12
| 1.0 product Description
1.4 Major Components
The operating principle of the UPS is illustrated in Figure 3.
L1
Dynamic
Bypass
Input
DC-to-DC
Converter
Rectifier /
PFC
Inverter
Battery
Battery
Charger
L1
SPD & EMI/
RFI Filters
L2/N
Output
L2/N
G
G
Figure 3: Operating principle diagram
The UPS is composed of utility input, SPD and EMI/RFI filters, rectifier/PFC, inverter, battery charger, dc-to-dc converter,
battery, dynamic bypass and UPS output.
1.4.1 Surge Protection Device (SPD) & EMI/RFI Filters
The S4K2UC has surge protection and filters that protect the connected load from power surges, electromagnetic interference
(EMI) and radio frequency interference (RFI). These features can minimize any surges or interference present in the utility
power. The filters also prevent surges or interference generated by the UPS from adversely affecting devices connected on the
same branch as the UPS.
1.4.2 Rectifier/Power Factor Correction (PFC) Circuit
In normal operation, the S4K2UC’s rectifier/power factor correction (PFC) circuit converts utility power to regulated
dc power for use by the inverter, while ensuring that the wave shape of the input current used by the UPS is near ideal.
Extracting this sine wave input current achieves two objectives:
♦
Efficient power use by the UPS
♦
Reduced reflected harmonics
This results in cleaner power being available to other devices in the building not protected by the S4K2UC.