Eaton 93PM Emergency Lighting UPS (20–40 kW, 480V Four Wire – UL 924) Installation and Operation Manual P-164000569—Rev 2 www.eaton.com/powerquality 8-1Chapter 8 UPS MaintenanceThe components inside the UPS cabinet are secured to a sturdy metal frame. All repairable parts andassemblies are located for easy removal, with very little disassembly. This design allows authorized servicepersonnel to perform routine maintenance and servicing quickly.You must schedule periodic performance checks of your UPS system to keep it running properly. Regularroutine checks of operation and system parameters enable your system to function efficiently for manytrouble-free years.8.1 Important Safety InstructionsRemember that your UPS system is designed to supply power EVEN WHEN DISCONNECTED FROM THEUTILITY POWER. The UPS module interiors are unsafe until the DC power source is disconnected and theelectrolytic capacitors are discharged. After disconnecting the utility power and the DC power, authorizedservice personnel should wait at least five minutes for capacitor bleedoff before attempting internal access tothe UPS module.WARNINGl Servicing and maintenance should be performed by qualified service personnel only.l LETHAL VOLTAGE PRESENT. This unit should not be operated with the cabinet doors open orprotective panels removed. Do not make any assumptions about the electrical state of anycabinet in the UPS system.Each battery string is an energy source in itself. DO NOT ATTEMPT TO ACCESS ANY INTERNAL AREA OFTHE BATTERY STRING YOURSELF. VOLTAGES ARE ALWAYS PRESENT IN THE BATTERY STRING. Ifyou suspect that a battery string needs service, contact an Eaton service representative.If the string requires service contact an Eaton service representative.Observe these precautions when working on or around batteries:l Remove watches, rings, or other metal objects.l Use tools with insulated handles.l Wear rubber gloves and boots.l Do not lay tools or metal parts on top of batteries.l Disconnect the charging source prior to connecting or disconnecting terminals.l Determine if the battery is inadvertently grounded. If it is, remove the source of the ground. Contact withany part of a grounded battery can result in electrical shock. The likelihood of such shock is reduced if suchgrounds are removed during installation and maintenance.l When replacing batteries, use the same number of sealed, lead-acid batteries.l Proper disposal of batteries is required. Refer to your local codes for disposal requirements.l Do not dispose of batteries in a fire. Batteries may explode when exposed to flame.l Do not open or mutilate batteries. Released electrolyte is harmful to the skin and eyes. It may be toxic.