SMA SUNNY TRIPOWER X 20-US - Electrical Connection; Requirements for the Electrical Connection; Permitted Grid Configurations; Residual-Current Monitoring Unit

6 Electrical Connection
SMA Solar Technology AG
Operating manualSTPxx-US-50-BE-en-1136
6 Electrical Connection
6.1 Requirements for the electrical connection
6.1.1 Permitted grid configurations
The inverter approved for operation in the following utility grids:
• 480V / 277V WYE
6.1.2 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 of type A and B that have a rated
residual current of 100mA or higher. Each inverter in the system must be connected to the
utility grid via a separate residual-current device.
6.1.3 Load-break switch and cable protection
☐ In PV systems with multiple inverters, protect each inverter with a separate three-phase circuit
breaker. Make sure to observe the maximum permissible fuse protection (see Section14,
page94). 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.
☐ The load-break switch or circuit breaker must be suitable listed (see National Electrical Code
®
ANSI/NFPA 70) or Canadian Electrical Code
®
CSA C22.1).
☐ The overcurrent protective device for the AC output circuit is to be provided by others.
6.1.4 Requirements on the AC conductors
☐ Conductor type: copper wire
☐ The conductors must be solid or fine-stranded. When using fine-stranded wire, bootlace
ferrules can be used.
☐ Conductor cross-section: 10mm² to 16mm² (8AWG to 6AWG)
☐ Insulation stripping length: 18mm to 20mm (0.71in to 0.79in)
☐ The conductors with regards to its ampacity, rated temperatures, operating conditions and its
power loss must be made in accordance with the local standards and the National Electrical
Code
®
ANSI/NFPA 70 or the Canadian Electrical Code
®
CSA C22.1.
Also see:
• Connecting the AC conductors⇒page40
6.1.5 Network cable requirements
The cable length and quality affect the quality of the signal. Observe the following cable
requirements:
☐ Cable type: 100BaseTx