Emerson 115-480 Manuel D’Utilisation

Observe the safety precautions in Important Safety Instructions on page 1.
Only properly trained and qualified personnel should perform maintenance on the UPS system.
Observe all of the warnings and cautions below before performing any maintenance on the UPS 

system and associated equipment. Also observe the manufacturer's safety precautions pertaining to 

the battery, along with the battery safety precautions in this section.

Risk of electrical shock and arc flash. Can cause property damage, injury and death.
Only Liebert

®

 or Liebert-trained service personnel should work on this equipment. Both AC 

and DC high voltages are present in lethal amounts within this equipment. Extreme care 

should be taken when working around UPS equipment.
Always identify the source of connecting wiring prior to disconnecting. Mark any disconnected 

wires, so they can be properly reconnected. 
Do not substitute parts except as authorized by Liebert Corporation.
Maintain the UPS cabinets free of foreign materials such as solder, wire cuttings, etc.
Call Liebert Services if you are not sure of the procedures to follow or if you are not familiar 

with the design or operation of the equipment.

Risk of electrical shock and arc flash. Can cause property damage, injury and death.
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 contactors 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 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 8odb.
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.