User's Guide Power Supply 9170

Powerware

9170 User's Guide  LTM-1344 B Uncontrolled Copy

C H A P T E R 1

INTRODUCTION

The Powerware 9170 uninterruptible power system (UPS) is a modular

UPS that contains battery modules and power control modules (referred

to as power modules). These modules plug into a rack cabinet structure

containing additional control, communication, and display functions

that enable integrated control of all power modules. The UPS is housed

in a single cabinet, with extra battery capacity housed in auxiliary

battery cabinets.

The pluggable power modules can be removed and replaced

(hot-swapped) without powering the UPS down if the UPS has sufficient

redundant capacity. Battery modules may also be hot-swapped for

maintenance. Power control circuitry in the cabinet senses problems in

power modules, and automatically transfers control and load to the

remaining power modules.

All power modules share the load requirements equally. For example,

three power modules are capable of supplying a total of 9 kVA. If a load

requires only 4.5 kVA, each power module supplies 1.5 kVA to the

output. If one power module is removed or for some reason fails, each of

the two remaining power modules would supply half of the load, or

2.25 kVA. In other words, redundancy exists when the load can be

supplied by less than all of the installed power modules.

The UPS can be configured with up to seven power modules; its output

is limited such that an excess number of power modules allow the

failure of one or more modules without causing the UPS to lose any

functionality.

To permit UPS removal from the power path, while maintaining power

to the loads, an external bypass switch is required. This switch is

optional but recommended for system serviceability.