SMA SC 400HE Installation - Manual (Page 13)

SMA Solar Technology AG Safety
Installation Guide SCxxxHE-IEN104432 13
Sequence for Switching On the External Power Supplies
1. Grid voltage for grid feeding
2. Grid voltage for internal power supply
3. DC voltage from the photovoltaic generator
2.2.6 Disconnecting
External isolation of the device must always occur under load-free conditions. The device must be
switched off in order to do this, i.e. the key switch must be in the “Stop” position.
The following power supplies must be isolated:
• Grid voltage for grid feeding
• Grid voltage for internal power supply (optional)
• DC voltage from the photovoltaic generator
• Additional external voltage if necessary (e.g. emergency stop)
Simply switching off the main AC and DC switches is not sufficient to ensure proper isolation of the
device. The main switches only separate the power circuit from the grid and the photovoltaic
generator.
The DC voltage is isolated using the internal or external DC input fuses, or using an external circuit
breaker if present. Isolation by removing the DC input fuses must occur under load-free conditions.
DANGER!
Risk of lethal electric shock.
Work on the Sunny Central may be performed only after switching off the power to the
unit. The VDE regulations must be followed:
• Disconnect
• Ensure that the device cannot be reconnected
• Ensure that no voltage is present
• Ground and short-circuit the unit if necessary (not on the DC side)
• If necessary, cover or shield any adjacent live components
DANGER!
Risk of lethal electric shock.
Dangerous accidental-contact voltages can be present in the Sunny Central even when the
main AC and DC switches are switched off!
• Wait at least 5 minutes after switching off the Sunny Central.