Distributed Bypass System; Input Output Module Configuration; Continuous Static Switch; Inherent Redundancy - Eaton Power Xpert 9395 Installation And Operation Manual

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Refer to the Eaton Power Xpert
(P.164000610) manual for installation instructions.
1.4.5

Distributed Bypass System

There are two types of redundancy: UPS based (based on the number of UPSs) and UPM based (based on the
number of UPMs).
NOTE All UPSs in the distributed bypass system must contain the same number of UPMs.
Mixed UPS kVA ratings are not permitted.
A distributed bypass UPS system can be installed to provide a capacity and/or redundant system. This load
sharing system provides more capacity than a single UPS, and can provide backup, depending on the load and
configuration. In addition, when one UPM is taken out of service for maintenance or is not operating properly,
a redundant UPM continues to supply uninterrupted power to the critical load. A Hot Sync Controller Area
Network (CAN) Bridge Card provides connectivity and operational mode control.
The tie cabinet is provided by the customer and must contain Module Output Breakers (MOBs) with dual
auxiliary contacts for control of the system. Without dual auxiliary MOBs, UPMs are not allowed to go to bypass
individually during servicing. All UPMs will go to bypass instead of just the UPM needing service, decreasing
critical load protection. With dual auxiliary MOBs, one UPM can be bypassed while the remaining UPMs
support the load as long as the remaining UPMs have the capacity to do so.
1.4.6

Input Output Module Configuration

The UPS can be supplied in an Input Output Module (IOM) configuration without the bypass input connections,
the static switch, and the backfeed protection contactor. This configuration is primarily used in multiple UPS
parallel systems that do not need a bypass for each UPS and use a separate System Bypass Module (SBM) to
provide system bypass capabilities.
1.4.7

Continuous Static Switch

A continuous static switch is used to provide transfer of the load from the inverter to the bypass source in the
event the inverter become unavailable.
1.4.8

Inherent Redundancy

To deliver greater reliability, the 9395P-300 UPS can be configured by an authorized Eaton Customer Service
Engineer for inherent redundancy. When configured, the UPS automatically becomes redundant if the load is
at or below the capacity of the UPMs minus the capacity of one UPM. Under normal conditions the UPMs in
the UPS share the load equally. If one or more UPMs becomes unavailable and the load is at or below the
capacity of remaining UPMs, the remaining UPMs supply the load instead of transferring to bypass.
If the capacity of the UPMs falls below the redundancy level or the load increases above redundancy level, but
is still able to maintain the load, a loss of redundancy alarm is sounded. If the load exceeds the capacity of
remaining UPMs, the UPS transfers to bypass.
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Eaton Power Xpert 9395P-300 (300kVA, 300kW) UPS Installation and Operation Manual
®
9395/9395P UPS (1000.1200 kVA) Single.Feed Kit Installation Instructions
P-164000563—Rev 04 www.eaton.com/powerquality
Introduction
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