Specifications

Document No. DER05105 TROUBLESHOOTING
Page 4 of 16 Effective Date 15 Jul 08
TROUBLESHOOTING DE-7200 CENTRIFUGE
Possible Cause Isolation Procedure & Corrective Action
Failure Mode 8: Excessively High Main Bearing Temperature
Insufficient lubrication Lubricate bearings (refer to DER05023).
Excessive grease Remove grease fitting, and direct jet of filtered compressed air
to remove grease.
Incorrect grease Lubricate with recommended grease (refer to DER05023).
Defective bearing Replace both main bearings (refer to DER05024).
ALARM AND FAULT MESSAGES
Intervention is required if a message appears to alert the operator that an anomaly has occurred.
Alarm messages signify that the prevailing condition must be corrected or the centrifuge may be
shut down automatically. Fault messages inform the operator that a failure requiring automatic
shutdown has occurred.
Refer to the following table for alarm and fault messages and their causes and corrective actions
for assistance in analyzing messages.
Alarm and Fault Messages
Cause Corrective Action
Air Conditioner Compressor Motor Overload Fault
Motor drawing excessive current Replace air conditioner compressor motor, if
defective, or remove other cause of excessive
current draw.
Air Conditioner Internal Fan Motor Overload Fault
Motor drawing excessive current Replace internal fan motor, if defective, or remove
other cause of excessive current draw.
Air Conditioner Refrigerant Pressure High or Low Fault
Check refrigerant pressure; high
pressure indicates over-charging, and
low pressure indicates system leakage
If pressure is high, reduce refrigerant quantity; if low,
correct leak(s) and re-charge system.
Bowl Exceeded Maximum Speed, Shutdown
Incorrect or loose connection at speed
sensor, or speed sensor out of
adjustment or defective
If reading on Bowl VFD status screen is about 4000
RPM, check connection (refer to DER03022
); if
connection is secure, adjust speed sensor (see
Speed Sensor Adjustment in this section). Replace
sensor if adjustment does not correct problem.
Bowl VFD has permitted bowl to exceed
maximum pre-set speed limit
Replace bowl VFD, and re-start centrifuge while
monitoring speed closely.