SMA AUTOMATIC SWITCH BOX M-20 - Manual (Page 47)

SMA Solar Technology AG 6 Commissioning
Installation Guide AS-BOX-M_L-IA-IEN110320 47
6.2 Dimensioning the thermal fuse for the generator
Selectivity of the thermal fuse:
In unfavorable constellations e.g. the same fuse value is connected twice in a row, it may be
impossible to achieve selectivity between the lead fuses to be inserted and the upstream or
downstream fuses. This is unavoidable due to the complexity of the Backup system with several
feeding sources.
• Dimension the thermal fuse in accordance with the requirements of the generator.
• If you use the Automatic Switch Box M, insert a fuse link with maximum rated current of 40 A
into the fuse-switch-disconnector "1_1-F6". Use a fuse link of the size D02.
Hint: a fuse link of the size D02 with a rated current of 40 A and appropriate headed sleeves
are included in the scope of delivery.
• If you use the Automatic Switch Box L, insert a fuse link with maximum rated current of 50 A into
the fuse-switch-disconnector "1_1-F6". Use a fuse link of the size D02.
Hint: a fuse link of the size D02 with a rated current of 50 A and appropriate headed sleeves
are included in the scope of delivery.