Emerson 250-400kVA - Manual (Page 7)

1
I
MPORTANT
S
AFETY
I
NSTRUCTIONS
SAVE THESE INSTRUCTIONS
This manual contains important instructions that should be followed during installation and mainte-
nance of your Liebert NXL UPS and batteries.
This equipment contains circuitry that is energized with high voltage. Only test equipment
designated for troubleshooting should be used. This is particularly true for oscilloscopes. Always
check with an AC and DC voltmeter to ensure safety before making contact or using tools. Even when
the power is turned Off, dangerously high voltage may exist at the capacitor banks.
Observe all battery precautions when near the battery for any reason.
ONLY properly trained and qualified service personnel should perform maintenance on
the UPS system. When performing maintenance on any part of the equipment under power, service
personnel and test equipment should be standing on rubber mats. The service personnel should wear
insulating shoes for isolation from direct contact with the floor (earth ground).
One person should never work alone. A second person should be standing by to assist and summon
help in case an accident should occur. This is particularly true when work is performed on the bat-
tery.
!
WARNING
Risk of electric shock. Can cause equipment damage, injury or death.
Exercise extreme care when handling UPS cabinets to avoid equipment damage or injury to
personnel. Refer to separate installation manual for equipment handling information and
installation procedures.
Follow all battery safety precautions in 3.0 - Maintenance when installing, charging or
servicing batteries. In addition to the hazard of electric shock, gas produced by batteries can
be explosive and sulfuric acid can cause severe burns.
In case of fire involving electrical equipment, use only carbon dioxide fire extinguishers or
others approved for use in electrical fire fighting.
Extreme caution is required when performing maintenance. Service and maintenance work
must be performed only by properly trained and qualified personnel and in accordance with
applicable regulations as well as with manufacturers’ specifications.
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, assume that high voltage still exists after shutdown. Check with a voltmeter before
making contact.
AC voltage will remain on the system bypass, the UPS output terminals 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.
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 the chassis ground. Any contact
between floating circuits and the chassis is a lethal shock hazard. Exercise caution that the
test instrument exterior does not make contact, either physically or electrically, with earth
ground.