NEC SV8500, Operation And Maintenance Manual

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CHAPTER 5 Operation Procedure for System with PIR
4.10 Fan Unit Fault
This section explains the fault repair procedure where a fan in the Fan Unit (FANU) does not operate.
4.10.1 Check Point
STEP 1 If a specific fan does not work, and other fans are operating, replace the specific fan with a new
one, referring to “
Replacement Procedure of FANs (PIR/TSWR) ”.
STEP 2 If all fans do not work, do the following:
• Make sure that FAN PWR SW on the FANC (PZ-M699) is set to ON (downward).
• Make sure the voltage at the connector is -48 V. If it is less than -48 V, check the cable connection
between FANU and the PIR/TSWR.
• Replace the FANC (PZ-M699) referring to “ Replacement Procedure of FANC (PZ-M699) ”.
Figure 5-23 Circuit Diagram of Fan Unit and Thermal Unit
FAN1 FAN2 FAN3
FAN tray
FUSE ALM
-48VR
-48V
FAN ALM
PZ-M699
FANU
PIR