SMA SC 500HE-20 Installation - Manual (Page 51)

SMA Solar Technology AG 10 Cable Connection in the Connection Cabinet
Installation Manual SCxxxHE-20-IA-IEN111210 51
10.4.6 Connecting the Transformer Protection
The inverter is equipped with a connection terminal for the transformer monitoring system of the
medium-voltage transformer. This will shut down the inverter immediately in the event of a fault. To use
the transformer monitoring, an external voltage supply of 230 V/50 Hz must be provided.
1. Lead the transformer protection cable into the connection cabinet (see section 10.3).
2. Connect the cable according to the circuit diagram (see section 10.4.1).
3. Remove the shield clamp from the busbar.
4. Press the shield clamp down until it clicks into place,
and fasten hand-tight.
5. Fasten the cable to the cable anchoring rail using a cable tie. This secures the cable from being
pulled off.
10.4.7 Connecting the External Voltage Supply
The inverter draws electricity for its internal power supply from the grid via the external voltage supply.
Requirements for the external voltage supply:
• External, three-phase auxiliary supply voltage of 230 V (3/N/PE) each
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Damage to the inverter due to incorrect power supply connection
• Connect the neutral conductor 'N'.
• Ground the star point of the transformer for internal power supply.
Miniature circuit-breaker between the external voltage supply and the inverter
A type B miniature circuit-breaker with a nominal current of 16 A is installed in the inverter.
• Provide for a selective miniature circuit-breaker for insulating the cable to the inverter.
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