Electrical Connection Requirements - Vertiv Liebert PFD Installer/User Manual

5 ELECTRICAL CONNECTION REQUIREMENTS

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 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 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.
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 start up 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 start up to
ensure that the compressors are running in the correct direction.
NOTICE
Risk of compressor slugging. Can cause equipment damage.
Apply power to the condensing unit 8 hours before operating the system. This time is required
to drive liquid refrigerant out of the compressor. This is especially important at low ambient
temperatures. The compressor's crank-case heater is energized as long as power is supplied to
the unit.
NOTICE
Risk of improper electrical supply connection. Can cause equipment damage.
See transformer label for primary tap connections. Installer will need to change transformer
primary taps if applied unit voltage is other than pre-wired tap voltage.
5 Electrical Connection Requirements 21