Operation
2.3.4Off Battery
The battery plant can be disconnected from the UPS, if required for battery maintenance, by opening the module battery disconnect (MBD) circuit breaker. In this situation the UPS module will continue to supply conditioned power to the critical load, but if input power fails the UPS system cannot supply power to the load.
! CAUTION
When the UPS system is operating with the module battery disconnect (MBD) circuit breaker(s) open, the critical load is not protected from loss of the utility source power.
Figure 27 Load on UPS, battery not available
Bypass
BFB
Input | DC Bus |
| CB1 |
CB2
Module Output
Battery System
MBD
2.3.5Emergency Module Off
The Local Emergency Module Off (LEMO) mode will transfer the critical load to the bypass line and remove power from all UPS module components except the controls, bypass circuit breaker and the static switch.
The Emergency Module Off control is a guarded pad next to the display touchscreen (Figure 2).
Lift the cover and press the pad. The load will be transferred to bypass, and the battery (MBD), input and output circuit breakers will be opened (tripped). Refer to 2.5 - Shutdown Procedures.
Figure 28 Emergency modules off
Bypass
BFB
Input
CB1
DC Bus |
CB2
Module Output
Battery System
MBD
22
