SMA Sunny Island 5048 Installation Instructions Manual page 116

Relay
The relays are changeover contacts. They have both a break contact as well as a
NO contact.
Except for "Alm" (alarm), all relay functions are listed as NO contact functions, in
other words, the contact is closed if the relay is activated by selecting the function.
For the exception "Alm", the relay has a break function. This means that the relay
is normally activated and opens the contact. It is only deactivated when a fault
occurs and then closes the contact (and thus activates a warning light, for
example).
In case of a fault, the relays go into the safe mode, that means they deactivate.
Page 116 SI5048-11:EE4206
SMA
Technologie AG
Technical Description