APC 480 Stereo System User Manual


 
22 InfraStruXure System - Installation and Start-Up
Connect an Emergency Power Off Switch
Overview
To provide a mechanism for
emergency power off, attach a
remote switch (not included) to the
EPO interface on the PDU
monitoring unit. The EPO
interface (
) is connected to the
PDU Main Input switch (
) and
to the UPS internal EPO switch
(
).
When the EPO is activated, the
main input breaker to the PDU
transformer is opened, the UPS
DC Disconnect breaker is opened,
and the UPS System Enable switch is turned off. In this sequence, there is no power from the PDU
transformer and there is no power from the UPS inverters and batteries.
Note: Contact closure is recommended.
Connecting the switch. The Emergency
Power Off (EPO) switch connects to the PDU
user connection plate. The figure on the right
shows the location of the user connection plate
on the roof of the PDU. Connect a switch using
one of three following connections:
Contact closure
•24Vac
•24Vdc
Note: APC offers an optional InfraStruXure EPO System (EPW9). Contact your APC sales
representative, or visit the APC Web site (www.apc.com) for more information.