Output Inverter | APC LX instruction

CSI SECTION 16611 STATIC UNINTERRUPTIBLE SYSTEM

2.In cases where the source voltage to the UPS is nominal and the applied UPS load is equal to or less than 100% of UPS capacity, input current shall not exceed 130% of UPS output current, while providing full battery recharge power and importing necessary power for system losses.

F.Redundancy: The UPS shall be configured with redundant input converters, each with semiconductor fusing, and logic controlled contactors to remove a failed module from the input bus.

G.Charging:

1.The battery charging shall keep the DC bus float voltage of +/137v, +/-1%

2.The battery charging circuit shall contain a temperature monitoring circuit, which will regulate the battery charging current to optimize battery life.

3.The battery charging circuit shall remain active when in automatic Bypass and in Normal Operation.

H.Back-feed Protection: The above-mentioned logic controlled contactor also provides the back-feed protection required by UL1778.

2.6OUTPUT INVERTER

A.The UPS output inverter shall constantly recreate the UPS output voltage waveform by converting the DC bus voltage to AC voltage through a set of IGBT driven bi- directional power converters. In both normal operation and battery operation, the output inverters shall create an output voltage independent of the mains input voltage. Input voltage anomalies such as brown-outs, spikes, surges, sags, and outages shall not affect the amplitude or sinusoidal nature of the recreated output voltage sine wave of the output inverters.

B.Overload Capability: The output power converters shall be capable of 200% for short- circuit clearing. Steady-state overload conditions, of up to 130% of system capacity (N+1), shall be sustained by the inverter continuously in normal and battery operation. Should overloads persist past the outlined limitation, the critical load will be switched to the automatic bypass output of the UPS which is based upon the rating of 100A.

C.Output Contactor: The output inverter shall be provided with an output mechanical relay to provide physical isolation of the inverter from the critical bus. With this feature a failed inverter shall be removed from the critical bus.

I.Battery Protection: The inverter shall be provided with monitoring and control circuits to limit the level of discharge on the battery system.

J.Redundancy: The UPS shall be configured with redundant output inverters, each with semiconductor fusing, and logic controlled relays to remove a failed component from the critical bus.

CSI SECTION 16611 STATIC UNINTERRUPTIBLE SYSTEM