SMA Solar Technology AG
Power supply failure caused by unexpected stop of a genset due to reverse power protection
To ensure that a genset is protected from backfeed damage, reverse power protection must be enabled and
configured in the Fuel Save Controller and the genset. The parameters on the Fuel Save Controller and the genset
must be configured so that the reverse power protection is always triggered at the Fuel Save Controller first. If the
reverse power protection first triggers in the genset, this results in an unexpected stop of the genset which cannot be
foreseen by the Fuel Save Controller. The unexpected stop of a genset may result in a power failure in the entire PV
diesel hybrid system.
• Only use gensets with reverse power protection which fulfill the reverse power limits of the Fuel Save Controller
(see installation manual of the SMA Fuel Save Controller).
• Ensure that the reverse power protection of the gensets is always active when operating the
Fuel Save Controller.
• Adjust the reverse power protection parameters to ensure that reverse power protection always triggers first at
the Fuel Save Controller and only then at the genset.
Procedure:
1. Go to Control Functions > Genset control functions > Reverse power management via the page and
menu selection.
2. Set the desired parameters (see Section 4.8.3, page 20).
8.1.3
Setting the Supply of Sufficient Reserve Power via Gensets
Parameter overview
Figure 32: Genset Power Management: Power management of gensets: settings for reserve power
User Manual
8 System Control
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