Vertiv Liebert MBSM - Signal Interconnections; Remote Contacts

Vertiv
™
| Liebert
®
MBSM
™
User Manual | 25
4.4 Signal Interconnections
UPS inhibition signals are contacts present in the Liebert MBSM to be wired to each digital input
of each UPS installed.
Bus A UPS digital input must be wired to the Liebert MBSM outputs XT1 from 21 to 26. Bus B UPS
digital input must be wired to the Liebert MBSM outputs XT1 from 27 to 32. See also Figures 15
and 16 red signal interconnections. Suggested wire size is 16AWG.
Frequency reference signals are signals available on the Liebert MBSM RJ-45 plugs XP1~ XP6.
Each UPS is equipped with an RJ-45 on the control PCB. Each UPS RJ-45 must be
interconnected to an RJ-45 XPx plug on the Liebert MBSM using a cable with the following
characteristics:
• cable type: category 5 shielded flexible stranded
• wires: 4 x 2 x AWG24 copper cable
• shielding: aluminum/polyester
• impedance: 100Ohm
• connectors: 2 x shielded RJ-45 plugs
• connections: pin-to-pin
As the length of these cables depends upon the UPS system layout, these cables are not
normally supplied by Vertiv. For this interconnection use only shielded RJ-45 cables and, possibly,
do not run these cables in the same conduit where the power cables are running. The max
theoretical length of each frequency reference cable should not exceed 100m.
4.5 Remote Contacts
Two remote contacts are available for the customer to use:
• Bus A forced = XT1 19-20
• Bus B forced = XT1 15-16
If these remote contacts/commands are not used, leave the mentioned terminals not wired. Once
these inputs are open, the Liebert MBSM will logically behave normally.