Emerson Liebert NX 10-30kVA - Manual (Page 44)

Option Installations
36
5.3.7 Emergency Power Off (EPO)
The external emergency stop facility is identical to that described for the single-unit installation—
that an individual emergency stop button is provided for each unit.
Figure 26 Connecting EPO push button
5.4 Battery Circuit Breaker Box
The box contains the same battery isolating circuit breaker as mounted in the battery cabinet.
Two battery circuit breaker boxes are available for use in installations where the battery is not
installed in the battery cabinet, in which case the appropriate battery box is fitted as close as possible
to the battery and connected to the UPS equipment as illustrated in Figure 27.
The battery circuit breaker box, is required to protect the battery from overcurrents. It also provides
electrical isolation between the UPS and the battery, permitting technical service personnel to reduce
the risks involved in maintenance work to a minimum.
A separate safety earth must be connected between the UPS unit and circuit breaker box.
Two boxes are available depending on the UPS power rating.
The circuit breaker has the following features:
• Short-circuit protection.
• Protection against battery cabinet and ups connection errors (polarity reversal +/-).
Table 7 Available battery circuit breaker boxes
UPS
Dimensions (in)
H-W-D Circuit Breaker
10-15 kVA 32.25x20.25x8.3 70A
20-30 kVA 32.25x20.25x8.3 125A
UPS2
UPS1
Monitor Board
Monitor Board
X2:1
X2:2
X2:1
X2:2
Normally
Closed EPO
UPS1
X2:3
X2:4
Monitor Board
UPS2
X2:3
X2:4 Monitor Board
Normally
Open EPO