Liebert 7400 Series User Manual page 109

7400 Series UPS User Manual
Single Module and One plus One Systems
LED NORMAL
NUMBER STATE
LS1 ON
LS2 ON
LS3 ON
LS4 ON
LS5** OFF
6310018a.02.doc
ACTIONS TO BE TAKEN IF ABNORMAL
If this led is OFF it signifies a problem either with the incoming mains supply or
the rectifier section. See accompanying alarm messages.
Check the following:
a) Input isolator is closed.
b) Input supply voltage is within 20% of nominal.
c) Input fuses are OK.
d) Power supply fuses are OK (Note: LS1 and LS2 on the AC Power
Supply Board will be OFF if either of these fuses are ruptured).
e) Mains sensing fuses on the High Voltage Interface board F4,F5,F6.
are OK
f) Check that slide switch I3 on the UPS Logic Board is closed.
g) Phase rotation of the incoming supply and cables is correct
If the above checks prove unsatisfactory then seek qualified assistance.
If this led is OFF it signifies that either the battery circuit breaker is open or that
the dc busbar voltage is below 320 Vdc.
Note: The dc busbar low voltage level is 330 Vdc for a 400V input supply and 340
Vdc for 415V input supply. The battery circuit breaker will open automatically if
the dc voltage falls below these levels.
Check the following:
a) Battery circuit breaker is closed.
b) DC busbar voltage - if not above 320V (330 Vdc for a 400V input
supply and 340 Vdc for 415V input supply ) then carry out checks as
per LS1 (mains failure) above. If the dc busbar voltage is greater than
320V(330 Vdc for a 400V input supply and 340 Vdc for 415V input
supply ) but you are unable to close the battery circuit breaker then
seek qualified assistance.
c) If the battery circuit breaker trips as soon as mains power is
disconnected then check the dc power supply fuses.
If this led is OFF it signifies either that the bypass supply is not within acceptable
tolerances or that the bypass supply isolator is open (in a split bypass system).
Check that the bypass circuit breaker is closed, the supply is available and within
specification, and phase rotation is correct.
If this led is OFF it signifies that the inverter is not producing its correct output
voltage.
Check the following:
a) If [OVER TEMPERATURE] OR [OVERLOAD] alarm messages are
active then (after allowing the UPS to cool / checking that the load
current on the bypass line is not excessive) press the reset switch (PS1)
on the UPS Logic Board.
b) Press the Inverter ON pushbutton on the mimic display.
c) If the dc busbar is below 320V (330 Vdc for a 400V input supply and
340 Vdc for 415V input supply ) hen do checks as per LS1 above.
d) Check that slide switch I2 is closed on the UPS Logic Board.
e) If the inverter works OK when mains is available but not when mains is
unavailable then check the dc power supply fuses.
If the above checks prove unsatisfactory then seek qualified assistance.
If this led is ON then it signifies that the load has been transferred to the static
bypass supply and the output circuit breaker is closed. This indication should be
mutually exclusive with LS6 described below - check out LS6 actions.
Chapter 6 - Troubleshooting
Troubleshooting UPS System
Issue 2
(02/98) LCA 10/01
6-3