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:

• In PV systems with multiple inverters, protect each inverter with a separate circuit breaker. Make sure to observe the maximum permissible fuse protection ( > Technical Data). 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).

Grounding conductor monitoring:

The inverter is equipped with a grounding conductor monitoring device. This grounding conductor monitoring device detects when there is no grounding conductor connected and disconnects the inverter from the utility grid if this is the case. Depending on the installation site and grid configuration, it may be advisable to deactivate the grounding conductor monitoring. This is necessary, for example, in an IT system if there is no neutral conductor present and you intend to install the inverter between two line conductors. If you are uncertain about this, contact your grid operator or SMA Solar Technology AG.

• Grounding conductor monitoring must be deactivated after initial start-up depending on the grid configuration ( > Deactivating Grounding Conductor Monitoring).

Safety in accordance with IEC 62109 when the grounding conductor monitoring is deactivated

In order to guarantee safety in accordance with IEC 62109 when the grounding conductor monitoring is deactivated, carry out one of the following measures:

1. Connect a grounding conductor made of copper wire with a cross-section of at least 10 mm² to the connecting terminal plate for the AC cable.
2. Connect additional grounding with the same cross-section as the connected grounding conductor to the connecting terminal plate for the AC cable ( > Connecting Additional Grounding). This prevents touch current if the grounding conductor at the connecting terminal plate for the AC cable fails.

Connection of additional grounding

In some countries, additional grounding is generally required. In each case, observe the locally applicable regulations.

1. If additional grounding is required, connect an additional grounding with the same cross-section as the connected grounding conductor to the connecting terminal plate for the AC cable ( > Connecting Additional Grounding). This prevents touch current if the grounding conductor at the connecting terminal plate for the AC cable fails.