Liebert 130 kVA - Manual (Page 24)

User Manual
Hipulse - Single Phase ‘1+N’ UPS System 130 kVA - 110V
4
Overload
In the event of an overload at the Inverter output which lasts longer than the typical
time/ current (refer to Chapter 9 - Specifications), the Inverter will shut down and the
Static Transfer Switch will automatically transfer the load onto the MSS Bypass Mains
with no interruption. If the overload falls within the typical time/ current that has been
specified, the load will be returned to the inverters when the power drops to a level
which can be supported by the number of active units in the system (parallel 1+N).
In the event of a short circuit in the output, the load will normally be transferred onto
the MSS Bypass Mains, which will cause the Inverter to shut down; this switch is
determined above all by the features of the protective devices in use in the system. In
either case, an alarm message will appear on the UPS operator control panel display.
(1+N Parallel UPS System)
The control logic system constantly monitors load requirements and controls the
power supplied by the UPS modules. In the event that an overload condition is
sustained for greater than a preset time, the load will transfer to the mains bypass
supply, when the number of active modules are unable to satisfy load requirements.
The load returns to the inverter supply if the power is reduced it a value that can be
sustained by the number of active modules in the system.
Maintenance Bypass
A second bypass circuit contained in the UPS cabinet, identified as the 'Maintenance
Bypass' line is included to enable a 'raw' mains supply to be made available to the
load while facilitating a safe working environment for carrying out scheduled UPS
system maintenance or troubleshooting. The circuit is manually selected by the
Maintenance Bypass Isolator which can be padlocked in the OFF position.
WARNING
The internal maintenance bypass must not be used when the UPS
system is comprised of more than two UPS modules in parallel.
CAUTION
If an automatic circuit breaker device is not present in the input
distribution panel, there remains a dangerously high voltage at the
output busbars of the UPS module that is switched off
1.2.4 ECOMODE
In this operating mode the System prefers to put the load on the Bypass Mains, with
the Inverter on stand-by. The load is switched over to the Inverter when the mains
goes outside of standard frequency and voltage values (or the values as modified
using the operator panel when starting up the system). The ECOMODE configuration
requires a different setup in the default menu configuration, which may be prepared in
the factory before shipment or during installation by personnel trained in the use of the
System.
Note: In order to operate in ECOMODE, UPSs must be provided with compatible software versions:
The 'UPS Logic' card must be release 9.0 or later (the S/W release of the cards may be
read on the front panel display, referring to Section 4.1.2 - Operating Instructions).
Operating Instructions in ECOMODE are the same as those described in Chapter 5,
except that the load is normally on the Bypass mains, the Load LED is normally on
Inverter (5), and corresponding alarm message will be replaced with Load on Mains
(6).