Connecting the Battery Fuse to the Sunny Island
Qualified person
Selecting the battery fuse
The battery fuse safeguards the DC connection of the inverter against an overload caused by the battery. The battery fuse and the cabling with battery and inverter must be sized in accordance with the technical data of the DC connection ( > DC Connection for Battery).
Tip: Install a battery fuse of the type enwitec BAT FUSE B-01 or enwitec BAT FUSE B-03.
Maximum cable length for the DC connection
Long cables and insufficient conductor cross-sections reduce the efficiency of the system and the overload capacity of the inverter.
- The length of all DC cables from the battery via the battery fuse to the Sunny Island must be smaller than 10 m.
The recommended minimum conductor cross-section depends on the battery voltage, the power and the length of the cable:
Cable requirements when using the inverter with an enwitec BAT FUSE B-01 or enwitec BAT FUSE B-03 battery fuse:
Sunny Island | Cable length* | Conductor cross-section | Cable diameter | Terminal lug |
|---|---|---|---|---|
SI8.0H | ≤ 5 m | 70 mm² | 14 mm to 25 mm | M8, 20 mm to 25 mm wide |
> 5 m | 95 mm² | 14 mm to 25 mm | M8, 20 mm to 25 mm wide | |
SI6.0H | ≤ 5 m | 50 mm² | 14 mm to 25 mm | M8, 20 mm to 25 mm wide |
> 5 m | 70 mm² | 14 mm to 25 mm | M8, 20 mm to 25 mm wide | |
SI4.4M | ≤ 5 m | 50 mm² | 14 mm to 25 mm | M8, 20 mm to 25 mm wide |
> 5 m | 70 mm² | 14 mm to 25 mm | M8, 20 mm to 25 mm wide |
* Cable length from the battery to the Sunny Island via the fuse switch-disconnector
WARNING
Danger to life due to incompatible lithium-ion battery
An incompatible lithium-ion battery can lead to a fire or an explosion. With incompatible lithium-ion batteries, it is not ensured that battery management is intrinsically safe and will protect the battery.
- Ensure that the lithium-ion batteries are approved for use with the Sunny Island (see technical information “List of Approved Batteries” at www.SMA-Solar.com).
- If no lithium-ion batteries approved for the inverter can be used, lead-acid batteries can be used.
- Verify that the battery complies with locally applicable standards and directives and is intrinsically safe.
Procedure:
- Ensure that the load-break switch of the battery fuse is open and secured against reconnection.
- On the Sunny Island, remove all screws of the lower enclosure lid using an Allen key (AF 5) and remove the enclosure lid. Retain the screws and conical spring washers for later use.
- Connect the DC power cable of the battery fuse with the correct polarity ( > Connecting the DC Power Cable).