Understanding Ups Operation; Ups System Overview; Figure 5-1. Main Elements Of The Ups System - Eaton 93E Operation Manual

Chapter 5

Understanding UPS Operation

5.1

UPS System Overview

The Eaton 93E UPS is a continuous-duty, solid-state, transformer-free, three-phase, true online system that
provides conditioned and uninterruptible AC power to the UPS system's output and critical load.
The basic system consists of a rectifier, battery converter, inverter, monitoring/operation control panel, integrated
communication server, and digital signal processor (DSP) logic. Figure 5-1 shows the main elements of the UPS
system.
If utility power is interrupted or falls outside the parameters specified in Chapter 9, "Product Specifications, " the
UPS uses a backup battery supply to maintain power to the critical load for a specified period of time or until the
utility power returns. For extended power outages, the UPS allows you to either transfer to an alternative power
system (such as a generator) or shut down your critical load in an orderly manner.
AC Input to
Rectifier/
Charger
AC Input to
Bypass
The emergency bypass consists of a continuous static switch, and an optional backfeed protection contactor. The
backfeed protection contactor (if fitted) is located in series with the static switch. The static switch is armed and
ready during normal operation.
(Optional) Input
Input Breaker Contactor
(Optional )
Backfeed Contactor

Figure 5-1. Main Elements of the UPS System

External Battery cabinet
Battery
Contactor
Battery
Converter
Rectifier
Digital Metering
Static
Switch
UPS Cabinet
Eaton 93E UPS (300/400 kVA, 380/400/415V) Installation and Operation Manual
Output
Contactor
Inverter
Power Module
AC Output to
Critical Load
5-1