Eaton 91PS User And Installation Manual

Also see for 91PS: Safety and installation quick guide Safety and installation quick guide User and installation guide User and installation guide

Contents

5.8.1 Power wiring overviewSee Section4.3.2 for the recommended cable and external fuse sizes andinstallation practices.Input feedThe input feed is defined as the power source connected to the UPS rectifier.The feed to all UPS’s inputs must be derived from the same source.Bypass feedThe bypass feed is defined as the power source connected to the UPS bypass.The feed to all UPS’s bypass must be derived from the same source. Theshortest length of power wire from the source to the UPS must be a minimum of95% of the length of the longest wire.OutputThe neutrals of all the UPSs must be connected. The shortest length of wirefrom the source to the UPS must be a minimum of 95% of the length of thelongest wire. The measurement is with respect to where the UPS’s outputs aretied.Dual sourceThe input feed and bypass feed may be separate sources. The sources mustshare a common neutral.Battery connectionA separate battery shall be connected to each UPS, and the battery capacity foreach UPS must be identical. A common battery for all UPSs is not supported.MOBsModule Output Breakers (MOBs) allow the output of an UPS to be disconnectedfrom other UPSs and the system load for maintenance and service. Designconsiderations assume that each UPS has a Module Output Breaker (MOB).The breaker should also disconnect the neutral for improved safety duringmaintenance.The MOB must have a Form “C” auxiliary contact. The N.C contact is connectedto the corresponding UPS’s input used for signal input. The N.O. contact is usedto disconnect the bypass pull-chain when the MOB is open. Figure18 shows theprinciples of paralleled UPS systems including MOBs and outputs from UPSs.MOB overrideUsers without MOBs installed can simply leave the MOB signal input disabled.The user should be aware that systems without MOB have limited maintenancecapability.Parallel system cablingEaton 91PS/93PS UPS 8-10 kW User's and installation guide© Eaton Corporation plc 2018. All rights reserved. Revision: 003 Document ID: P-164000672 57 (102)