Mitsubishi Electric M9950 Series Technical Manual page 25

MITSUBISHI
ELECTRIC
Distributed
bypass
redundancy
system
*.Bypass input should be the same utility input. Otherwise, the cable of both bypass circuit
must be the same in length.
*.Maximum units of parallel above to 8 UPSs.
*.The internal switches 52PS and 52L keep connecting, and 52M keeps disco
nnecting during normal operation. Transfer load to external maintenance byp
ass to supply power during maintenance procedures.
The precautions for safety to operating the UPS
※1: Bypass Input/Maintenance Bypass Input/AC Input, all of them should to connect to the same 3
phase 4 wires Utility Input source.
※2: Refer to AC Input and Bypass Input (Maintenance Bypass) should be separated input power
source, only bypass input source connect to ground, and the transformer of AC Input should be
non-grounded.
※3: To prevent circuit unbalance occurred when providing power by bypass mode, to install a 1%
reactor(Variability±1%) to AC Output for each UPS would be necessary in MMS system.
M9950 SERIES UPS
OWNERS / TECHNICAL MANUAL
EXTERNAL
MAINTENANCE
BYPASS CABINET
INPUT ENTRY
CABINET
BATTERY BATTERY
CABINET 1 CABINET 2
MITSUBISHI ELECTRIC M9950 SERIES UPS
Page Number:
1-19
BYP
SW
Parallel
cabinet
UPS 1
BYP
SW
UPS 2