External Bypass Switch Interlock - Emerson Liebert NX 400V User Manual

Serial Ports RS232-1 and RS232-2
RS232-1 provides serial data and is intended for direct use with Liebert MultiLink monitoring and
server shutdown software.
RS232-2 provides serial data and is intended for use by authorized commissioning and service person-
nel.
These serial ports are shared with the optional Web browser, SNMP, ModBus and relay cards. Refer
to Table 31 regarding compatibility of simultaneous use.
Intellislot Web Browser, SNMP, ModBus and Relay Cards Interface
There are three interface slots available for optional Web browser, SNMP, ModBus and Relay cards
as illustrated in 9.0 - Options—For Assembly Inside the UPS Cabinet.
1.8.6

External Bypass Switch Interlock

EXT-Maint X3-1&2 on UPS Parallel Board M3 (leave open if no external bypass switch is used)
Provides external maintenance bypass interlock protection for the UPS. Short circuit means external
bypass closed.
EXT-Out (X3-3&4) on UPS Parallel Board (leave shorted if no external output switch is used). Pro-
vides external output interlock protection for paralleled UPS modules. Short circuit means external
output switch closed.
NOTE
UPS Parallel Board M3 is located behind protective covers accessible after opening the UPS
front door—removal of this barrier requires the use of a tool and is restricted to service
personnel.
NOTE
Jumper JP1 (located next to X3) needs to be removed for X3:3&4 to work properly.
16
Single Module UPS Installation