PowerWalker VFI 10000TCP 3/1 Bedienungsanleitung Seite 53

Operation
If bypass thyristor is short (short circuit) and UPS runs in double
conversion mode (online) the following steps follow:
The backfeed relay opens and the message "backfeeder" is shown on the
LCD panel
Reset
To reset the backfeed logic the UPS device must be switched Off for some
seconds
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