Electrical Connection; Requirements For The Electrical Connection; Permitted Grid Configurations; Residual-Current Monitoring Unit - SMA SUNNY TRIPOWER X 20-US Operating Manual

6 Electrical Connection

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
☐ 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
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
36 STPxx-US-50-BE-en-11
®
CSA C22.1).
®
CSA C22.1.
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