The DC boost converter derives power from the unregulated DC rectifier and produces a higher, stable DC voltage and current source for the inverter. A fixed system neutral is also carried through the boost converter to allow full support of single phase AC loads from any phase of the inverter output. The output neutral of the system is connected to the required neutral, both from the main utility supply and the bypass supply and should never be bonded to protective earth ground at the UPS output.
The inverter produces three phase AC power to a customer load without the use of a transformer. The inverter derives power from the boost converter regulated DC and utilizes IGBT devices and
If the utility AC power is interrupted or is out of specification, the UPS automatically switches to Battery mode to support the critical load with no interruption. When utility power returns, the UPS returns to normal mode.
If the UPS becomes overloaded or unavailable, the UPS switches to Bypass mode. The UPS automatically returns to Normal mode when the overload condition is cleared and system operation is restored within specified limits.
If the UPS experiences an internal failure, it switches automatically to Bypass mode and remains in that mode until the failure is corrected and the UPS is back in service.
Powerware 9335 (80 kVA and120 kVA) Installation and Operation | |
164201396 REV. A 071103 |
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