5 ELECTRICAL FIELD CONNECTIONS
WARNING! Arc flash and electric shock hazard. Open all local and remote electric power supply disconnect
switches, verify with a voltmeter that power is Off and wear appropriate, OSHA-approved personal protective
equipment (PPE) per NFPA 70E before working within the electric control enclosure. Failure to comply can
cause serious injury or death. Customer must provide earth ground to unit, per NEC, CEC and local codes, as
applicable. Before proceeding with installation, read all instructions, verify that all the parts are included and
check the nameplate to be sure the voltage matches available utility power. The Liebert® controller does not
isolate power from the unit, even in the “Unit Off” mode. Some internal components require and receive
power even during the “Unit Off” mode of the controller. The factory supplied disconnect switch is inside the
unit. The line side of this switch contains live high voltage. The only way to ensure that there is NO voltage
inside the unit is to install and open a remote disconnect switch. Refer to unit electrical schematic. Follow all
local codes.
WARNING! Risk of electric shock. Can cause equipment damage, injury or death. Open all local and remote
electric power supply disconnect switches and verify with a voltmeter that power is off before working within
any electric connection enclosures. Service and maintenance work must be performed only by properly
trained and qualified personnel and in accordance with applicable regulations and manufacturers’
specifications. Opening or removing the covers to any equipment may expose personnel to lethal voltages
within the unit even when it is apparently not operating and the input wiring is disconnected from the
electrical source.
WARNING! Risk of improper wire sizing/rating and loose electrical connections. Can cause overheated wire
and electrical connection terminals resulting in smoke, fire, equipment and building damage, injury or death.
Use correctly sized copper wire only and verify that all electrical connections are tight before turning power
On. Check all electrical connections periodically and tighten as necessary.
WARNING! Risk of wiring damage, short circuits and electric shock. Can cause overheated wiring, smoke, fire,
activation of fire suppression systems and EMS personnel and equipment, building and equipment damage,
injury or death. Insert CSA certified or UL listed bushings into holes and or knockouts used to route wiring
through metal panels to protect the wire insulation from contact with sheet metal edges.
NOTICE
Risk of improper electrical connection of three phase input power. Can cause backward compressor rotation
and unit damage. Service technicians should use a gauge set on the system during the initial startup to verify
that the three phase power is connected properly. Three phase power must be connected to the unit line
voltage terminals in the proper sequence so that the compressors rotate in the proper direction. Incoming
power must be properly phased to prevent compressors from running backward. We recommend checking the
unit’s phasing with proper instrumentation to ensure that power connections were made correctly. We also
recommend verifying discharge and suction pressures during startup to ensure that the compressors are
running in the correct direction.
5 Electrical Field Connections
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