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18 User Guide APC BC300 Series 40kW 208/450/480V UPS
990-1403
Alarms and Events
Mains is out of
tolerance (This
alarm occurs
during a power
outage)
The utility (AC input) voltage is too
high or too low, so the unit
transfers to battery operation. If
AC input returns to normal, the
unit transfers back to normal
operation. If not, the unit continues
to run on battery until the “Low DC
shutdown” alarm occurs. Then, if
bypass voltage is within the range
programmed into the UPS, the unit
transfers to bypass. If not, the unit
transfers to stand-by and does not
supply output voltage.
If possible, restore AC input
power to the UPS. If AC input is
available to the UPS, ask an
electrician to make sure that 1)
the correct input voltage is
available to the UPS, and 2) this
voltage is within a range the UPS
will accept.
OFF Button
Pushed (If the
alarm was
caused by the
Off button, it is
in the events
log)
A user pushed the red “Off” button
or activated an emergency power
off shutdown. The unit switches to
stand-by mode and does not supply
output voltage.
Restart the unit by pressing the
green button inside the door. If
the unit will not restart, the
alarm was caused by an
emergency power off (EPO)
shutdown. Find out why this
shutdown was activated and
make sure the emergency
situation has passed; then,
restart the unit by deactivating
the emergency power off
shutdown.
Output freq. is
out of tolerance
The output frequency is too high,
low, or unstable (out of tolerance).
The unit transfers to battery
operation and runs on battery until
the “Low DC shutdown” alarm
occurs. Then, the unit transfers to
bypass if bypass is within
tolerance. If not, the unit transfers
to stand-by and does not supply
output voltage.
Ask an electrician to make sure
that the correct input frequency is
being supplied to the UPS. Then,
call APC Global Service.
Output is
moment. out of
tolerance
The output voltage was
momentarily too high or too low
(out of tolerance). If bypass is
within tolerance, the unit transfers
to static bypass operation. If not,
the unit transfers to stand-by and
does not supply output voltage.
If other alarms are also active,
troubleshoot these alarms first. If
this is the only alarm, call APC
Global Service.
Table 5: Possible Alarms