Liebert Series 600T - Manual (Page 113)

Maintenance 107
!
WARNING
EXTREME CAUTION IS REQUIRED WHEN PERFORMING
MAINTENANCE.
BE CONSTANTLY AWARE THAT THE UPS SYSTEM CONTAINS HIGH
DC AS WELL AS AC VOLTAGES. WITH INPUT POWER OFF AND THE
BATTERY DISCONNECTED, HIGH VOLTAGE AT FILTER CAPACITORS
AND POWER CIRCUITS SHOULD BE DISCHARGED WITHIN 30
SECONDS. HOWEVER IF A POWER CIRCUIT FAILURE HAS
OCCURRED, YOU SHOULD ASSUME THAT HIGH VOLTAGE MAY
STILL EXIST AFTER SHUTDOWN. CHECK WITH A VOLTMETER
BEFORE MAKING CONTACT.
AC VOLTAGE WILL REMAIN ON THE BYPASS AND OUTPUT CIRCUIT
BREAKERS, AND THE STATIC BYPASS SWITCH, UNLESS ASSOCIATED
EXTERNAL CIRCUIT BREAKERS ARE OPENED.
CHECK FOR VOLTAGE WITH BOTH AC AND DC VOLTMETERS PRIOR
TO MAKING CONTACT.
BE SURE TO READ THE BATTERY MANUFACTURER’S MANUAL
BEFORE WORKING ON OR NEAR THE BATTERY. BATTERY
TERMINALS WILL CONSTANTLY BE ENERGIZED, REGARDLESS OF
WHETHER THE UPS IS OPERATING OR NOT.
WHEN THE UPS SYSTEM IS UNDER POWER, BOTH THE OPERATOR
AND ANY TEST EQUIPMENT MUST BE ISOLATED FROM DIRECT
CONTACT WITH EARTH GROUND AND THE UPS CHASSIS FRAME BY
USING RUBBER MATS.
SOME COMPONENTS WITHIN THE: CABINETS ARE NOT CONNECTED
TO CHASSIS GROUND.
ANY CONTACT BETWEEN FLOATING CIRCUITS AND THE CHASSIS IS
A LETHAL SHOCK HAZARD. — USE DIFFERENTIAL OSCILLOSCOPES
WHEN MEASURING A FLOATING CIRCUIT. THE DIFFERENTIAL
INPUT SHOULD HAVE AT LEAST 800 Vrms COMMON MODE INPUT
RATING AND A COMMON MODE REJECTION RATIO OF AT LEAST
80dB.
EXERCISE CAUTION THAT THE TEST INSTRUMENT EXTERIOR DOES
NOT MAKE CONTACT EITHER PHYSICALLY OR ELECTRICALLY
WITH EARTH GROUND.
IN CASE OF FIRE INVOLVING ELECTRICAL EQUIPMENT, USE ONLY
CARBON DIOXIDE FIRE EXTINGUISHERS, OR OTHERS APPROVED
FOR USE IN ELECTRICAL FIRE FIGHTING