Specifications

Document No. DER05103 TROUBLESHOOTING
Page 4 of 5 Effective Date 25 May 07
TROUBLESHOOTING CENTRIFUGE - FULL HYDRAULIC DRIVE
Possible Cause Isolation Procedure & Corrective Action
Failure Mode 4: Feed Pump Fails to Start
Feed pump motor
overheated due to
excessive current draw.
Allow sufficient time for motor to cool, and then press PUMP ON button to
attempt re-start of feed pump. If pump starts, adjust feed rate to avoid
overloading pump and monitor operation until confident of no recurrence.
Feed pump motor
overheated and/or starter
thermal overloads tripped
due to excessive current
draw.
Allow sufficient time for starter overload to cool, and then press pump starter
RESET button. Press PUMP ON button to attempt re-start of 12feed pump.
If pump starts, adjust feed rate to avoid overloading pump and monitor
operation until confident of no recurrence.
Defective pump run relay
CR2.
Shut down, lock out, and tag out electric power to centrifuge. Disconnect
lead 10 from centrifuge relay CR1, and check for continuity from terminal 10
to ground. If continuity is not found, replace relay.
Failure Mode 5: Excessive Vibration Causes Vibration Switch To Trip
Drooping of wall cake or
dislodged tiles causing bowl
imbalance.
With centrifuge fully stopped, open cover and inspect bowl interior and
conveyor for accumulated solids on one side of bowl. Water wash bowl and
conveyor until liquid discharge is clear of solids. If unable to clear bowl of
solids, or if dislodged tiles are found, remove rotating assembly, remove
conveyor, and manually clear all solids and dislodged tiles from the
conveyor and bowl interior. After cleaning, reinstall conveyor in bowl, and
reinstall rotating assembly (refer to Section 5 - Maintenance).
Gearbox misaligned Shim gearbox in accordance with DER05105 - Preventive Maintenance.
Loose components Inspect for loose components, and re-tighten as necessary.
Worn bearings Inspect and replace bearings, if worn.
Flexible connections not
installed
Install flexible connections where required.
Failure Mode 6: Incomplete Dryness
Pond depth too deep. Adjust liquid discharge ports on bowl head.
Conveyor speed too high. Reduce conveyor speed.
Feed rate too high. Reduce feed rate.
Bowl speed too low. Increase bowl speed.
Failure Mode 7: Unacceptable Clarity Of Discharge Liquid
Pond depth too shallow Adjust liquid discharge ports on bowl head.
Feed temperature too high. Adjust temperature
Degradation of feed. Check feed particle size. If too large, discontinue feed to centrifuge until feed
is satisfactory.