Eaton 9315P, Installation And Operation Manual

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Operation
4-2 Eaton 9315/9390/9395/9395P Fixed Primary Sync Control Installation and Operation Manual P-164000023—Rev 03
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When the secondary system is synchronized to the primary source, a transfer to bypass disable signal is
sent to the secondary system. This inhibits any transfers to bypass on the secondary system
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If one UPS system loses its critical load bus voltage sensing, the secondary system synchronizes to its own
bypass source.
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Dual redundant logic power supplies are incorporated within the Eaton Fixed Primary Sync Control, ensuring
both systems remain synchronized even during the loss of one of the logic power supplies. If one or both
power supplies fail, an alarm is sent back to the secondary system indicating a “SYNC CONTROL
TROUBLE” alarm. These power supplies are powered from each system's critical load bus.
With a complete loss of logic power to the Eaton Fixed Primary Sync Control (due to component failure or
power supply fault), the secondary system synchronizes to its own bypass source.
Figure 4-1. Synchronization Reference Control
NOTE The Synchronization Reference Control relays are shown under normal conditions.
NOTE
Dashed switch position of Synchronization Reference Control Relay 1 shows UPS in the secondary system mode.
(Secondary)
UPS
Bypass
Voltage
Primary
System
Output
Voltage
UPS
SYNCHRONIZATION
REFERENCE
VOLTAGE
EATON
FIXED PRIMARY SYNC
CONTROL
SYNCHRONIZATION
REFERENCE
CONTROL RELAY
RELAY