SMA SB 3000TL - Manual (Page 24)

6.3 AC Connection
6.3.1 Requirements for the AC Connection
Cable requirements:
☐ External diameter: 12 mm to 21 mm
☐ Conductor cross-section: 1.5 mm² to 10 mm²
☐ Insulation stripping length: 12 mm
☐ The cable must be dimensioned in accordance with the local and national directives for the
dimensioning of cables. The requirements for the minimum wire size derive from these
directives. Examples of factors influencing cable dimensioning are: nominal AC current, type of
cable, routing method, cable bundling, ambient temperature and maximum desired line losses
(for calculation of line losses, see the design software "Sunny Design" from software
version 2.0 at www.SMA-Solar.com).
Load-break switch and cable protection:
Damage to the inverter due to the use of screw-type fuses as load-break switches
Screw-type fuses (e.g. DIAZED fuse or NEOZED fuse) are not load-break switches.
• Do not use screw-type fuses as load-break switches.
• Use a load-break switch or circuit breaker as a load disconnection unit (for information and
design examples, see the Technical Information "Circuit Breaker" at www.SMA-Solar.com).
☐ In PV systems with multiple inverters, protect each inverter with a separate circuit breaker.
Make sure to observe the maximum permissible fuse protection (see Section 11 "Technical
Data", page 47). This will prevent residual voltage being present at the corresponding cable
after disconnection.
☐ Loads installed between the inverter and the circuit breaker must be fused separately.
Residual-current monitoring unit:
☐ If an external residual-current device is required, install a residual-current device which trips at
a residual current of 100 mA or higher (for details on selecting a residual-current device, see
the Technical Information "Criteria for Selecting a Residual-Current Device" at www.SMA-
Solar.com).
Overvoltage category:
The inverter can be used in grids of overvoltage category III or lower in accordance with
IEC 60664-1. That means that the inverter can be permanently connected to the grid-connection
point of a building. In case of installations with long outdoor cabling routes, additional measures to
reduce overvoltage category IV to overvoltage category III are required (see the Technical
Information "Overvoltage Protection" at www.SMA-Solar.com).
6 Electrical Connection SMA Solar Technology AG
Operating Manual SB30-50TL-21-BE-en-11 24