GE Industrial Solutions Zenith - Energy Commander Paralleling Switchgear (PSG) - Manual (Page 3)

Uptime
Systems in which part of the load is very critical may
be best served by paralleling one or more generator
sets. Under parallel operation all the generator sets
are started at once. The first set to reach the proper
parameters will assume the most critical portion of
the load, with the remaining sets picking up lower
priority loads. In addition, by using a load shedding
application, the failure of one generator set will not
interrupt power to the critical loads, as less important
loads can be dropped o
ff the line.
Flexibility
Paralleling power sources allows for a wide variety
of choices in the generation, distribution and utilization
of the system’s power.
Capital Cost Savings
Savings can be realized on the application when a
number of smaller generator sets would be less
expensive than one large set or when the load
makes it impractical to divide into several sections,
each with it’s own generator.
Operational Cost Savings
Savings can also occur on the operation side when
generator set life is extended from being used only
when needed to support the load. Also, when it is
anticipated that the load will grow significantly in the
future, the capital investment can be reduced by
starting with small sets and paralleling additional
units as load increases dictate.
Uninterruptible Maintenance
When one engine - generator set is out of service for
maintenance or repair, having others synchronized
on the same bus can provide the needed back-up
power, should an outage occur.