Sync Control for Eaton 9395P and 93PM
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User’s and Installation Guide
To maintain a fault-tolerant arrangement, the Eaton Sync Control accounts for the following fault
conditions or abnormal operating conditions:
1.
An automatic reassignment of the preferred source (master) is made if the non-master
system goes to bypass, regardless of the position of the Preferred Source Selector switch.
When the non-master system (as defined by the Preferred Source Selector switch) is on
bypass, the non-master system automatically becomes the master. The two systems
continue to synchronize to their own bypass source until one of the bypass sources become
unavailable or the two bypass sources are no longer in synchronization with each other.
2.
If one UPS system loses its critical load bus voltage sensing, each system synchronizes to
its own bypass source regardless of the position of the Preferred Source Selector switch.
3.
Dual redundant logic power supplies are incorporated within the Eaton Sync Control,
ensuring both systems remain synchronized even during the loss of one of the logic power
supplies. These power supplies are powered from each system's critical load bus.
4.
With a complete loss of logic power to the Eaton Sync Control (due to either component
failure or power supply fault), each system synchronizes to its own bypass source.
Figure 4-1 Typical Eaton Sync Control Block Diagram with a Eaton 9395P or 93PM UPS System