HGM9560 BUS TIE MAINS PARALLEL UNIT
HGM9560 Bus Tie Mains Parallel Unit ISSUE 2013-12-30 Version 1.0 Page 19 of 51
5 MULTIPLE MAINS OPERATION
In a multiple mains system, the gensets are controlled by more than one 9560 mains controller
and used to provide power to multiple loads.
Should one or more of the mains supplies fail, the generators are started and supply power to the
load. If more than one mains supply has failed, the loads are transferred to the generators one by
one.
If one mains supply returns, the 9560 connected to that mains supply will synchronies the
generators with the mains and affect a no-break changeover. The generators continue to supply
power to the remaining loads.
If more than one mains supply returns at the same time, then the 9560 with the highest priority will
take control of the generators and affect a no-break changeover back to the mains supply.
HGM9560 priority fall into two types: status priority and module priority.
If status priorities are different, then the HGM9560 priority is up to the status priorities
；
If status priorities are same, then the HGM9560 priority is up to the module priority
；
The module priority can be set while the status priority can not.
Priority
Condition
Highest
Lowest
Auto mode, mains failed, bus not on load
Auto mode, mains has returned
Auto mode, mains failed, bus on load
Auto mode, mains available, requesting control over generators
Manual mode, sets running or about to run (start button has been
pressed)
Auto mode, mains available
Manual mode, sets not running
Stop mode
