UPS for 480 Vac Grid, User Guide, doc. rel. 4.0
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total output requirements of the power modules are adequately covered. If there are an odd
number of power modules in the system, the extra dc converter block will insure evenly
distributing the battery charging and discharging current throughout the system.
8.2.1.2.1.
Redundancy
Redundant modules are those in excess of the minimum number of modules required to supply
the maximum expected UPS load. Each UPS module can supply 30 kVA. So, for example, if the
maximum expected load is 120kVA (4 x 30 kVA), and there are five power modules installed, one
of them can be designated for redundancy. In the event one of the five modules fails, the
redundant module ensures that the UPS will continue to be able to accommodate the maximum
expected load.
The number of redundant modules can be zero or greater, depending on the maximum expected
load and the number of available module shelves.
In reality, redundancy is not a property of any particular module. Redundancy is simply the
presence of one or more modules in excess of the number of modules required to meet the
maximum load.
As an example, let's say:
We have a UPS system with five module shelves. Each shelf can hold a 30-kVA module.
The maximum expected load is 120 kVA, and four modules (120 kVA) are required to supply the
maximum expected load.
A fifth module can be installed and a redundancy of one module declared. If any one of the
four modules fail, the UPS will still be able to supply power for the maximum expected load
(4x30 kVA). If all the modules are operating normally, and the load unexpectedly increases to
130 kW, the system indicates an overload condition, because the redundant module is not
taken into account in calculating the UPS’s maximum output capability.
When modules are added to the system or removed from the system, the value of
total number of modules must be adjusted. You may or may not at that time also
want to change the number of redundant modules.
8.2.1.3.
Setup > System > SYSTEM TYPE
8.2.1.3.1.
Multi-system mode
Indicates that the UPS will be operating in parallel configuration (multi-system mode).
