Power Supply of Backup Loads in Parallel Grid Operation

In parallel grid operation, the backup loads can be supplied from the utility grid as long as the amperage and voltage of the backup loads' circuits are within the permitted range.

If the current exceeds 20 A, a Smart Connected message is sent in any case. If the current exceeds 22 A, the contactor between the backup loads and the utility grid is opened after a tripping time that depends on the level of the current. The contactor is then automatically tested. If the test is successful, the contactor is closed again and the backup loads can continue to be supplied from the utility grid.

Behavior of the contactor between the AC backup terminal and the connection to the utility grid at increased current

If the voltage of the electrical circuits of the backup loads is not in the permitted range between 170 V and 277 V, the contactor opens. In order for the contactor to close again, the voltage must be in the permitted range for at least 20 s.

Behavior of the contactor between the AC backup terminal and the connection to the utility grid when the voltage is too high or too low