MITSUBISHI
ELECTRIC
9800A SERIES UPS
OWNERS / TECHNICAL MANUAL
Page Number:
1.3 Overview
The UPS provides two power paths between the utility source and the critical load.
Figure 1.1 shows the path for normal operation, with the load powered from the inverter. Figure 1.2 shows the path for bypass operation, with the load supplied through the static bypass line.
A)Normal operation: Load power supplied by each system UPS inverter.
Figure 1.1 Single Line Diagram - Normal Operation: Load powered by UPS inverters
CB |
| Static Transfer |
AC Bypass |
| |
Input |
| Switch |
User supplied | CB3 |
|
MCCB |
|
|
RECTIFIER | INVERTER | 52S |
AC input |
| Output |
|
| |
CB1 |
| 52C |
| CB2 | Power Flow |
|
| Not in Use |
Battery cabinet |
| UPS Module |
During normal operation, the path through the UPS inverters is used to power the load.
Referring to Figure 1.1: For each system UPS, the Input AC power is converted to DC by the Rectifier. DC power is utilized to charge the UPS battery and to provide power to the Inverter. The Inverter converts the DC power to clean AC power to supply the critical load.
The conversion - inversion process eliminates any voltage transients or fluctuations existing in the input power before it reaches the critical load.
The power drawn by the critical load is equally shared between all system UPS.
In the event of a UPS module failure, the critical load power will be continually supplied and shared by all other system UPS.
In the event of a load overcurrent, all system UPS will transfer to bypass without interruption to the critical load.