Troubleshooting; Blower Troubleshooting - Vertiv Liebert CW Series Installer And User Manual

9 TROUBLESHOOTING

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.
NOTICE
Risk of improper control circuits. Can cause equipment damage.
When using jumpers for troubleshooting, always remove jumpers when maintenance is complete. Jumpers left
connected could override controls and cause equipment damage.
Table 10.1 Blower troubleshooting
Symptom
Blower will not start
Blower runsbut
controlswill not
operate
9 Troubleshooting
Possible Cause Check or Remedy
Check L1, L2 andL3 for ratedvoltage.
No mainpower
Check Liebert®CWfor unit status(Stand-by, Unit Off, MonitoringOff or Remote Off).
Blownfuse or trippedcircuit
Check fusesor CBsto mainfan.
breaker (CB)
Overloadstripped(mainpanel
Pushreset buttononmainfanoverload. Check amp. draw.
onLiebert®CW)
No output voltage from
Check for 24VACbetweenP24-2 andP24-1. If no voltage, check primary voltage.
transformer
Control fuse blownor circuit Check for 24VACbetweenP4-4andE1. If no voltage, check for short. Replace fuse or reset
breaker tripped circuit breaker.
Check for 24VACbetweenP36-9andP36-10. If voltage isnot present, R1 isnot receiving
power.
Relay R1 not makingcontact
Check air switch. Jumper P36-4to P36-7 If R1 closes, air switchisnot closing(check for
(standardcontrolsonly)
blower rotation, loose wiringandpinchedtubing.)Remove jumper.
Check for 24VACat R1 coil. If the voltage ispresent andR1 isnot pulling, replace R1.
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