Troubleshooting guide (continued) – Liebert UPSTATION GXT 2U User Manual
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26
AC LED is flashing. UPS detected a line-to-
neutral reversal or a loss
of proper grounding;
continuous horn and
UPS will not start.This is
active only when power
is first applied to the
input. Once the UPS is
running, the AC LED will
not start flashing, even if
the input wiring is
changed.
Contact a qualified electrician to
verify site wiring.
Battery LED is
flashing.
Battery source is not
available; continuous
horn.
Check battery connections,
completely power down and
restart UPS.
NOTE: If the battery circuit
opens while the UPS is running,
it will be detected when the next
battery test is performed.
Bypass LED is
flashing.
Bypass voltage is
present, but is disabled
for use because the
voltage or frequency is
outside acceptable limits.
The AC input powers the PFC
input and serves as the bypass
source. If the AC is present but
the voltage or frequency
exceeds the acceptable range
for safe operation with a load,
the bypass will be disabled and
this LED will flash, indicating that
the bypass is unavailable.
Troubleshooting Guide (Continued)
Problem
Cause
Solution