I've never seen a Liebert fail! Since it trips the DC
breaker, and assuming the batteries and float voltage
are ok, then the inverter is probably drawing too much
current -- maybe shorted output transistors.

ml wrote:
i got a 6kv liebert ups, trips the dc breaker on testing fail to backup

never worked on a ups before, i can say the ac side seems to be ok,
and the charger seems ok as the batteries stay floated /charged front
pannel lcd seems to work

any clues what might be a good path to start on or perhaps someone might
know what these ups typically blow?


thanks