MITSUBISHI ELECTRIC 9900B SERIES UPS
MITSUBISHI
ELECTRIC
9900B SERIES UPS
OWNERS / TECHNICAL MANUAL
Page Number:
1-9
In the event of a UPS module failure during Parallel Operation, the critical load power will be
continuously supplied and shared by all other UPS units.
CAUTION: For protection, the Bypass Input circuit breaker (MCCB) of the UPS
and cables are field supplied and field installed (see WARNING 4
on page 1-5).
B) Bypass Operation:
Load Power supplied through UPS internal static bypass line.
Figure 1.2
Single Line Diagram - Bypass Operation: Load Fed Through Static Bypass Line
UPS Module
Power Flow
AC
input
CB3
CONVERTER /
CHARGER
Output
52C
Static Transfer
Switch
52S
CB2
Battery
Cabinet
Bypass
Input
CB
User
supplied
MCCB
User
supplied
MCCB
CB
CB1
INVERTER
Not in Use
External
BATTERY
Referring to Figure 1.2: The Internal Bypass line is a hard-wired line through 52S, which
supplies the critical load with unconditioned bypass input power. Upon switching to the Internal
Bypass line, the Static Transfer Switch (STS) line through CB3 supplies the power immediately.
Then the Internal Bypass line through 52S supplies the power. In the event of switching to the
Bypass line, the power to the critical load will be uninterrupted. The purpose of this Internal
Bypass line is to route power to the critical load while the UPS module (converter and inverter)
is de-energized, and during startup before the system is operating on the UPS module.
Each UPS internal static bypass line will equally share the power supplied to the critical load
whenever the system is in Parallel Operation.
Summary of Contents for 9900B Series
Page 2: ...Preface Revision 4 06 09 2020 U ENM00030 ...
Page 74: ......
