Figure 1.3 Single Line Diagram-Emergency Operation - Mitsubishi Electric 9900B Series Owner Technical Manual

MITSUBISHI
ELECTRIC
In the event of a load overcurrent, the UPS transfers to bypass without interruption to the
critical load. In the case of Parallel Operation, all UPS units will transfer to bypass without
interruption to the critical load.
The internal control system determines the operation of the two paths, with the load powered
from the inverter being the normal operation.
C) Emergency Operation: Load Power supplied by UPS battery.
Figure 1.3 Single Line Diagram - Emergency Operation
CB
Bypass
Input
User
supplied
MCCB
CB
AC
input
User
supplied
MCCB
Referring to Figure 1.3: In the event of an AC input source failure or interruption, the UPS
Converter(s)* will de-energize and the UPS battery(s)* will immediately discharge and supply
DC power to the Inverter to maintain continuous AC power to the load. This operation will
continue until:
a) The battery capacity expires and the inverter turns off, or
b) The input power is restored, after which the converter will power the inverter and critical
load and simultaneously recharge the batteries.
A fully charged battery will provide power for the specified time at the rated load, or longer at a
reduced load.
MITSUBISHI ELECTRIC 9900B SERIES UPS
9900B SERIES UPS
OWNERS / TECHNICAL MANUAL
UPS Module
CONVERTER /
CHARGER
CB1
Battery
CB2
Cabinet
External
BATTERY
52S
CB3
Static Transfer
Switch
INVERTER
52C
Power Flow
Not in Use
(s)*: In the case of the Parallel Operation
Page Number:
1-10
Output