ABB HiPerGuard MV UPS User Manual page 76

76 H I P E R G U A R D M V U P S U S E R M A N U A L
—
Figure 8.05: System
(hard parallel) after
"Precharge" process of
the DC bus is complete.
8.2.2 System start
Once sufficient MV UPS units are pre-charged, the MV UPS system is now ready to start and in bypass. In that
case, the input voltage must be within nominal conditions, and all switches are under the control of the MV UPS
(with springs charged), with input and output switches open. No warnings or active faults must be present.
The system can be controlled in three ways:
• GDM – either single UPS block, machine by machine until all are operating, or via "System view" page, all
machines can be started with the press of one button.
• Digital I/O – single UPS block, so the automation system would send the command to each individual
MV UPS block.
• Modbus TCP – single machine start, so the automation system would send the command to each indi
vidual MV UPS block.
Step User Action
1 User commands "Start"
2
3
4
5
System Response
Each MV UPS block performs a self-check.
If a MV UPS block doesn't meet pre-charge con-
ditions, its GDM will inform the User as ex-
plained in the previous section.
The MV UPS(s) synchronize(s) with utility volt-
age in magnitude, frequency and phase angle,
then it closes Sout and then Sin.
When sufficient MV UPS blocks are online (con-
figured in parameters), the group Sabp is
opened.