7 Electrical Connection
SMA Solar Technology AG
Operating manual
SB55-LV-JP-41-BE-en-13
27
Grounding cable requirements:
Use of fine-stranded conductors
You can use an inflexible or a flexible, fine-stranded conductor.
• When using a fine-stranded conductor, it has to be double crimped by a ring terminal lug.
Make sure that no insulated conductor is visible when pulling or bending. This will ensure
sufficient strain relief by means of the ring terminal lug.
☐ Grounding cable cross-section: max. 8 mm²
Load-break switch and cable protection:
NOTICE
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 suitable as load-break switches.
• Do not use screw-type fuses as load-break switches.
• Use a load-break switch or a circuit breaker for load disconnection.
☐ 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 14 "Technical
Data", page 89). This will prevent residual voltage from 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:
The inverter does not require an external residual-current device when operating. If local
regulations require the use of a residual-current device, the following must be observed:
☐ The inverter is compatible with residual-current devices that have a rated residual current of
30 mA or higher. Each inverter in the system must be connected to the utility grid via a
separate residual-current device.
7.2.2
Connecting the Inverter to the Utility Grid
Requirements:
☐ The connection requirements of the grid operator must be met.
☐ The grid voltage must be within the permissible range. The exact operating range of the
inverter is specified in the operating parameters.
Procedure:
1. Disconnect the circuit breaker and secure it against reconnection.
2. Dismantle the AC cable by 50 mm.
