - Manual (Page 45)

SMA Solar Technology AG 13 Multicluster Technology Terms
Operating Manual MC-BOX-12-3-20-BE-en-10 45
Main cluster
The main cluster is the leading cluster within a Multicluster system. The master of the main cluster is the central user
interface for the main cluster and all extension clusters of a stand-alone grid. The master of the main cluster is superior to
the masters of the extension clusters. The tasks performed by the master of the main cluster include the following:
• Starting and stopping the multicluster system
• Controlling and monitoring the masters of the extension cluster
• Communicating with the Multicluster Box
If the master of the main cluster stops operation, the entire multicluster system shuts down. If a diesel generator is
integrated in the stand-alone grid, it will take over the power supply to the loads in this case.
Extension cluster
An extension cluster is a cluster within the multicluster system which is subordinated to the main cluster.
The master of the extension cluster follows the instructions issued by the master of the main cluster. The master of the
extension cluster sends the operating data of its cluster to the master of the main cluster. If the master of an extension
cluster stops operation, then only this cluster shuts down. In this case, the multicluster system continues to operate with
reduced power.