3Com Powerware Uninterruptible Power System Prestige Series - Manual (Page 59)

UPS Operation
53 Powerware ® Prestige Series Installation and Operator’s Manual for IBM Applications (3000 VA) Uncontrolled Copy
Using the PPDM
The PPDM provides continuous online power for your equipment. With
the PPDM, you can replace or upgrade the UPS without losing power to
your equipment. Figure 16 shows the operation of the UPS with the
PPDM.
UPS
In
Out
UPS Load
PPDM
Battery Battery Battery
Utility
Power
Figure 16. UPS and PPDM Block Diagram
Disconnecting the UPS
Use the following procedure to transfer the critical load to Maintenance
Bypass (AC Line operation) and remove the UPS:
1. Turn the Bypass switch on the PPDM to the BYPASS position
(see Figure 17). The PPDM is now powering your equipment
from utility power.
2. Press and hold the Output Off button until the long beep
ceases (approximately three seconds). The

indicator
remains lit.
3. Remove the Y-cord connections from the UPS rear panel.
C A U T I O N
Do not remove the input power cord or your equipment from the PPDM.