Protective Features; Fan Impellers And Bearings Maintenance; Fan Assembly Troubleshooting - Vertiv Liebert CW Series Installer And User Manual

10.2.1 Protective Features

Monitoring functions protect the motor against overtemperature of electronics, overtemperature of motor and incorrect
rotor position detection. With any of these failures, an alarm will display through the Liebert® iCOM controller and the motor
stops electronically. There is no automatic restart. The power must be switched off for a minimum of 20 seconds once the
motor is at a standstill.
The motor also provides locked rotor protection, undervoltage/phase failure detection and motor current limitation. These
conditions will display an alarm through the Liebert® iCOM.

10.2.2 Fan Impellers and Bearings Maintenance

Fan impellers should be periodically inspected and any debris removed. Check to see if they are tightly-mounted on the fan
shaft. Rotate the impellers and make sure they do not rub against the fan housing.
Shaft bearings may be equipped with Zerk fittings. Contact the manufacturer for the type of lubricant and greasing
intervals. The bearings should be inspected for signs of wear when the belts are adjusted. Shake the pulley and look for
movement in the fan shaft. Replace the bearings if excessive movement is noticed. However, the cause of the wear must be
determined and corrected before returning the unit to operation.

10.2.3 Fan Assembly Troubleshooting

Any safety hazards stemming from the device must be re-evaluated once it is installed in the end device.
Do not make any modifications, additions or conversions to the fan assembly without the approval of Vertiv.
WARNING! Risk of electric shock. Can cause serious 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 the fan-motor electric-connection enclosures. Fan-motor controls can maintain
an electric charge for 10 minutes after power is disconnected. Wait 10 minutes after power is
verified as off before working within the electric control/connection enclosures. Use only fully-
trained and qualified HVAC technicians to perform maintenance on the fans.
WARNING! Risk of contact with high-speed rotating fan blades. Can cause serious injury or
death. Open all local and remote electric power-supply disconnect switches, verify with a
voltmeter that power is off, and verify that all fan blades have stopped rotating before working
in the unit cabinet or on the fan assembly. If control voltage is applied, the fan motor can restart
without warning after a power failure. Do not operate the unit with any or all cabinet panels
removed.
CAUTION: Risk of exposure to harmful noise levels. Can cause hearing injury or loss.
Depending on the installation and operating conditions, a sound pressure level greater than
70 dB(A) may arise. Take appropriate technical safety measures. Operating personnel must
wear appropriate, OSHA-approved PPE and observe all appropriate hearing-protection safety
requirements.
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Vertiv | Liebert® CW™Installer/User Guide