Emerson 7400 User Manual
Page 26
17
Series 7400 Single Phase 1+N UPS
How to turn ON the System from a Maint. power-down condition
(Complete this action on module at a time)
This procedure should be followed to start the one-plus-one from a MAINTENANCE
power-down condition - i.e. where the load is being initially powered through the
internal maintenance bypass supply.
Step Action
Response
1.
Check that the UPS mains supply
(and bypass supply, if separate) is
turned on externally.
2.
Close the input isolator (and static
bypass isolator if separate. For 110V
systems Static bypass isolator is
mounted in auxiliary cubicles).
3.
Wait 20 seconds then close the
battery circuit breaker.
4.
Press the battery metering selector
switch [B] (S4).
5.
Press the Inverter OFF pushbutton
(S6).
6.
Close the Output Isolator
7.
Open the Maintenance Bypass
Isolator on both modules then
Press the Inverter ON switch (S7) on
both modules.
(Note: The inverters of both modules are
inhibited if either modules’ Maintenance
Bypass Isolator is closed).
Mimic panel LEDs LS1 and LS3 should
illuminate immediately, to indicate that
the input and bypass supplies are
healthy.
Inverter will not turn ON unless output
isolator is closed.
Inverter will not turn ON for 1+1
configuration at this stage.
Inverter will not turn ON at this stage with
output isolator open if modules are in
1+1 configuration.
Mimic panel LED LS2 should illuminate.
The display should indicate a positive (+)
battery charging current.
Mimic panel LED LS4 should extinguish
Mimic panel LED LS5 should illuminate to
indicate that load is connected to the
static bypass line.
(Note: In a Redundant Module system LS5 will
not illuminate on the second module to be
started as its static bypass line is inhibited).
Mimic panel LEDs LS4 (Inverter OK)
and LS6 (Load on Inverter) should
illuminate after approximately 30
seconds. (NB: In a Non-Redundant
Module system LS6 will not illuminate
on the first module to be started until
you reach this point in starting the
second module).
LS5 should extinguish at the same
time as LS6 illuminates.
LS7 (alarm) should extinguish.