Specifications

Document No. DER05103 TROUBLESHOOTING
Page 2 of 5 Effective Date 25 May 07
CHECK FOR CLOGGED CONVEYOR
Troubleshooting should begin with determining if the conveyor is clogged. To check for a clogged
conveyor, proceed as follows:
1. Shut down and lock out and tag centrifuge.
2. Remove overload release assembly from gearbox, and attempt to turn gearbox pinion shaft
while restraining bowl from rotating. If pinion can be turned independently of bowl, conveyor is
not clogged.
3. Clear conveyor clogging by flushing with water or steam. If conveyor is not clogged, proceed
with troubleshooting steps below.
TROUBLESHOOTING CENTRIFUGE - FULL HYDRAULIC DRIVE
Possible Cause Isolation Procedure & Corrective Action
Failure Mode 1: Centrifuge Does Not Start
No electric power. Confirm that correct power is supplied to centrifuge and that main contactor
is closed. Correct any defects.
Vibration switch tripped. Press and hold vibration switch reset button, and attempt to re-start
centrifuge (refer to Section 4 - Operation). If machine fails to start or shuts
down soon after starting, continue troubleshooting.
Over-torque switch not reset
after tripping.
Reset overload release and over-torque switch (refer to DER05104).
Attempt to start centrifuge (refer to Section 4), and monitor vibration and
discharges for any abnormalities. Shut down centrifuge immediately upon
discovering any abnormal conditions such as no solids discharge.
Failure Mode 2: Centrifuge Starts, But Shuts Down Soon After Starting
Vibration switch tripped due
to excessive vibration during
startup.
Press and hold vibration switch reset button, and attempt re-start of
centrifuge (refer to Section 4 - Operation). If machine fails to start or shuts
down soon after starting, continue troubleshooting.
Over-torque switch tripped
due to excessive conveyor
torque.
With centrifuge fully stopped, open cover and inspect bowl interior and
conveyor for accumulated solids obstructing rotation. If clogging is evident,
water wash bowl and conveyor until liquid discharge is clear of solids. If
ambient temperature water fails to clear clogging, attempt to clear with hot
water or steam. If flushing fails to clear bowl of solids, remove rotating
assembly, remove conveyor, and manually clear all solids from the conveyor
and bowl interior. After cleaning, reinstall conveyor in bowl, and reinstall
rotating assembly (refer to Section 5 - Maintenance). Re-start centrifuge
(refer to Section 4), and monitor vibration and discharges for any
abnormalities. Shut down centrifuge immediately upon discovering any
abnormal conditions such as no solids discharge, and continue
troubleshooting.
Failure Mode 3: Centrifuge Has Automatically Shut Down
No electric power. Check that electric power is supplied to centrifuge, and check fuses. Correct
power loss; replace any blown fuse(s).
Electrical connections
incorrect.
Re-check electrical connections (refer to DER03020), and correct any
defects.